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INTERLEUKIN 2
LATEST LITERATURE
1: Journal of molecular biology, 2010 Sep 2, 103(6)
IL-2 induces conformational changes in its preassembled receptor core which then migrates in lipid raft and binds to cytoskeleton meshwork.
[Abstract]While interleukin-2 (IL-2) clearly in vitro initiates the sequential assembly of its soluble receptor fragments (sIL-2R), with sIL-2Ra first, sIL-2Rb second and sgc last, the assembly mechanism of full-length subunits (IL-2R) at the surface of living lymphocytes is still to be elucidated. Here we demonstrate by fluorescence cross-correlated spectroscopy (FCCS) that native IL-2Rb and gc assemble spontaneously at the surface of living human leukemia T-cells (Kit-225) in the absence of IL-2 and with 1:1 stoichiometry. The dissociation constant of the membrane-embedded IL-2Rb/gc complex is measured in situ. FRET analyzed by confocal microscopy on transfected-COS-7 cells between combination pairs of various length receptor chain constructions using GFP derivatives as cytoplasmic carboxy-terminal extensions, showed that IL-2Rb:ECFP and gc:EYFP bind each other through their extracellular domains, and that IL-2-binding brings their transmembrane domains 30A closer together. These observations demonstrate that IL-2Rb/gc heterodimers are preformed and their cytoplasmic domains, carrying Jak1 and Jak3, are pulled and tethered together on cytokine binding, triggering signaling transduction. IL-2 binding stabilizes IL-2/IL-2R complexes in membrane nanodomains that promotes Jak1/Jak3 phosphorylation, complexes then interact with the cytoskeleton that slows receptor diffusion as measured by FCCS and that promotes STAT5 phosphorylation. Separation of IL-2-activated receptors from triton-lyzed cells in detergent-resistant membrane nanodomains by ultracentrifugation on sucrose gradient confirmed their presence in lipid rafts. The release of IL-2-activated receptor in cytochalasin-treated cells and IL-2-induced recruitment of actin and tubulin, analyzed by immunoprecipitation, confirmed that the activated receptor interacts with the cytoskeleton. Although IL-2Ra, the third chain that gives the IL-2Rb/gc receptor core its high affinity for IL-2, is highly expressed at the cell surface and mainly clustered in membrane microdomains at the surface of Kit-225 cells, the few free IL-2Ra present bind last to the IL-2/IL-2Rb/gc complex and lock IL-2 to its binding site for prolonged action, promoting signal amplification.
2: Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology, 2010 Sep, 26(9)
[IL-2 stimulated responses of CD3(+);CD56(+);NKT cells in pulmonary tuberculosis patients.]
[Abstract]AIM: To observe the activation and proliferation characteristics of IL-2 stimulated CD3(+);CD56(+); NKT cells in pulmonary tuberculosis (PTB) patients. METHODS: Peripheral blood mononuclear cells (PBMCs) from PTB patients and normal subjects were stimulated with IL-2 and cultured for different time points. The CD69 expression on and amount of the CD3(+);CD56(+); NKT cells were detected by multi fluorescence staining and flow cytometry at different time of stimulation and culture. RESULTS: There was no significant difference in percentage of NKT cells between PTB patients and normal healthy controls before culture. When IL-2 was used to stimulate for 0 h, 8 h, 16 h, 40 h and 64 h, the expression of CD69 on NKT cells in normal controls and PTB patients increased significantly, but the CD69 expression level of NKT cells in PTB patients was significantly higher than that in normal persons(P<0.05). In PTB patients group, PBMCs were expanded significantly after stimulated by IL-2, the absolute number of NKT cells increased from (3.44+/-1.20)x10(4); to (323.23+/-75.98) x10(4); (P<0.01), expanded by 108.69+/-59.22 fold, In normal control group the absolute number of NKT cells increased from (5.57+/-5.16)x10(4); to (1475.05+/-868.98)x10(4); (P<0.01), expanded by 246.26+/-134.06 fold, the expanding efficiency in PTB group was significantly lower than that in normal control group (P<0.05). CONCLUSION: NKT cells in PTB patients present with high activation but low proliferation after stimulated by IL-2.
3: Oncology reports, 2010 Oct, 24(4)
Up-regulation of NKG2F receptor, a functionally unknown killer receptor, of human natural killer cells by interleukin-2 and interleukin-15.
[Abstract]The NKG2 family receptors are C-type lectin, type II transmembrane molecules, and play important roles in regulation of natural killer (NK) cell functions against tumor and virus. NKG2F is a new member of NKG2 family, and may possibly associate with DAP 12 to activate NK cells. Since lacking available antibody against human NKG2F, the features of NKG2F expression on NK cells remains unclear. In this study, human NKG2F recombinant expression in E. coli was carried out by using pET-28a with a hexahistidine (6x His) tag and a thrombin digestion sequence to the N-terminus of the recombinant protein NKG2F. IPTG (isopropyl-beta-d-thio-galactoside) induction resulted in high expression of recombinant NKG2F protein, which was then purified and identified by anti-His western blotting and LC-MS/MS. Polyclonal antibody was produced by immunization of BALB/c mice with recombinant NKG2F, and then used to detect NKG2F in western blotting and flow cytometry. Our results demonstrated that NKG2F was expressed only by PBMCs but not by human NK cell lines such as NKL and YT at mRNA level. It was observed that NKG2F was expressed on surface of human blood NK cells, and may be up-regulated at mRNA level and protein level after IL-2 or IL-15 stimulation.
4: Journal of leukocyte biology, 2010 Aug 20, 33(7)
Clusterin synergizes with IL-2 for the expansion and IFN-{gamma} production of natural killer cells.
[Abstract]CLU is a secreted, multifunctional protein implicated in several immunologic and pathologic conditions. As the level of serum CLU was shown to be elevated during inflammatory responses, we questioned if CLU might interact with circulating lymphocytes leading to functional consequences. To assess this possibility directly, mouse splenocytes and purified NK cells were cultured with varying dose of CLU, and its effect on cell proliferation was examined. Our data showed that CLU up-regulated DNA synthesis and expansion of NK cells significantly in response to a suboptimal, but not maximal, dose of IL-2, and CLU alone did not exhibit such effects. This CLU-mediated synergy required the copresence of CLU at the onset of IL-2 stimulation and needed a continuous presence during the rest of the culture. Importantly, NK cells stimulated with CLU showed increased formation of cell clusters and a CD69 activation receptor, representing a higher cellular activation status compared with those from the control group. Furthermore, these NK cells displayed elevated IFN-gamma production upon RMA/S tumor target exposures, implying that CLU regulates not only NK cell expansion but also effector function of NK cells. Collectively, our data present a previously unrecognized function of CLU as a novel regulator of NK cells via providing costimulation required for cell proliferation and IFN-gamma secretion. Therefore, the role of CLU on NK cells should be taken into consideration for the previously observed, diverse functions of CLU in chronic inflammatory and autoimmune conditions.
5: Journal of neuroimmunology, 2010 Aug 20, 33(7)
A novel galectin-1 and interleukin 2 receptor beta haplotype is associated with autoimmune myasthenia gravis.
[Abstract]Galectin-1 (LGALS1) and interleukin receptor 2beta (IL2Rbeta) are regulators of T-cell activation. Here we evaluated the association of regulatory region polymorphisms of the LGALS1 (rs4820293, rs4820294) and IL2Rbeta (rs743777, rs228941) genes in 146 Caucasian myasthenia gravis patients compared to 291 ethnically matched controls. A significant difference was found in the distribution of the rs4820293/rs743777 polymorphism haplotypes (p<0.01). The rs4820293 polymorphism, previously not described to be associated with any disease, does not affect LGALS1 expression in peripheral mononuclear cells and skeletal muscle. Pathway analysis revealed interaction between LGALS1 and IL2Rbeta suggesting a role of these proteins in this rare disease.
6: Current medicinal chemistry, 2010 Aug 16, 33(7)
Interleukin 2 in Cancer Therapy.
[Abstract]Cancer immunotherapy with interleukin-2 (IL-2) has demonstrated long term disease control in metastatic renal cell carcinoma and malignant melanoma. With introduction of novel kinase inhibitors, immunomodulatory molecules, cytokines, and vaccines for treatment of cancer there is an increased interest in combining these therapeutic strategies with IL-2. Here we discuss toxicity and established activity of IL-2 in the management of advanced malignancies, and speculate on future use of this cytokine for treatment of cancer.
7: Current topics in microbiology and immunology, 2010 Aug 12, 20(16)
Small-Molecule Inhibitors of IL-2/IL-2R: Lessons Learned and Applied.
[Abstract]The IL-2:IL-2R protein-protein interaction is of central importance to both healthy and diseased immune responses, and is one of the earliest examples of successful small-molecule inhibitor discovery against this target class. Drug-like inhibitors of IL-2 have been identified through a combination of fragment discovery, structure-based design, and medicinal chemistry; this discovery approach illustrates the importance of using a diverse range of complementary screening methods and analytical tools to achieve a comprehensive understanding of molecular recognition. The IL-2 story also provides insight into the dynamic nature of protein-protein interaction surfaces, their potential druggability, and the physical and chemical properties of effective small-molecule ligands. These lessons, from IL-2 and similar discovery programs, underscore an increasing awareness of the principles governing the development of drugs for protein-protein interactions.
8: The Journal of antimicrobial chemotherapy, 2010 Aug 11, 20(16)
IL-2 therapy: potential impact of the CD4 cell count at initiation on clinical efficacy--results from the ANRS CO4 cohort.
[Abstract]Objectives We investigated why, despite its beneficial effect on the CD4 cell count, IL-2 therapy had no clinical benefit as shown in the ESPRIT and SILCAAT trials. We focused on subgroups of patients defined according to CD4 cell counts at baseline and over time to assess the threshold above which IL-2 therapy was no longer beneficial in a large cohort of HIV-1 infected patients. Methods Within the French Hospital Database on HIV, a total of 953 IL-2-treated patients were compared with 27 750 IL-2-untreated patients, matched for the date of enrolment, sex, age, and the baseline CD4 cell count and plasma HIV-1 RNA level. The risk of clinical progression, defined as the occurrence of a new AIDS-defining event or death, was studied with multivariable Cox proportional hazards models and Poisson regression models. Results We found no clinical benefit in patients starting IL-2 with CD4 count >/=200 cells/mm(3) [hazard ratio (HR) = 1.13; 95% confidence interval (CI), 0.81-1.57], while a benefit was observed in patients with CD4 count <200 cells/mm(3) (HR = 0.64; 95% CI, 0.48-0.86). The observed benefit was due to the risk reduction in the 100-350/mm(3) stratum of updated CD4 cell counts (relative rate = 0.30; 95% CI, 0.09-1.03). Conclusions Higher CD4 cell counts at enrolment and shorter follow-up with low to intermediate CD4 cell counts may explain why IL-2 therapy had no observed clinical benefit in the SILCAAT study. Our findings suggest that the benefit of IL-2 is restricted to a narrow range of CD4 cell counts, arguing against the use of IL-2 in HIV infection to reduce the risk of clinical events.
9: Journal of virology, 2010 Aug 4, 20(16)
Mononucleosis and antigen-driven T cell responses have different requirements for IL-2 signaling in murine gammaherpesvirus infection.
[Abstract]IL-2 has been implicated as being necessary for the optimal formation of primary CD8(+) T cell responses against various pathogens. Here, we have examined the role that IL-2 signaling plays in several aspects of a CD8(+) T cell response against murine gammaherpesvirus (MHV-68). Exposure to MHV-68 causes a persistent infection along with infectious mononucleosis, providing a model to study these processes in mice. Our study indicates that CD25 is necessary for optimal expansion of the antigen-specific CD8(+) T cell response, but not for the long-term memory response. Contrastingly, IL-2 signaling through CD25 is absolutely required for CD8(+) T cell mononucleosis.
10: Journal of immunotherapy (Hagerstown, Md. : 1997), 2010 Jul 20, 148(2-3)
Prevention of Interleukin-2 Withdrawal-Induced Apoptosis in Lymphocytes Retrovirally Cotransduced With Genes Encoding an Antitumor T-cell Receptor and an Antiapoptotic Protein.
[Abstract]Adoptive cell transfer using autologous tumor infiltrating lymphocytes or lymphocytes transduced with antitumor T-cell receptor (TCR) is an effective therapy for patients with metastatic melanoma. A limiting factor in the effectiveness of this treatment is the apoptosis of the transferred cells when Interleukin-2 (IL-2) administration is withdrawn. In an attempt to improve persistence of the transferred lymphocytes, we cotransduced human peripheral blood lymphocytes with retroviruses encoding Bcl-2 or Bcl-xL, antiapoptotic genes of the BCL2 family, and the MART-1 melanoma tumor antigen-specific TCR, DMF5. Lymphocytes were cotransduced with 38% to 64% cotransduction efficiency, and exhibited a marked delay in apoptosis after IL-2 withdrawal. Cotransduction with Bcl-2 or Bcl-xL did not affect cytokine secretion or lytic ability of the DMF5-transduced lymphocytes. After 5 days of IL-2 withdrawal, cotransduced lymphocytes produced similar levels of IFN-gamma per cell as DMF5-alone transduced lymphocytes in response to tumor cells. Cotransduction did not alter the phenotype of lymphocytes with respect to a panel of T-cell differentiation markers. In a mouse model of melanoma, adoptively transferred T cells transduced with Bcl-2 persisted better in vivo at the site of tumor, 13 and 21 days after adoptive transfer (P=0.0064 and 0.041, respectively), with evidence of enrichment of the Bcl-2-transduced population over time (P<0.0001). Thus, by coexpressing Bcl-2 or Bcl-xL with a tumor-specific TCR, we have engineered a lymphocyte that resists apoptosis owing to IL-2 withdrawal without altering its tumor-specific function or phenotype, and thus may show improved antitumor effectiveness in vivo after cell transfer.
11: Journal of immunotherapy (Hagerstown, Md. : 1997), 2010 Jul 20, 148(2-3)
Cord Blood Natural Killer Cells Exhibit Impaired Lytic Immunological Synapse Formation That Is Reversed With IL-2 Exvivo Expansion.
[Abstract]Peripheral blood natural killer (NK) cell therapy for acute myeloid leukemia has shown promise in clinical trials after allogeneic stem cell transplantation. Cord blood (CB) is another potentially rich source of NK cells for adoptive immune therapy after stem cell transplantation. Tightly regulated receptor signaling between NK cells and susceptible tumor cells is essential for NK cell-mediated cytotoxicity. However, despite expressing normal surface activating and inhibitory NK receptors, CB-derived NK cells have poor cytolytic activity. In this study, we investigate the cellular mechanism and demonstrate that unmanipulated CB-NK cells exhibit an impaired ability to form F-actin immunologic synapses with target leukemia cells compared with peripheral blood-derived NK cells. In addition, there was reduced recruitment of the activating receptor CD2, integrin leukocyte function-associated antigen-1, and the cytolytic molecule perforin to the CB-NK synapse site. Exvivo interleukin (IL)-2 expansion of CB-NK cells enhanced lytic synapse formation including CD2 and leukocyte function-associated antigen-1 polarization and activity. Furthermore, the acquired antileukemic function of IL-2-expanded CB-NK cells was validated using a nonobese diabetic severe combined immunodeficient IL-2 receptor common gamma-chain null mouse model. We believe our results provide important mechanistic insights for the potential use of IL-2-expanded CB-derived NK cells for adoptive immune therapy in leukemia.
12: Journal of immunotherapy (Hagerstown, Md. : 1997), 2010 Jul 20, 148(2-3)
A Pilot Study of Denileukin Diftitox (DD) in Combination With High-dose Interleukin-2 (IL-2) for Patients With Metastatic Renal Cell Carcinoma (RCC).
[Abstract]High-dose (HD) IL-2 is approved to treat renal cell carcinoma (RCC) with modest response rates and significant toxicity. Enhancement of cytotoxic T-cell activity by IL-2 is 1 mechanism of action. IL-2 also stimulates regulatory T lymphocytes (Tregs), which are associated with poor prognosis. Favorable outcomes are associated with greater rebound absolute lymphocyte count (Fumagalli 2003). DD depletes IL-2 receptor (CD25 component) expressing cells. We hypothesized that sequential therapy could complement each other; DD would deplete Tregs so IL-2 could more effectively stimulate proliferation and activity of cytotoxic T lymphocytes. Patients (n=18) received standard HD IL-2 and 1 dose of DD daily for 3 days; periodic flow cytometry and complete blood counts were performed. Group A included 3 patients to assess safety only with DD 6 mug/kg between the IL-2 courses. Group B included 9 patients at 9 mug/kg DD before the IL-2 courses. Group C included 6 patients at 9 mug/kg DD between the IL-2 courses. Efficacy using the RECIST criteria was assessed after the treatment. Fifteen patients from a study of IL-2 without DD served as controls for toxicity comparison and 13 of these for flow cytometry comparisons. No unusual toxicity was noted. For group B/C patients receiving DD, the median decline in Tregs was 56.3% from pre-DD to post-DD (P=0.013). Peak absolute lymphocyte count change from baseline was +9980/muL for group B, +4470/muL for group C, and +4720/muL for the controls (P=0.005 B vs. C). The overall response rate was 5 of 15 (33%); 3 of 9 (33%) and 2 of 6 (33%) for groups B and C, respectively, including 2 patients with sarcomatoid RCC and 1 with earlier sunitinib therapy.
13: Toxicology and applied pharmacology, 2010 Jul 23, 140(8)
Organophosphorous Pesticide Metabolite (DEDTP) Induces Changes in the Activation Status of Human Lymphocytes by Modulating the Interleukin 2 Receptor Signal Transduction Pathway.
[Abstract]Diethyldithiophosphate (DEDTP) is a metabolite formed by biotransformation of organophosphorous (OP) compounds that has a longer half-life than its parental compound. Here we evaluate the effects of DEDTP on human CD4+ T lymphocytes. In vitro exposure to DEDTP (1-50muM) decreased [(3)H]-thymidine incorporation in resting cells and increased CD25 surface expression without altering cell viability. DEDTP treatment inhibited anti-CD3/anti-CD28 stimulation-induced CD4+ and CD8+ T cell proliferation determined by CFSE dilution. Decreased CD25 expression and intracellular IL-2 levels were correlated with this defect in cell proliferation. IL-2, IFN-gamma and IL-10 secretion were also reduced while IL-4 secretion was not altered. Increased phosphorylation of SOCS3 and dephosphorylation of STAT5 were induced by DEDTP after as little as 5min of exposure. In addition, DEDTP induced phosphorylation of ERK, JNK and p38 and NFAT nuclear translocation. These results suggest that DEDTP can modulate phosphorylation of intracellular proteins such as SOCS3, which functions as a negative regulator of cytokine signalling, and that DEDTP exposure may thus cause T cells to fail to respond to further antigen challenges.
14: PloS one, 2010, 5(7)
Potential Role for IL-2 ELISpot in Differentiating Recent and Remote Infection in Tuberculosis Contact Tracing.
[Abstract]Interferon (IFN)-gamma release assays (IGRA) have improved tuberculosis contact tracing, but discrimination of recent from remote Mycobacterium tuberculosis contacts is not possible by IGRA alone. We present results of a tuberculosis contact investigation with a new early-secretory-antigenic-target (ESAT)-6 and culture-filtrate-protein (CFP)-10 specific interleukin (IL)-2 ELISpot in addition to ESAT-6 and CFP-10 specific IFN-gamma ELISpot and tuberculin skin testing (TST). Results of the TST, IFN-gamma ELISpot and IL-2 ELISpot were positive in 6/172 (3.4%), 7/167 (4.2%) and 6/196 (3.1%) of contacts, respectively. Close contact (>/=100 hours) to the index case increased the risk of positive results in the IFN-gamma ELISpot, TST, and IL-2 ELISpot by 40.8, 19.3, and 2.5 times, respectively. Individuals with a positive IFN-gamma ELISpot/negative IL-2 ELISpot result had a median (IQR) duration of index case exposure of 568 hours (133_1000) compared to individuals with a positive IFN-gamma ELISpot/positive IL-2 ELISpot result (median = 24 hours; 20_130; p-value = 0.047). Combination of a M. tuberculosis specific IFN-gamma ELISpot with a M. tuberculosis specific IL-2 ELISpot significantly improved the identification of individuals with the highest risk of recent M. tuberculosis infection and is a promising method that should be explored to target tuberculosis preventive chemotherapy.
15: British journal of haematology, 2010 Jul 9, 185(2)
IL1RN VNTR and IL2-330 polymorphic genes are independently associated with chronic immune thrombocytopenia.
[Abstract]Summary Chronic Immune Thrombocytopenia (cITP) is an acquired immune-mediated disease associated with a T-helper cell type 1 (Th1) immune polarization, whose genetic risk factors, however, are largely unknown. We investigated polymorphisms in promoter regions of genes that code molecules involved in proinflammatory immune response [IL1B-31T/C, IL1RN variable number tandem repeats (VNTR), IL2-330T/G, and TNF-307G/A] as well as in genes that code Toll like receptors (TLR) (TLR2 Arg753Gln, TLR4 Asp299Gly and TLR5 Arg(392stop)) in 122 patients with cITP and 541 blood donors. The frequencies of the IL1RN polymorphic allele 2 (P = 0.001) and of the IL2-330 polymorphic allele G (P = 0.004) were significantly higher in cITP patients than in blood donors. In logistic analysis adjusting for age and gender, the polymorphisms remained independently associated with cITP. Enhanced serum concentrations of interleukin (IL)-1alpha and IL-1beta were observed in cITP (P < 10(-3)) and blood donor (P = 0.04) carriers of the IL1RN*2. Also, the serum levels of IL-2 and gamma-interferon (IFN-gamma) were increased in cITP patients (P < 10(-3) and P = 0.04 respectively) and blood donors (P < 10(-3) and P = 0.03 respectively) harbouring the IL2-330G allele. Here we demonstrated that IL2-330G and IL1RN*2 are independently associated with cITP and are functional in vivo, which strongly suggests that they contribute to the pathogenesis of cITP.
16: European journal of immunology, 2010 Jul 7, 185(2)
IL-2 is positively involved in the development of colitogenic CD4(+) IL-7Ralpha(high) memory T cells in chronic colitis.
[Abstract]IL-2 and IL-7 share a common gamma-chain receptor and are critical for T-cell homeostasis. We aim to clarify the reciprocal roles of IL-2 and IL-7 in the development and persistence of chronic colitis. We performed a series of adoptive transfers of IL-2(-/-) CD4(+)CD45RB(high) T cells into RAG-2(-/-) mice and assessed the role of IL-2 in the induction of IL-7Ralpha on colitogenic CD4(+) T cells and the development of chronic colitis. RAG-2(-/-) mice transferred with WT but not with IL-2(-/-) CD4(+)CD45RB(high) T cells developed Th1/Th17-mediated colitis. Consistently, re-expression of IL-7Ralpha was severely impaired on IL-2(-/-) but not on WT CD4(+) T cells from the transferred mice. To exclude a contribution of the preclinical autoimmunity of IL-2(-/-)mice, WT Ly5.1(+) or IL-2(-/-) Ly5.2(+) CD4(+)CD45RB(high) T cells from GFP mice previously transplanted with the same number of WT and IL-2(-/-) BM cells were transferred into RAG-2(-/-) mice. RAG-2(-/-) mice transferred with IL-2(-/-)-derived CD4(+)CD45RB(high) T cells did not develop colitis, but their splenic CD4(+) T cells changed from effector-memory to central-memory type. These results show that IL-2 is critically involved in the establishment and maintenance of IL-7-dependent colitogenic memory CD4(+)IL-7Ralpha(high) T cells.
17: Bioorganic & medicinal chemistry letters, 2010 Aug 15, 20(16)
Structure-activity relationship of lupane-triterpene glycosides from Acanthopanax koreanum on spleen lymphocyte IL-2 and IFN-gamma.
[Abstract]Phytochemical investigation resulted in the isolation of three new lupane-triterpene glycosides acankoreosides M-O (1, 2 and 8) together with eight known lupane-triterpene glycosides (3-7, 9-11) from the leaves of Acanthopanax koreanum (Araliaceae). Their chemical structures were elucidated by mass, 1D and 2D NMR spectroscopy. The effect of eleven lupane-triterpene glycosides on Con A-induced splenolytic production of IL-2 and IFN-gamma were measured as markers of acquired immune responses. Compounds 4, 5, 7, and 11 (5, 25, and 100muM) significantly increased IFN-gamma and IL-2 release in spleen cells.
18: Scandinavian journal of immunology, 2010 Jul, 72(1)
Kinetics of Local Tissue and Regional Lymph Node IL-2 and IFN-gamma Responses in Experimental Oral Mucosa and Skin Contact Sensitivity in Mice.
[Abstract]Abstract Using ELISA, we have quantified the levels of IL-2 and IFN-gamma in the oral mucosa, ear skin and regional and distant lymph nodes in an experimental murine model of contact sensitivity (CS), induced by the hapten oxazolone (OXA). Compared to normal conditions, the levels of IL-2 peaked early (4-6 h) after hapten exposure in the hapten-exposed tissues analysed both during the first hapten exposure (sensitization) and the second (elicitation) phase, thereafter quickly to subside. The oral mucosa displayed maximal 24-fold increase in IL-2 levels after sensitization and 39-fold increase after elicitation. Respective figures for ear skin were x27 and x35 and for regional lymph nodes x8 and x9, respectively. The distant lymph nodes displayed only minor cytokine increases at any time. IFN-gamma-levels did not increase after sensitization with OXA. An increase in IFN-gamma was seen after the second exposure, peaking at 8-24 h, thereafter quickly subsiding. The oral mucosa IFN-gamma increased x14 after elicitation, the ear skin x8 and regional lymph nodes x37. The weight of the four regional lymph nodes increased from 10 to 38 mg, and the total number of cells in these lymph nodes was increased x11, peaking 48 h after the elicitation. We conclude that in CS reactions, tissue levels of IL-2 increased in buccal mucosa, ear skin and in regional lymph nodes after hapten exposure and re-exposure, IFN-gamma appeared only after re-exposure to the hapten. The increased weight of the regional lymph nodes was mainly attributed to cell proliferation. The common ectodermal origin and the similarity of the CS reactions on skin and in buccal mucosa indicate that these tissues share common immunological patterns of Th1 cell reactivity, at least in dealing with haptens like OXA.
19: Cancer prevention research (Philadelphia, Pa.), 2010 Jun 29, 72(1)
Serum Cytokine Analysis in a Positive Chemoprevention Trial: Selenium, Interleukin-2, and an Association with Squamous Preneoplastic Disease.
[Abstract]This study represents a multiplex cytokine analysis of serum from a 10-month randomized, controlled trial of 238 subjects that investigated the effects of selenomethionine and/or celecoxib in subjects with mild or moderate esophageal squamous dysplasia. The original chemoprevention study found that, among those with mild dysplasia, selenomethionine treatment favorably altered dysplasia grade. The current analysis found that selenomethionine downregulated interleukin (IL)-2 by 9% (P = 0.04), whereas celecoxib downregulated IL-7 by 11% (P = 0.006) and upregulated IL-13 by 17% (P = 0.008). In addition, an increase in IL-7 tertile from baseline to t10 was significantly associated with an increase in dysplasia grade, both overall [odds ratio (OR), 1.47; P = 0.03] and among those with mild dysplasia at t0 (OR, 2.53; P = 0.001). An increase in IL-2 tertile from baseline to t10 was also nonsignificantly associated with worsening dysplasia for all participants (OR, 1.32; P = 0.098) and significantly associated with worsening dysplasia among those with mild dysplasia at baseline (OR, 2.0; P = 0.01). The association of increased IL-2 with worsening dysplasia remained significant in those on selenomethionine treatment who began the trial with mild dysplasia (OR, 2.52; P = 0.03). The current study shows that selenomethionine supplementation decreased serum IL-2 levels, whereas celecoxib treatment decreased IL-7 levels and increased IL-13 levels during a 10-month randomized chemoprevention trial. An increase in IL-2 or IL-7 was associated with increased severity of dysplasia over the course of the trial, especially in those who began the trial with mild dysplasia. The favorable effect of selenomethionine on esophageal dysplasia in the original trial may have been mediated in part by its effect in reducing the levels of IL-2. Cancer Prev Res; 3(7); 810-7. (c)2010 AACR.
20: The Journal of investigative dermatology, 2010 Jun 24, 51(7)
Gene Regulation by 1,25-Dihydroxyvitamin D(3) in CD4+CD25+ Cells Is Enabled by IL-2.
[Abstract]Vitamin D may be responsible for reducing the development and severity of autoimmune and allergic diseases. Topically applied 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) enhances the immunoregulatory ability of CD4+CD25+ T cells residing in the skin-draining lymph nodes (SDLNs) of mice. The mechanisms responsible were investigated by examining the expression of 84 cytokine and cytokine-related genes in a 96-well gene array. CD4+CD25+ cells isolated from the SDLNs of BALB/c mice, 24 and 96 hours after topical treatment with 1,25(OH)(2)D(3), consistently expressed increased IL-2 mRNA levels and also secreted enhanced quantities of IL-2 after ex vivo stimulation with phorbol 12-myristate 13-acetate and ionomycin. CD4+CD25+ cells from the lymph nodes of naive mice constitutively express the vitamin D receptor, allowing direct modulation by 1,25(OH)(2)D(3). However, in vitro treatment with 1,25(OH)(2)D(3) did not modify the expression of 84 tested cytokine and cytokine-related mRNAs. It was only in the presence of IL-2 that 1,25(OH)(2)D(3) increased the expression of genes including IL-2 and TLR4. Further, 1,25(OH)(2)D(3) enhanced the ability of IL-2 to stimulate CD4+CD25+ cells to proliferate in vitro and also regulate contact hypersensitivity responses on adoptive transfer into naive mice. Therefore, 1,25(OH)(2)D(3) enabled by IL-2 can directly enhance the regulatory potential of CD4+CD25+ T cells to control immune disease.Journal of Investigative Dermatology advance online publication, 24 June 2010; doi:10.1038/jid.2010.167.
21: Chemical biology & drug design, 2010 Aug, 76(2)
Crystal Structures of IL-2-inducible T cell Kinase Complexed with Inhibitors: Insights into Rational Drug Design and Activity Regulation.
[Abstract]IL-2-inducible T cell kinase plays an essential role in T cell receptor signaling and is considered a drug target for the treatment of Th2-mediated inflammatory diseases. By applying high-throughput protein engineering and crystallization, we have determined the X-ray crystal structures of IL-2-inducible T cell kinase in complex with its selective inhibitor BMS-509744 and the broad-spectrum kinase inhibitors sunitinib and RO5191614. Sunitinib uniquely stabilizes IL-2-inducible T cell kinase in the helix C-in conformation by inducing side chain conformational changes in the ATP-binding site. This preference of sunitinib to bind to an active kinase conformation is reflective of its broad-spectrum kinase activity. BMS-509744 uniquely stabilizes the activation loop in a substrate-blocking inactive conformation, indicating that structural changes described for Src family kinases are also involved in the regulation of IL-2-inducible T cell kinase activity. The observed BMS-509744 binding mode allows rationalization of structure-activity relationships reported for this inhibitor class and facilitates further structure-based drug design. Sequence-based analysis of this binding mode provides guidance for the rational design of inhibitor selectivity.
22: Journal of immunology (Baltimore, Md. : 1950), 2010 Jul 15, 185(2)
An IL-2 Paradox: Blocking CD25 on T Cells Induces IL-2-Driven Activation of CD56bright NK Cells.
[Abstract]Daclizumab (Dac), an Ab against the IL-2R alpha-chain, inhibits brain inflammation in patients with multiple sclerosis, while expanding CD56(bright) immunoregulatory NK cells in vivo. We hypothesized that this unexpected expansion is paradoxically IL-2 driven; caused by the increased availability of T cell-derived IL-2 for NK cell signaling. To this end, we performed ex vivo functional analyses of CD56(bright) NK cells and T cells from patients in clinical trials with Dac. We developed in vitro models to investigate mechanisms for ex vivo observations. We observed that Dac treatment caused decreased numbers and proliferation of FoxP3(+) T regulatory cells (Tregs), a model T cell population known to be dependent on IL-2 for proliferation and survival. As anticipated, Dac therapy inhibited IL-2 signaling in all T cells; however, we also observed functional adaptation of T cells to low IL-2 signal in vivo, characterized by the concomitant enhancement of IL-7 signaling on all T cells and parallel increase of CD127 expression by Tregs. In contrast, IL-2 signaling on CD56(bright) NK cells was not inhibited by Dac and their in vivo proliferation and cytotoxicity actually increased. Mechanistic studies indicated that the activation of CD56(bright) NK cells was likely IL-2 driven, as low doses of IL-2, but not IL-15, mimicked this activation in vitro. Our study provides insight into the role that IL-2 and CD25 play in functional regulation of two important immunoregulatory cell populations in humans: FoxP3(+) Tregs and CD56(bright) NK cells.
23: Neuroscience letters, 2010 Aug 16, 480(2)
Interleukin-2 as a neuromodulator possibly implicated in the physiopathology of sudden infant death syndrome.
[Abstract]Dysfunction in vital brainstem centers, including those controlling cardiorespiratory- and sleep/arousal pathophysiology, is reported in sudden infant death syndrome (SIDS). Biological mechanisms underlying SIDS, however, remain unclear. Cytokines are inter-cellular signaling chemicals. They can interact with neurotransmitters and might thus modify neural and neuroimmune functions. Cytokines could therefore act as neuromodulators. Interleukin (IL)-2 is a major immune-related cytokine. It has not been previously depicted in vital brainstem centers. We detected intense neuronal IL-2 immune-reactivity in the SIDS brainstem, namely in vital neural centers. This IL-2 overexpression might interfere with neurotransmitters in those critical brainstem centers, causing disturbed homeostatic control of cardiorespiratory and arousal responses, possibly leading to SIDS.
24: Biological trace element research, 2010 Jun 8, 184(12)
Effect of Vanadium on the Subset and Proliferation of Peripheral Blood T Cells, and Serum Interleukin-2 Content in Broilers.
[Abstract]The purpose of this 42-day study was to investigate the effects of dietary excess vanadium on immune function by determining changes of the subsets and proliferation function of peripheral blood T cells. Four hundred twenty 1-day-old avian broilers were divided into six groups and fed on a corn-soybean basal diet as control diet or the same diet amended to contain 5, 15, 30, 45, and 60 ppm vanadium supplied as ammonium metavanadate. In comparison with those of the control group, the percentages of CD (3) (+) , CD (3) (+) CD (4) (+) , and CD (3) (+) CD (8) (+) were decreased in 45 and 60 ppm groups from 14 to 42 days of age, and the percentages of CD (3) (+) and CD (3) (+) CD (4) (+) were increased in 5 ppm group at 42 days of age. The CD (4) (+) /CD (8) (+) ratio was increased in 45 and 60 ppm groups at 28 days of age. Meanwhile, the proliferation function of peripheral blood T cell were decreased in 30, 45, and 60 ppm groups from 14 to 42 days of age. Also, the serum interleukin-2 contents were decreased in 45 and 60 ppm groups from 14 to 42 days of age and increased in 5 ppm group at 28 days of age. Histopathologically, hypocellularity appeared in the thymus in 45 and 60 ppm groups. It was concluded that dietary vanadium in excess of 30 ppm reduced the percentages of peripheral blood T-cell subsets and the proliferation function and serum interleukin-2 contents. The cellular immune function was finally impaired in broilers.
25: Journal of translational medicine, 2010 Jun 7, 8(1)
Vaccination with a plasmid DNA encoding HER-2/neu together with low doses of GM-CSF and IL-2 in patients with metastatic breast carcinoma: a pilot clinical trial.
[Abstract]ABSTRACT: BACKGROUND: Adjuvant trastuzumab (Herceptin) treatment of breast cancer patients significantly improves their clinical outcome. Vaccination is an attractive alternative approach to provide HER-2/neu (Her2)-specific antibodies and may in addition concomitantly stimulate Her2-reactive T-cells. Here we report the first administration of a Her2-plasmid DNA (pDNA) vaccine in humans. METHODS: The vaccine, encoding a full-length signaling-deficient version of the oncogene Her2, was administered together with low doses of GM-CSF and IL-2 to patients with metastatic Her2-expressing breast carcinoma who were also treated with trastuzumab. Six of eight enrolled patients completed all three vaccine cycles. In the remaining two patients treatment was discontinued after one vaccine cycle due to rapid tumor progression or disease-related complications. The primary objective was the evaluation of safety and tolerability of the vaccine regimen. As a secondary objective, treatment-induced Her2-specific immunity was monitored by measuring antibody production as well as T-cell proliferation and cytokine production in response to Her2-derived antigens. RESULTS: No clinical manifestations of acute toxicity, autoimmunity or cardiotoxicity were observed after administration of Her2-pDNA in combination with GM-CSF, IL-2 and trastuzumab. No specific T-cell proliferation following in vitro stimulation of freshly isolated PBMC with recombinant human Her2 protein was induced by the vaccination. Immediately after all three cycles of vaccination no or even decreased CD4+ T-cell responses towards Her2-derived peptide epitopes were observed, but a significant increase of MHC class II restricted T-cell responses to Her2 was detected at long term follow-up. Since concurrent trastuzumab therapy was permitted, lambda-subclass specific ELISAs were performed to specifically measure endogenous antibody production without interference by trastuzumab. Her2-pDNA vaccination induced and boosted Her2-specific antibodies that could be detected for several years after the last vaccine administration in a subgroup of patients. CONCLUSION: This pilot clinical trial demonstrates that Her2-pDNA vaccination in conjunction with GM-CSF and IL-2 administration is safe, well tolerated and can induce long-lasting cellular and humoral immune responses against Her2 in patients with advanced breast cancer. Trial registration: The trial registration number at the Swedish Medical Products Agency for this trial is Dnr151:785/2001.
26: Protein and peptide letters, 2010 Jun 3, 70(9)
Expression, Purification, and Characterization of a Functional Mutant Recombinant Human Interleukin-2.
[Abstract]In the current study, a mutant recombinant human interleukin-2 (MhIL-2) was generated using site-directed mutagenesis. The bacteria transformed with plasmid pET15b-MhIL-2 were cultured in LB medium containing 0.6mM IPTG for 8 hours at 27 degrees C. Approximately 90% of His-MhIL-2 was efficiently expressed in soluble form. Purification efficiency was optimized using a number of strategies, including nickel ion chelating chromatography, desalting chromatography, thrombin cleavage and Superdex 75 gel filtration chromatography. The final product had >95% purity. PBMCs, CD4+ and CD8+ T cell proliferation assays revealed that one such mutant has identical functional property to the wild-type hIL-2. In summary, we generated a mutant hIL-2 that is functionally identical to wild-type hIL-2.
27: Drugs, 2010 Jun 18, 70(9)
Role of Interleukin-2 in Patients with HIV Infection.
[Abstract]Control of viral replication to below the level of quantification using combination antiretroviral therapy (ART) [cART] has led to a dramatic fall in mortality and morbidity from AIDS. However, despite the success of cART, it has become apparent that many patients do not achieve normalized CD4+ T-cell counts despite virological suppression to below the level of quantification (<50 copies/mL). Increasing data from cohort studies and limited data from clinical trials, such as the SMART study, have shown that higher CD4+ T-cell counts are associated with reductions in morbidity and mortality from both AIDS and serious non-AIDS (SNA) conditions, including cardiovascular disease. Enhancement of immune restoration over and above that achievable with ART alone, using a number of strategies including cytokine therapy, has been of interest for many years. The most studied cytokine in this setting is recombinant interleukin (IL)-2 (rIL-2). The purpose of this review is to describe the current status of rIL-2 as a therapeutic agent in the treatment of HIV-1 infection. The review focuses on the rationale underpinning the exploration of rIL-2 in HIV infection, summarizing the phase II and III findings of rIL-2 as an adjunctive therapy to ART and the phase II studies of rIL-2 as an antiretroviral-sparing agent. The phase II studies demonstrated the potential utility of continuous intravenous IL-2 and subsequently intermittent dosing with subcutaneous rIL-2 as a cytokine that could expand the CD4+ T-cell pool in HIV-1-infected patients without any significant detrimental effect on HIV viral load and with an acceptable adverse-effect profile. These data were utilized in designing the phase II studies of rIL-2 as an ART-sparing agent and, more importantly, the large phase III clinical endpoint studies of rIL-2 in HIV-1-infected adults, ESPRIT and SILCAAT. In the latter, subcutaneous rIL-2 was given intermittently (5 days of twice-daily dosing at 4.5-7.5 million international units per dose every 8 weeks) to HIV-1-infected adults receiving cART using an induction/maintenance strategy. Both studies explored the clinical benefit of intermittent subcutaneous rIL-2 with cART versus cART in HIV-infected adults with CD4+ T-cell counts >/=300 cells/muL (ESPRIT study) and 50-299 cells/muL (SILCAAT study). Both studies showed that receipt of rIL-2 conferred no clinical benefit despite a significantly higher CD4+ T-cell count in the rIL-2 arms of both studies. Moreover, there was an excess of grade 4 clinical events in ESPRIT rIL-2 recipients. The results of the phase III clinical endpoint studies showed that rIL-2 has no place as a therapeutic agent in the treatment of HIV infection.
28: Arthritis and rheumatism, 2010 Aug, 62(8)
The clinical significance of decreased T cell interleukin-2 production in systemic lupus erythematosus: Connecting historical dots.
[Abstract]Regulatory T cells (T reg cells) play a major role in controlling the pathogenic autoimmune process in type 1 diabetes (T1D). Interleukin 2 (IL-2), a cytokine which promotes T reg cell survival and function, may thus have therapeutic efficacy in T1D. We show that 5 d of low-dose IL-2 administration starting at the time of T1D onset can reverse established disease in NOD (nonobese diabetic) mice, with long-lasting effects. Low-dose IL-2 increases the number of T reg cells in the pancreas and induces expression of T reg cell-associated proteins including Foxp3, CD25, CTLA-4, ICOS (inducible T cell costimulator), and GITR (glucocorticoid-induced TNF receptor) in these cells. Treatment also suppresses interferon gamma production by pancreas-infiltrating T cells. Transcriptome analyses show that low-dose IL-2 exerts much greater influence on gene expression of T reg cells than effector T cells (T eff cells), suggesting that nonspecific activation of pathogenic T eff cells is less likely. We provide the first preclinical data showing that low-dose IL-2 can reverse established T1D, suggesting that this treatment merits evaluation in patients with T1D.
29: Arthritis and rheumatism, 2010 Aug, 62(8)
Reversing interleukin-2 inhibition mediated by anti-double-stranded DNA autoantibody ameliorates glomerulonephritis in MRL-lpr/lpr mice.
[Abstract]OBJECTIVE: Our previous study demonstrated that anti-double-stranded DNA (anti-dsDNA) antibodies involved in lupus nephritis down-regulate the production of interleukin-2 (IL-2) in T cells, which in turn, contributes to the defective production of cytotoxic cells and to activation-induced cell death in vitro. To reveal novel molecular targets for lupus therapy, the molecular mechanisms of IL-2 down-regulation by anti-dsDNA were studied. METHODS: Anti-dsDNA monoclonal antibody (mAb) 9D7 was used to study the molecular mechanisms of IL-2 production in vitro. Treatment with arginine-rich peptide, a penetration inhibitor, was used to verify the effect of internalization of anti-dsDNA on the production of IL-2. The signaling pathway for IL-2 expression induced by anti-dsDNA was analyzed by using kinase inhibitors. The therapeutic effects of these inhibitors were evaluated in MRL-lpr/lpr mice. RESULTS: Inhibition of IL-2 production in activated Jurkat cells and human T cells pretreated with mAb 9D7 was reversed by treatment with the arginine-rich peptide. Levels of pAkt and phosphorylated glycogen synthase kinase 3 (pGSK-3) were reduced in activated Jurkat cells that had been pretreated with mAb 9D7. The inhibition of IL-2 production by mAb 9D7 was counteracted by pretreating the cells with LiCl (a GSK-3 inhibitor). However, IL-2 reduction was not recovered in the cells pretreated with ERK and JNK inhibitors. Furthermore, MRL-lpr/lpr mice injected with LiCl or with arginine-rich peptide restored the IL-2 production and reduced the manifestations of lupus. CONCLUSION: These findings suggest that penetration of T cells by anti-dsDNA may inhibit IL-2 production by activating GSK-3. Moreover, blocking GSK-3 activation as well as inhibiting anti-dsDNA penetration is a potential therapeutic approach for lupus.
30: Cancer immunology, immunotherapy : CII, 2010 May 20, 285(21)
Endostatin gene therapy enhances the efficacy of IL-2 in suppressing metastatic renal cell carcinoma in mice.
[Abstract]We investigated whether the administration of IL-2 combined with endostatin gene therapy was able to produce additive or even synergistic immunomodulatory activity in a mouse model of metastatic renal carcinoma. Renca cells were injected into the tail vein of BALB/c mice. After 24 h, the animals were randomly divided into four groups (5 mice/group). One group of mice was the control, the second group received treatment with 100,000 UI of Recombinant IL-2 (Proleukin, Chiron) twice a day, 1 day per week during 2 weeks (IL-2), the third group received treatment with a subcutaneous inoculation of 3.6 x 10(6) endostatin-producing cells, and the fourth group received both therapies (IL-2 + ES). Mice were treated for 2 weeks. In the survival studies, 10 mice/group daily, mice were monitored daily until they died. The presence of metastases led to a twofold increase in endostatin levels. Subcutaneous inoculation of NIH/3T3-LendSN cells resulted in a 2.75 and 2.78-fold increase in endostatin levels in the ES and IL-2 + ES group, respectively. At the end of the study, there was a significant decrease in lung wet weight, lung nodules area, and microvascular area (MVA) in all treated groups compared with the control group (P < 0.001). The significant difference in lung wet weight and lung nodules area between groups IL-2 and IL-2 + ES revealed a synergistic antitumor effect of the combined treatment (P < 0.05). The IL-2 + ES therapy Kaplan-Meier survival curves showed that the probability of survival was significantly higher for mice treated with the combined therapy (log-rank test, P = 0.0028). Conjugated therapy caused an increase in the infiltration of CD4, CD8 and CD49b lymphocytes. An increase in the amount of CD8 cells (P < 0.01) was observed when animals received both ES and IL-2, suggesting an additive effect of ES over IL-2 treatment. A synergistic effect of ES on the infiltration of CD4 (P < 0.001) and CD49b cells (P < 0.01) was also observed over the effect of IL-2. Here, we show that ES led to an increase in CD4 T helper cells as well as cytotoxic lymphocytes, such as NK cells and CD8 cells, within tumors of IL-2 treated mice. This means that ES plays a role in supporting the actions of T cells.
31: The American journal of clinical nutrition, 2010 May 19, 285(21)
IL-2 and IL-10 gene polymorphisms are associated with respiratory tract infection and may modulate the effect of vitamin E on lower respiratory tract infections in elderly nursing home residents.
[Abstract]BACKGROUND: Vitamin E supplementation may be a potential strategy to prevent respiratory tract infections (RIs) in the elderly. The efficacy of vitamin E supplementation may depend on individual factors including specific single nucleotide polymorphisms (SNPs) at immunoregulatory genes. OBJECTIVE: We examined whether the effect of vitamin E on RIs in the elderly was dependent on genetic backgrounds as indicated by SNPs at cytokine genes. DESIGN: We used data and DNA from a previous vitamin E intervention study (200 IU vitamin E or a placebo daily for 1 y) in elderly nursing home residents to examine vitamin E-gene interactions for incidence of RI. We determined the genotypes of common SNPs at IL-1beta, IL-2, IL-6, IL-10, TNF-alpha, and IFN-gamma in 500 participants. We used negative binomial regression to analyze the association between genotype and incidence of infection. RESULTS: The effect of vitamin E on lower RI depended on sex and the SNP at IL-10 -819G-->A (P = 0.03 for interaction for lower RI). Furthermore, we observed that subjects with the least prevalent genotypes at IL-2 -330A-->C (P = 0.02 for upper RI), IL-10 -819G-->A (P = 0.08 for upper RI), and IL-10 -1082C-->T (P < 0.001 for lower RI in men) had a lower incidence of RI independent of vitamin E supplementation. CONCLUSIONS: Studies that evaluate the effect of vitamin E on RIs should consider both genetic factors and sex because our results suggest that both may have a significant bearing on the efficacy of vitamin E. Furthermore, common SNPs at cytokine genes may contribute to the individual risk of RIs in the elderly. This trial was registered at clinicaltrials.gov as NCT00758914.
32: Journal of immunology (Baltimore, Md. : 1950), 2010 May 17, 285(21)
Differential Roles of IL-2-Inducible T Cell Kinase-Mediated TCR Signals in Tissue-Specific Localization and Maintenance of Skin Intraepithelial T Cells.
[Abstract]Tissue-specific innate-like gammadelta T cells are important components of the immune system critical for the first line of defense, but mechanisms underlying their tissue-specific development are poorly understood. Our study with prototypical skin-specific intraepithelial gammadeltaT lymphocytes (sIELs) found that among different thymic gammadelta T cell subsets fetal thymic precursors of sIELs specifically acquire a unique skin-homing property after positive selection, suggesting an important role of the TCR selection signaling in "programming" them for tissue-specific development. In this study, we identified IL-2-inducible T cell kinase (ITK) as a critical signal molecule regulating the acquirement of the skin-homing property by the fetal thymic sIEL precursors. In ITK knockout mice, the sIEL precursors could not undergo positive selection-associated upregulation of thymus-exiting and skin-homing molecules sphingosine-1-phosphate receptor 1 and CCR10 and accumulated in the thymus. However, the survival and expansion of sIELs in the skin did not require ITK-transduced TCR signaling, whereas its persistent activation impaired sIEL development by inducing apoptosis. These findings provide insights into molecular mechanisms underlying differential requirements of TCR signaling in peripheral localization and maintenance of the tissue-specific T cells.
33: Journal of immunology (Baltimore, Md. : 1950), 2010 May 14, 285(21)
Distinct Roles for IL-2 and IL-15 in the Differentiation and Survival of CD8+ Effector and Memory T Cells.
[Abstract]IL-2 provides a memory differentiation signal to CD8(+) T cells during the primary response that impacts the ability of the subsequent memory pool to mount a successful recall response. In this study, we find that although primary effector CTL development is modestly decreased in the absence of IL-2, the persistence of short-term and long-term effector memory CD8(+) T cells on pathogen clearance is greatly diminished. Furthermore, secondary challenge of CD8(+) memory T cells lacking the high-avidity IL-2R results in a failure to repopulate the effector pool. The role of IL-2 in promoting effector differentiation is not shared with the highly related cytokine, IL-15. Although IL-15 supports the survival of effector CD8(+) T cells after pathogen clearance, its absence does not impair either primary or secondary effector CTL differentiation, nor does it impact the differentiation of long-term effector memory CD8(+) T cells. These findings indicate a unique role for IL-2, but not IL-15, in promoting the differentiation not only of primary effector CD8(+) T cells, but also of CD8(+) memory T cells capable of secondary effector differentiation.
34: American journal of reproductive immunology (New York, N.Y. : 1989), 2010 May 13, 285(21)
Lipopolysaccharide (LPS)-induced Interferon (IFN)-gamma Production by Decidual Mononuclear Cells (DMNC) is Interleukin (IL)-2 and IL-12 Dependent.
[Abstract]Citation Negishi M, Izumi Y, Aleemuzzaman S, Inaba N, Hayakawa S. Lipopolysaccharide (LPS)-induced interferon (IFN)-gamma production by decidual mononuclear cells (DMNC) is interleukin (IL)-2 and IL-12 dependent. Am J Reprod Immunol 2010 Problem Th1-shifted immune response is believed to be harmful for successful pregnancy because of activation of maternal cytotoxic T lymphocytes and natural killer cells. However, its effects on Toll-like receptor (TLR)-mediated innate immune response are so far unknown and this study has been undertaken to address the issue. Method of study Decidual tissues were obtained from 16 pregnant women undergoing elective termination during the first trimester pregnancy for socioeconomic reasons. Decidual Mononuclear Cells (DMNC) were stimulated with suboptimal doses of IL-2 and IL-12 with/without LPS, considered to be a TLR4 ligand, for 48 hr. Productions of IFN-gamma and tumor necrosis factor (TNF)-alpha in culture supernatant were measured with ELISA. Results (i) IFN-gamma production was induced with LPS alone which was strongly up-regulated in the presence of IL-2 and IL-12. (ii) TNF-alpha was also induced by LPS but was not affected by the presence of IL-2 and IL-12. Conclusion IL-2 and IL-12 up-regulated the production of IFN-gamma in DMNC through increasing their susceptibility to LPS. TNF-alpha production is independent of such a mechanism.
35: Bioorganic & medicinal chemistry, 2010 Jun 15, 18(12)
Synthesis and biological evaluation of novel (4 or 5-aryl)pyrazolyl-indoles as inhibitors of interleukin-2 inducible T-cell kinase (ITK).
[Abstract]Interleukin-2 inducible T-cell kinase (ITK) is one of five kinases that belong to the Tec kinase family that plays an important role in T-cell and mast cell signaling. Various reports point to a role of ITK in the treatment of allergic asthma. For example, it was shown that mice lacking ITK have reduced airway hyperresponsiveness, inflammation and tracheal responses in an allergic asthma model. In this article, we disclose novel ITK inhibitors based on (4 or 5-aryl)pyrazolyl-indole scaffold that were also found to be selective for ITK over other kinases like IRK, CDK2, GSK3ss and PKA.
36: Immunology, 2010 May 11, 634(1-3)
In CD28-costimulated human na?ve CD4 T cells, I-kappaB kinase controls the expression of cell cycle regulatory proteins via interleukin-2-independent mechanisms.
[Abstract]Summary Stimulation of na?ve CD4(+) T cells through engagement of the T-cell receptor (TCR) and the CD28 co-receptor initiates cell proliferation which critically depends on interleukin (IL)-2 secretion and subsequent autocrine signalling via the IL-2 receptor. However, several studies indicate that in CD28-costimulated T cells additional IL-2-independent signals are also required for cell proliferation. In this study, using a neutralizing anti-human IL-2 antibody and two selective, structurally unrelated, cell-permeable I-kappaB kinase (IKK) inhibitors, BMS-345541 and PS-1145, we show that in human na?ve CD4(+) T cells stimulated through a short engagement of the TCR and the CD28 co-receptor, IKK controls the expression of the cell cycle regulatory proteins cyclin D3, cyclin E and cyclin-dependent kinase 2 (CDK2) and the stability of the F-box protein S-phase kinase-associated protein 2 (SKP2) and its co-factor CDC28 protein kinase regulatory subunit 1B (CKS1B), through IL-2-independent mechanisms.
37: Journal of immunotherapy (Hagerstown, Md. : 1997), 2010 May 11, 634(1-3)
Effects of IL-2 on MMP Expression in Freshly Isolated Human NK Cells and the IL-2-independent NK Cell Line YT.
[Abstract]Interleukin-2 is an important activation factor for natural killer (NK) cells but its effect on NK cell matrix metalloproteinases (MMP) production and matrix degradation is less well investigated. We have used freshly isolated human NK cells and the IL-2-independent NK cell line, YT, to investigate the effects of IL-2 stimulation on NK cell invasion of Matrigel and on MMP expression and production. In YT cells, we found opposing early and late effects of IL-2 stimulation with an early (2 h) increase in MMP-9 protein level and enhanced migration in the Matrigel invasion assay and by 30 hours a decreased mRNA expression of MMP-2, MMP-9, MMP-13, MT3-MMP, and MT6-MMP. We also found a preculture period of 48 hours with IL-2 to negatively affect YT cell migration. We furthermore found that freshly isolated human NK cells Matrigel invasion was MMP-dependent and it increased in response to IL-2. Importantly, in freshly isolated human NK cells we did not see a downregulation of MMPs after 24 hours IL-2 stimulation, but instead a significant upregulation of MT6-MMP mRNA. Because of the cellular localisation of MT6-MMP, which ensures a focalized proteolytic activity, and its high expression compared with the other MMPs in freshly isolated human NK cells makes it of interest to study further.
38: Journal of translational medicine, 2010 Apr 28, 8(1)
Three agonist antibodies in combination with high-dose IL-2 eradicate orthotopic kidney cancer in mice.
[Abstract]ABSTRACT: BACKGROUND: Combination immunotherapies can be effective against subcutaneous tumors in mice but the effect against orthotopic malignant disease is less well characterized. In particular, a combination of three agonist antibodies, termed TrimAb, consisting of anti-DR5, anti-CD40 and anti-CD137 has previously been demonstrated to eradicate a large proportion of subcutaneous renal cell carcinoma (Renca) tumors (75% long-term survival), but the effect against orthotopic disease is not known. Purpose: To determine the relative response of orthotopic tumors, we inoculated Renca into the kidney followed by treatment with TrimAb. RESULTS: We found that orthotopic tumors responded much less to treatment (~13% survival), but a significant improvement in survival could be effected through the addition of IL-2 to the treatment regimen (55% survival). All three agonist antibodies and high dose IL-2, 100,000 IU up to six doses were required. CD8+ T cells were also required for optimal anti-tumor responses. Coadministration of IL-2 led to enhanced T cell activity as demonstrated by an increased frequency of IFN-gamma-producing T cells in tumor-draining lymph nodes, which may have contributed to the observed improvement of therapy against kidney tumors. IMPLICATIONS: Responses of subcutaneous tumors to immunotherapy do not necessarily reflect how orthotopic tumors respond. The use of combination immunotherapy stimulating multiple facets of immunity and including cytokine support for T cells can induce effective anti-tumor responses against orthotopic and metastatic tumors.
39: Nature reviews. Immunology, 2010 May, 10(5)
T cell responses: IL-2 overrules tolerogenic liver responses.
[Abstract]Regulatory T cells (Treg) play an important role in the maintenance of immune tolerance and may be one of the obstacles of successful tumor immunotherapy. In this study, we analyzed the impact of administration of dendritic cell (DC) vaccination in combination with low-dose interleukin (IL)-2 in patients with metastatic renal cell carcinoma on the frequency of CD4+CD25highFoxp3+ Treg cells in peripheral blood. We found that the treatment increased the frequency of Treg cells more than 7-fold compared with pretreatment levels (P<0.0001). The frequency of Treg cells decreased when patients had been off IL-2 treatment for only 8 days, but remained higher than pretreatment levels. A functional assay showed that isolated Treg cells were capable of inhibiting proliferation of responder cells. Also, in vitro studies showed that coculture of mature DCs, autologous T cells and IL-2 leads to an increase in the number of Treg cells whereas IL-21 does not stimulate the induction of Treg cells. These findings demonstrate that even low doses of IL-2 in combination with DC vaccination are able to expand CD4+CD25+Foxp3+ Treg cells in vivo in metastatic renal cell carcinoma patients. Further, the results indicate that the IL-2-induced effect on Treg cells is reversible and declines shortly after termination of IL-2 treatment. Our data suggest that approaches combining DC-mediated immunotherapy and depletion of Treg cells may be necessary to enhance the ability of vaccination therapy to elicit effective antitumor responses in cancer patients. Also, adjuvant IL-21 administration may lead to immune enhancement without simultaneous induction of Treg cells.
40: Cancer biotherapy & radiopharmaceuticals, 2010 Apr, 25(2)
Pulse infusion interleukin-2 with famotidine and cyclophosphamide has activity in previously treated metastatic melanoma.
[Abstract]There is no established systemic therapy for patients with stage IV melanoma refractory to prior systemic treatment. Interleukin-2 (IL-2) is capable of inducing T-lymphocyte cytotoxicity against melanoma in vitro and in vivo. Famotidine may enhance the activity of T-cells further by allowing for increased IL-2 internalization by the IL-2 receptor on lymphocytes. Cyclophosphamide may decrease the immunosuppressive effects of regulatory T-cells. Daily short intravenous (i.v.) infusions (pulses) of IL-2 were used to treat 14 patients with metastatic melanoma, all of whom had experienced disease progression despite prior systemic therapy. The patients received 21.6 million IU/m(2) of pulse IL-2 i.v. for 15-30 minutes, preceded by 20 mg of famotidine i.v. (13) patients received 350 mg/m(2) of cyclophosphamide i.v. on day 1 (1 patient did not). Eight (8) patients were treated in an oncology inpatient unit while, most recently, 6 patients have received therapy on an outpatient basis. The cycles were repeated every 3 weeks until disease progression occurred. The patients included 10 males with a median age of 56 (range 31-87) with an Eastern Cooperative Oncology Group performance status of -1 (range 0 - -1). Common metastatice sites included lymph nodes (13), lungs (8), liver (4), and subcutaneous (4). Prior systemic therapy included IL-2 (11), interferon (7), and chemotherapy (7). The median number of cycles the patients underwent was 3 with a range of 1-7. The most common toxic reactions were fever, rigors, nausea/emesis, hypomagnesemia, and hypophosphatemia. One complete response and four partial responses were observed (response rate, 36%; 95% confidence interval: 14%-64%). Responses occurred in the lungs, liver, lymph nodes, and subcutaneous sites. The median response duration was 3.4 months, with a median survival of 8.3 months for the entire group. Six (6) patients remain alive with a median survival of 10.3 months. Pulse IL-2 with famotidine and cyclophosphamide produced activity in previously treated patients with melanoma and may be given on an outpatient basis to selected individuals.
41: Expert opinion on biological therapy, 2010 Apr 26, 52(5-6)
Interleukin-2 receptor blockade with humanized monoclonal antibody for solid organ transplantation.
[Abstract]Importance of the field: Induction therapy has reduced the incidence of acute rejection compared with historical standards. The potency of currently available induction immunosuppression is not without risk and should be carefully considered. Induction with daclizumab, an IL-2 receptor antagonist, has been used safely and effectively for over 10 years across different transplant types. As a result of daclizumab use, transplant centers are able to implement steroid-sparing or calcineurin minimization protocols. Unfortunately, the manufacturing costs have resulted in withdrawal of this agent from the market reducing the options for patients undergoing transplantation. Areas covered in this review: This review will update the reader on recently published daclizumab studies in adult solid organ transplant recipients, focusing on comparative studies with other induction agents. What the reader will gain: This paper will provide a summary of comparative studies between daclizumab and other induction therapies focusing on their efficacy and safety. Take home message: Novel applications, such as long-term use in combination with calcineurin-inhibitor dose reduction and its value in the treatment of acute or chronic rejection have yet to be explored. Since daclizumab has been withdrawn from the market, future IL-2 receptor blockade will have to be achieved with basiliximab, which is a chimeric, monoclonal antibody directed against the same epitope.
42: Clinical and experimental immunology, 2010 Apr 9, 394(3)
Changes in the levels of some acute-phase proteins in human immunodeficiency virus-1 infected patients, following interleukin-2 treatment.
[Abstract]Summary Intermittent interleukin (IL)-2 administration to human immunodeficiency virus (HIV)-1 infected patients is well documented and generally used, but there is limited information about the changes of acute-phase protein (APP) levels in response to this treatment. Fifteen patients undergoing highly active anti-retroviral therapy (HAART) treatment, with undetectable viral load, but low CD4(+) cell count (<300/microl), have been treated with 3.6 M IU Proleukine(R) administered twice daily by subcutaneous injection over 5 days. C-reactive protein (CRP), d-dimer, C3, C9, C1-inh and alpha-2HS glycoprotein levels were measured immediately before IL-2 administration, as well as on day 5 and 2-3 weeks thereafter. After IL-2 administration, both mean d-dimer and CRP levels increased significantly (P < 0.001), but returned (P < 0.001) to baseline within the subsequent 2-3 weeks. Alpha-2HS glycoprotein decreased immediately after IL-2 administration. No significant differences were detected in the levels of C3, C9 and C1-inh. A significant, positive correlation (r = 0.5178, P = 0.0008) was ascertained between the changes of CRP level, measured immediately before as well as 5 days after IL-2 administration, and changes in CD4 T cell counts measured 2-3 weeks before and after treatment, respectively. IL-2 administration induces rapid elevation of two major APPs (CRP, d-dimer). The positive correlation observed between the changes of CRP levels and CD4(+) cell counts after IL-2 administration may indicate that the abrupt, but transitory overproduction of CRP might contribute to the CD4(+) cell count-increasing effect of the drug and/ or may be associated with serious side effects.
43: Biologics : targets & therapy, 2010, 4(6)
Safety and immunogenicity of Salmonella typhimurium expressing C-terminal truncated human IL-2 in a murine model.
[Abstract]Salmonella enterica serovar Typhimurium preferentially colonizes tumors in vivo and has proven to be an effective biologic vector. The attenuated S. enterica Typhimurium strain chi4550 was engineered to express truncated human interleukin-2 and renamed SalpIL2. Previously, we observed that a single oral administration of SalpIL2 reduced tumor number and volume, while significantly increasing local and systemic natural killer (NK) cell populations in an experimental metastasis model. Here we report that in nontumor-bearing mice, a single oral dose of SalpIL2 resulted in increased splenic cytotoxic T and NK cell populations that returned to control levels by 4 weeks post oral administration. Though SalpIL2 was detected in mouse tissues for up to 10 weeks, no prolonged alterations in peripheral blood serum chemistry or complete blood cell counts were observed. Similarly, comparative histopathological analysis of tissues revealed no significant increase in pyogranulomas in SalpIL2-treated animals with respect to saline controls. In Rag-1 knockout mice, which have severely impaired B and T cell function, SalpIL2 reduced growth of hepatic metastases. Furthermore, SalpIL2 altered expression of several proinflammatory cytokines and chemokines in the serum of mice with pulmonary osteosarcoma metastases. These data further suggest that SalpIL2 is avirulent and induces a cell-mediated antitumor response.
44: Journal of drug targeting, 2010 Apr 1, 59(4)
Cationic liposomes bearing IL-2 on their external surface induced mice leukocytes to kill human cervical cancer cells in vitro, and significantly reduced tumor burden in immunodepressed mice.
[Abstract]Tumor cells are known to modify their surroundings in order to escape immunologic detection, and IL-2, a killer cell activator, is one of the factors known to overcome this escape mechanism. In this regard, when we cocultured cells from the human cervical cancer cell line INBL with mice blood leukocytes, no inhibition of tumor cell growth was observed, but when a similar coculture was done in the presence of cationic liposomes bearing IL-2 on their external surface (CL-IL-2), all the INBL cells were killed. In order to evaluate whether this in vitro property of CL-IL-2 to overcome tumor cell detection by lymphocytes could also be reproduced in vivo, INBL cells were intraperitoneally (i.p.) inoculated into immunodepressed mice to produce solid tumors. We observed that the subsequent i.p. delivery of CL-IL-2 rendered the tumor masses significantly smaller. The presence of a large number of infiltrating lymphocytes on those tumors, and the fact that many had a cytotoxic CD8(+) phenotype suggests that these lymphocytes were responsible for the observed antitumor effect. Finally, the possible formation of a bridge between the IL-2R receptors on both, the lymphocytes and the INBL cells, mediated by the IL-2-bearing liposomes, and its possible effect on the activation of antitumor cytotoxic lymphocytes is discussed.
45: European journal of immunology, 2010 Mar 29, 88(4)
Expansion of CD4(+)CD25(+) regulatory T cells via IL-2/anti-IL-2 mAb complexes suppresses experimental autoimmune myasthenia gravis.
[Abstract]Human autoimmune diseases are often characterized by a relative deficiency in CD4(+)CD25(+) regulatory T (Treg) cells. We therefore hypothesized that expansion of Treg cells can ameliorate autoimmune pathology. We tested this hypothesis in an experimental model for autoimmune myasthenia gravis (MG), a B cell-mediated disease characterized by autoantibodies directed against the acetylcholine receptor (AChR) within neuromuscular junctions. We showed that injection of immune complexes composed of the cytokine IL-2 and anti-IL-2 mAbs (JES6-1A12) induced an effective and sustained expansion of Treg cells, via peripheral proliferation of CD4(+)CD25(+)Foxp3(+) cells and peripheral conversion of CD4(+)CD25(-)Foxp3(-) cells. The expanded Treg cells potently suppressed autoreactive T and B cell responses to AChR and attenuated the muscular weakness that is characteristic of MG. Thus, IL-2/anti-IL-2 mAb complexes can expand functional Treg cells in vivo, providing a potential clinical application of this modality for treatment of MG and other autoimmune disorders.
46: Blood, 2010 Mar 29, 88(4)
TRAF6 inhibits Th17 differentiation and TGF-{beta}-mediated suppression of IL-2.
[Abstract]Transforming growth factor-beta (TGF-beta) has an essential role in the generation of inducible regulatory T (iTreg) and Th17 cells. However, little is known about the TGF-beta-triggered pathways that drive the early differentiation of these cell populations. Here we report that CD4(+) T cells lacking the molecular adaptor TNF receptor-associated factor 6 (TRAF6) exhibit a specific increase in Th17 differentiation in vivo and in vitro. We show that TRAF6 deficiency renders T cells more sensitive to TGF-beta-induced Smad2/3 activation and proliferation arrest. Consistent with this, in TRAF6-deficient T cells, TGF-beta more effectively downregulates interleukin (IL)-2, a known inhibitor of Th17 differentiation. Remarkably, TRAF6-deficient cells generate normal numbers of Foxp3-expressing cells in iTreg differentiation conditions where exogenous IL-2 is supplied. These findings reveal an unexpected role for the adaptor molecule TRAF6 in Smad-mediated TGF-beta signaling and Th17 differentiation. Importantly, the data also suggest that a major function of TGF-beta in early Th17 differentiation may be the inhibition of autocrine and paracrine IL-2-mediated suppression of Th17 cell generation.
47: AIDS (London, England), 2010 Mar 27, 24(6)
Prolonged viral suppression without therapy in an HIV-1 seroconverter following early antiretroviral therapy and daily interleukin-2.
[Abstract]Human autoimmune diseases are often characterized by a relative deficiency in CD4(+)CD25(+) regulatory T (Treg) cells. We therefore hypothesized that expansion of Treg cells can ameliorate autoimmune pathology. We tested this hypothesis in an experimental model for autoimmune myasthenia gravis (MG), a B cell-mediated disease characterized by autoantibodies directed against the acetylcholine receptor (AChR) within neuromuscular junctions. We showed that injection of immune complexes composed of the cytokine IL-2 and anti-IL-2 mAbs (JES6-1A12) induced an effective and sustained expansion of Treg cells, via peripheral proliferation of CD4(+)CD25(+)Foxp3(+) cells and peripheral conversion of CD4(+)CD25(-)Foxp3(-) cells. The expanded Treg cells potently suppressed autoreactive T and B cell responses to AChR and attenuated the muscular weakness that is characteristic of MG. Thus, IL-2/anti-IL-2 mAb complexes can expand functional Treg cells in vivo, providing a potential clinical application of this modality for treatment of MG and other autoimmune disorders.
48: Anatomical record (Hoboken, N.J. : 2007), 2010 Mar 11, 59(4)
Interleukin-2 Enhances Dendritic Development and Spinogenesis in Cultured Hippocampal Neurons.
[Abstract]In this study, we investigated the effects of interleukin-2 (IL-2) on dendritic filopodia, dendritic arborization, and spine maturation during the development of cultured rat hippocampal neurons. The cultured hippocampal neurons were transfected with F-GFP (farnesylated enhanced green fluorescent protein) at DIV5 to display the subtle structure of dendrites, and were then treated with IL-2 at various concentrations for different time before living cell image observation. We found that both the dendritic arborization and the length of dendrites per neuron at DIV7, DIV10, and DIV14 were increased under IL-2 treatment in a dose-dependent manner, and the strongest IL-2 effects on both dendritic number and length were observed at DIV7. Also, there was a significant increase in the mobility of dendritic filopodia in neurons at DIV7 treated with 10 ng/mL IL-2 for 48 hr from DIV5. In addition, IL-2 caused an increase in spine density of neurons at DIV14 either treated with IL-2 from DIV5 to DIV7 or from DIV5 to DIV14, but did not affect neurons treated from DIV12 to DIV14. These results indicate that IL-2 affects the dendritic development and spinogenesis of cultured hippocampal neurons, especially during the early developmental stage. Anat Rec, 2010. (c) 2010 Wiley-Liss, Inc.
49: Journal of molecular medicine (Berlin, Germany), 2010 Mar 12, 59(4)
Reciprocal granzyme/perforin-mediated death of human regulatory and responder T cells is regulated by interleukin-2 (IL-2).
[Abstract]Human CD4(+)CD25(high)FOXP3(+) T regulatory cells (Treg) can suppress responder T cell (RC) functions by various mechanisms. In co-cultures of Treg and autologous activated RC, both cell subsets up-regulate the expression of granzymes and perforin, which might contribute to Treg-mediated suppression. Here, we investigate the sensitivity and resistance of Treg and RC to granzyme/perforin-mediated death. CD4(+)CD25(neg) RC were single cell-sorted from the peripheral blood of 25 cancer patients and 15 normal controls. These RC were carboxyfluorescein diacetate succinimidyl ester (CFSE) labeled and co-cultured with autologous CD4(+)CD25(high)FOXP3(+) Treg +/- 150 or +/-1,000 IU/mL of interleukin-2 (IL-2) to evaluate suppression of RC proliferation. In addition, survival of the cells co-cultured for 24 h and 5 days was measured using a flow-based cytotoxicity assay. Freshly isolated Treg and RC expressed granzyme A (GrA), granzyme B (GrB), and perforin. Percentages of positive cells were higher in cancer patients than controls (p < 0.01) and increased upon OKT3 and IL-2 stimulation. Treg, co-cultured with RC at 150 IU/mL of IL-2, no longer expressed cytotoxins and became susceptible to RC-mediated, granzyme/perforin-dependent death. However, in co-cultures with 1,000 IU/mL of IL-2, Treg became resistant to apoptosis and induced GrB-dependent, perforin-independent death of RC. When the GrB inhibitor I or GrB-specific and GrA-specific small inhibitory ribonucleic acids were used to block the granzyme pathway in Treg, RC death, and Treg-mediated suppression of RC, proliferation were significantly inhibited. Human CD4(+)CD25(high) Treg and CD4(+)CD25(neg) RC reciprocally regulate death/growth arrest by differentially utilizing the granzyme-perforin pathway depending on IL-2 concentrations.
50: PLoS pathogens, 2010, 6(3)
Perforin and IL-2 Upregulation Define Qualitative Differences among Highly Functional Virus-Specific Human CD8 T Cells.
[Abstract]The prevailing paradigm of T lymphocyte control of viral replication is that the protective capacity of virus-specific CD8(+) T cells is directly proportional to the number of functions they can perform, with IL-2 production capacity considered critical. Having recently defined rapid perforin upregulation as a novel effector function of antigen-specific CD8(+) T cells, here we sought to determine whether new perforin production is a component of polyfunctional CD8(+) T cell responses that contributes to the control of several human viral infections: cytomegalovirus (CMV), Epstein-Barr virus (EBV), influenza (flu), and adenovirus (Ad). We stimulated normal human donor PBMC with synthetic peptides whose amino acid sequences correspond to defined CTL epitopes in the aforementioned viruses, and then used polychromatic flow cytometry to measure the functional capacity and the phenotype of the responding CD8(+) T cells. While EBV and flu-specific CD8(+) T cells rarely upregulate perforin, CMV-specific cells often do and Ad stimulates an exceptionally strong perforin response. The differential propensity of CD8(+) T cells to produce either IL-2 or perforin is in part related to levels of CD28 and the transcription factor T-bet, as CD8(+) T cells that rapidly upregulate perforin harbor high levels of T-bet and those producing IL-2 express high amounts of CD28. Thus, "polyfunctional" profiling of antigen-specific CD8(+) T cells must not be limited to simply the number of functions the cell can perform, or one particular memory phenotype, but should actually define which combinations of memory markers and functions are relevant in each pathogenic context.
51: PloS one, 2010, 5(2)
Effects of Intermittent IL-2 Alone or with Peri-Cycle Antiretroviral Therapy in Early HIV Infection: The STALWART Study.
[Abstract]BACKGROUND: The Study of Aldesleukin with and without antiretroviral therapy (STALWART) evaluated whether intermittent interleukin-2 (IL-2) alone or with antiretroviral therapy (ART) around IL-2 cycles increased CD4(+) counts compared to no therapy. METHODOLOGY: Participants not on continuous ART with >/=300 CD4(+) cells/mm(3) were randomized to: no treatment; IL-2 for 5 consecutive days every 8 weeks for 3 cycles; or the same IL-2 regimen with 10 days of ART administered around each IL-2 cycle. CD4(+) counts, HIV RNA, and HIV progression events were collected monthly. PRINCIPAL FINDINGS: A total of 267 participants were randomized. At week 32, the mean CD4(+) count was 134 cells greater in the IL-2 alone group (p<0.001), and 133 cells greater in the IL-2 plus ART group (p<0.001) compared to the no therapy group. Twelve participants in the IL-2 groups compared to 1 participant in the group assigned to no therapy experienced an opportunistic event or died (HR 5.84, CI: 0.59 to 43.57; p = 0.009). CONCLUSIONS: IL-2 alone or with peri-cycle HAART increases CD4(+) counts but was associated with a greater number of opportunistic events or deaths compared to no therapy. These results call into question the immunoprotective significance of IL-2-induced CD4(+) cells. TRIAL REGISTRATION: ClinicalTrials.gov NCT00110812.
52: Clinical immunology (Orlando, Fla.), 2010 Feb 23, 159(1)
Interleukin-2-unresponsive immune defects in good syndrome: Letter to the Editor.
[Abstract]Interleukin (IL)-2/IL-2R signalling promotes proliferation and survival of activated T cells and has an essential non-redundant role in the production of regulatory T cells. Associations with different autoimmune diseases of polymorphisms in a linkage disequilibrium block in which the IL2/IL21 genes map (4q27), and also in genes encoding the IL2RA and IL2RB subunits (located in 10p15 and 22q13, respectively), were identified through genome-wide studies. Polymorphisms in these three genes were studied in 430 multiple sclerosis (MS) patients and in 550 ethnically matched controls from Madrid (Spain). Replication and meta-analysis with results from an independent cohort of 771 MS patients and 759 controls from Andaluc¨ªa (Spain) confirmed the association of polymorphisms in the IL2RA gene (P(Mantel-Haenszel,) odds ratio (OR)(M-H) (95% confidence interval, CI) for rs2104286: 0.0001, 0.75 (0.65-0.87); for rs11594656/rs35285258: 0.004, 1.19 (1.06-1.34); for rs41295061: 0.03, 0.77 (0.60-0.98)); showed a trend for association of the IL2/IL21 rs6822844 (P(M-H)=0.07, OR(M-H) (95% CI)=0.86 (0.73-1.01)), but did not corroborate the association for IL2RB. Regression analyses of the combined Spanish cohort revealed the independence of two IL2RA association signals: rs2104286 and rs11594656/rs35285258. The relevant role of the IL2RA gene on MS susceptibility adds support to its common effect on autoimmune risk and the suggestive association of IL2/IL21 warrants further investigation.European Journal of Human Genetics advance online publication, 24 February 2010; doi:10.1038/ejhg.2010.15.
53: European journal of pharmacology, 2010 Feb 22, 5(2)
Anti-IL-6 receptor antibody suppressed T cell activation by inhibiting IL-2 production and inducing regulatory T cells.
[Abstract]T cell activation is crucial to the pathogenesis and progression of rheumatoid arthritis. Tumour necrosis factor-alpha (TNFalpha) and interleukin (IL)-6 inhibitors show marked efficacy in rheumatoid arthritis patients, but their impacts on T cell activation have remained unclear. To shed light on these impacts, we examined the effects of an anti-IL-6 receptor antibody and an anti-TNFalpha antibody on T cell activation in two experimental systems: spleen cells stimulated by anti-CD3 antibody, and purified splenic CD4 T cells stimulated by both anti-CD3 and anti-CD28 antibodies. Anti-IL-6 receptor antibody significantly (but only partially) suppressed T cell activation (as indicated by [(3)H]-thymidine uptake and CD25 expression) and IL-2 production in both systems, and increased the frequency of regulatory T cells among spleen cells. Anti-TNFalpha antibody had no effects in either system. Neither antibody increased the expression of markers of apoptosis in CD4 T cells. In conclusion, our results show that anti-IL-6 receptor antibody significantly (but only partially) suppressed the T cell receptor signalling-induced activation of CD4 T cells and also suggest that it achieved this partial suppression by the partial inhibition of IL-2 production and the induction of regulatory T cells. In stark contrast, anti-TNFalpha antibody had no impact on T cell activation. Extrapolating these results to the clinical treatment of rheumatoid arthritis, they suggest that IL-6 blockade inhibits T cell activation, whereas TNFalpha blockade does not.
54: Journal of immunotherapy (Hagerstown, Md. : 1997), 2010 Feb 6, 28(5)
IL-2-driven Regulation of NK Cell Receptors With Regard to the Distribution of CD16+ and CD16- Subpopulations and In Vivo Influence After Haploidentical NK Cell Infusion.
[Abstract]To characterize natural killer (NK) cell subpopulations during activation, we analyzed the NK cell receptor repertoire and functionality of purified clinical scale CD56CD3 donor NK cells during stimulation with 1000 U/mL interleukin (IL)-2 for up to 14 days. In a phase I/II trial, we investigated the efficacy and feasibility of nonidentical NK cell infusion in patients with neuroblastoma after haploidentical stem cell transplantation. After IL-2 stimulation, large differences in the distribution of CD16 and CD16 subpopulations were found in 12 donors. Thereby, surface expression for all natural cytotoxicity receptors (NCRs) and NKG2D increased. In addition, killer cell immunoglobulin-like receptor (KIR) NK cells were overgrown by KIR proportion and the homing receptor CD62L was lost during stimulation. NK cell cytotoxicity against K562 and neuroblastoma cells increased and significantly higher cytokine secretion (eg, interferon-gamma, tumor necrosis factor-beta, macrophage inflammatory protein-1alpha, macrophage inflammatory protein-1beta) was observed after IL-2 stimulation compared with freshly isolated NK cells. However, NK cells of donors showing an initially enhanced cytotoxicity combined with NCR and CD69 expression, seemed to be exhausted and did not favor a stimulation period over 9 days. When IL-2-stimulated NK cells were given to transplant recipients, they induced a decrease of peripheral blood NK, in particular of CD56-NK cells. Our data indicate that IL-2 stimulation increases the expression of activating receptors and emphasizes mechanisms beside KIR/human leukocyte antigen. Furthermore, the results suggest that the expansion period of purified NK cells has to be individualized to optimize NK cell immunotherapy.
55: Japanese journal of clinical oncology, 2010 Jan 27, 184(3)
Combination Therapy of Interleukin-2 and Sorafenib Improves Survival Benefits and Prevents Spontaneous Pulmonary Metastasis in Murine Renal Cell Carcinoma Models.
[Abstract]OBJECTIVE: The objective of this study was to evaluate the benefits of combination therapy consisting of recombinant human interleukin-2 and sorafenib for survival efficacy and the suppression of metastasis in murine renal cell carcinoma models. METHODS: Lung-metastasized renal cell carcinoma mice were treated with various combinations of recombinant human interleukin-2 and sorafenib. Tumor growth was observed using a bioluminescence imaging system. Next, the nephrectomized renal cell carcinoma mice were administered various combinations of recombinant human interleukin-2 and sorafenib, followed by a lung resection in order to examine lung metastasis by bioluminescence imaging. RESULTS: The increased life-span ratio in mice receiving combination therapy was 1.45, whereas that in mice treated with sorafenib or recombinant human interleukin-2 alone therapy was 1.28 and 1.07, respectively. The concomitant administration of recombinant human interleukin-2 and sorafenib had a metastasis-inhibitory effect, whereas the other treatments failed. CONCLUSIONS: These findings indicate that combination therapy of recombinant human interleukin-2 and sorafenib may offer better outcomes than either monotherapy with recombinant human interleukin-2 or sorafenib with respect to survival benefits and the prevention of pulmonary metastasis in renal cell carcinoma patients.
56: Journal of immunology (Baltimore, Md. : 1950), 2010 Jan 25, 184(3)
Transient CD86 Expression on Hepatitis C Virus-Specific CD8+ T Cells in Acute Infection Is Linked to Sufficient IL-2 Signaling.
[Abstract]Costimulatory signals via B7/CD28 family molecules (signal 2) are critical for effective adaptive CD8(+) T cell immune responses. In addition to costimulatory signals, B7/CD28 family coinhibitory receptor/ligands that modulate immune responses have been identified. In acute hepatitis C virus (HCV) infection, programmed death receptor 1, an inhibitory receptor in the CD28 family, is highly expressed on virus-specific CD8(+) T cells, yet vigorous immune responses often develop. We hypothesized that other costimulatory signals present during the acute phase of HCV infection would be important to counter this negative signaling. In this study, we found that CD86 was highly expressed on HCV-specific CD8(+) T cells early in acute HCV infection and was lost on transition to chronic HCV infection; the expression of CD86 was different from other activation markers, because expression was delayed after in vitro TCR stimulation and required sufficient IL-2 signaling; and HCV-specific CD8(+) T cells in the liver of patients with chronic HCV infection were highly activated (CD69, CD38, and HLA-DR expression), but only a minority expressed CD86 or showed evidence of recent IL-2 signaling (low basal phosphorylated STAT5), despite persistent viremia. Our study identified B7 ligand expression on HCV-specific CD8(+) T cells as a distinct marker of effective T cell stimulation with IL-2 signaling in acute HCV infection. Expression of costimulatory molecules, such as CD86, early in HCV infection may be essential in overcoming inhibitory signals from the high level of programmed death receptor 1 expression also seen at this phase of infection.
57: mAbs, 2010 Jan 8, 2(1)
Differential effects of IL-2 and IL-21 on expansion of the CD4(+)CD25(+)Foxp3(+) T regulatory cells with redundant roles in natural killer cell mediated antibody dependent cellular cytotoxicity in chronic lymphocytic leukemia.
[Abstract]CD4(+) CD25(+) regulatory T cells are expanded in solid and hematological malignancies including chronic lymphocytic leukemia (CLL). Several cytokines and co-stimulatory molecules are required for generation, survival and maintenance of their suppressive effect. We and others have shown direct cytotoxic effect of the novel common gamma chain cytokine interleukin (IL)-21 on primary B cells from CLL patients. Since members of this family of cytokines are known to exhibit their effects on diverse immune cells, we have examined the effects of IL-21 on CLL patient derived regulatory T cell (Treg) induction, expansion and the inhibitory effect on natural killer cells in vitro. We demonstrate here the expression of IL-21 receptor in CD4(+)CD25(High) regulatory cells from CLL patients. In contrast to IL-2, the IL-21 cytokine failed to mediate expansion of regulatory T cells or induced expression of Foxp3 in CD4(+)CD25(Intermediate) or CD4(+)CD25(Dim/-) T cells in whole blood derived from CLL patients. Interestingly, in contrast to their differential effects on expansion of the CD4(+)CD25(+)Foxp3(+)T cells, IL-2 and IL-21 exhibited a redundant role in Treg mediated suppression of NK cell mediated antibody dependent cytotoxicity function. Given the infusion related toxicities and pro-survival effect of IL-2 in CLL, these studies provide a rationale to explore IL-21 as an alternate gamma chain cytokine in CLL therapy.
58: Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K, 2010 Jan 14, 136(2)
Selective elimination of a chemoresistant side population of B-CLL cells by cytotoxic T lymphocytes in subjects receiving an autologous hCD40L/IL-2 tumor vaccine.
[Abstract]Side-population (SP) analysis identifies precursor cells in normal and malignant tissues. Cells with this phenotype have increased resistance to many cytotoxic agents, and may represent a primary drug-resistant population in malignant diseases. To discover whether drug-resistant malignant SP cells are nonetheless sensitive to immune-mediated killing, we first established the presence of a malignant CD5(+)CD19(+) SP subset in the blood of 18/21 subjects with B-cell chronic lymphocytic leukemia (B-CLL). We examined the fate of these cells in six of these individuals who received autologous human CD40 ligand and interleukin-2 (hCD40L/IL-2) gene-modified tumor cells as part of a tumor vaccine study. Vaccinated patients showed an increase in B-CLL-reactive T cells followed by a corresponding decline in circulating CD5(+)CD19(+) SP cells. T-cell lines and clones generated from vaccinated patients specifically recognized B-CLL SP tumor cells. Elimination of SP cells is likely triggered by their increased expression of target antigens, such as receptor for hyaluronan-mediated motility (RHAMM), after stimulation of the malignant cells by hCD40L, as CD8(+) RHAMM-specific T cells could be detected in the peripheral blood of immunized patients and were associated with the decline in B-CLL SP cells. Hence, malignant B cells with a primary drug-resistant phenotype can be targeted by T- cell-mediated effector activity after immunization of human subjects.Leukemia advance online publication, 14 January 2010; doi:10.1038/leu.2009.281.
59: Genes and immunity, 2010 Jan 14, 136(2)
Association of the AFF3 gene and IL2/IL21 gene region with juvenile idiopathic arthritis.
[Abstract]Recent genetic studies have led to identification of numerous loci that are associated with susceptibility to autoimmune diseases. The strategy of using information from these studies has facilitated the identification of novel juvenile idiopathic arthritis (JIA) susceptibility loci, specifically, PTPN22 and IL2RA. Several novel autoimmune susceptibility loci have recently been identified, and we hypothesise that single-nucleotide polymorphisms (SNPs) within these genes may also be JIA susceptibility loci. Five SNPs within the genes AFF3, IL2/IL21, IL7R, CTLA4 and CD226, previously associated with multiple autoimmune diseases were genotyped, in a large data set of Caucasian JIA patients and controls, and tested for association with JIA. We identified two susceptibility loci for JIA, AFF3 and the IL2/IL21 region and additional weak evidence supporting an association with the CTLA4 and IL7R genes, which warrant further investigation. All results require validation in independent JIA data sets. Further characterisation of the specific causal variants will be required before functional studies can be performed.Genes and Immunity advance online publication, 14 January 2010; doi:10.1038/gene.2009.105.
60: Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 2010 Jan 4, 136(2)
Randomized Study of Intensified Anthracycline Doses for Induction and Recombinant Interleukin-2 for Maintenance in Patients With Acute Myeloid Leukemia Age 50 to 70 Years: Results of the ALFA-9801 Study.
[Abstract]PURPOSE: In patients with acute myeloid leukemia (AML), induction chemotherapy is based on standard doses of anthracyclines and cytarabine. High doses of cytarabine have been reported as being too toxic for patients older than age 50 years, but few studies have evaluated intensified doses of anthracyclines. PATIENTS AND METHODS: In this randomized Acute Leukemia French Association 9801 (ALFA-9801) study, high doses of daunorubicin (DNR; 80 mg/m(2)/d x 3 days) or idarubicin (IDA4; 12 mg/m(2)/d x 4 days) were compared with standard doses of idarubicin (IDA3; 12 mg/m(2)/d x 3 days) for remission induction in patients age 50 to 70 years, with an event-free survival (EFS) end point. After two consolidation courses based on intermediate doses of cytarabine, patients in continuous remission were randomly assigned to receive or not receive maintenance therapy with recombinant interleukin-2 (rIL-2; 5 x 10(6) U/m(2) x 5 days each month) for a total duration of 12 months. A total of 468 patients entered the study (median age, 60 years). RESULTS: Overall complete remission rate was 77% with significant differences among the three randomization arms (83%, 78%, and 70% in the IDA3, IDA4, and DNR arms, respectively; P = .04). However, no significant differences were observed in relapse incidence, EFS, or overall survival among the three arms. In the 161 patients randomly assigned for maintenance therapy, no difference in outcome was observed between the rIL-2 and the no further treatment arms. CONCLUSION: Neither intensification of anthracycline doses nor maintenance with rIL-2 showed a significant impact on AML course, at least as scheduled in this trial.
61: Journal of immunology (Baltimore, Md. : 1950), 2009 Dec 23, 136(2)
Structural Basis for the Blockage of IL-2 Signaling by Therapeutic Antibody Basiliximab.
[Abstract]IL-2 signaling plays a central role in the initiation and activation of immune responses. Correspondingly, blockage of this pathway leads to inhibition of the immune system and would provide some therapeutic benefits. Basiliximab (Simulect), a therapeutic mAb drug with specificity against IL-2Ralpha of T cells, was approved by U.S. Food and Drug Administration in 1998. It has been proven to be effective in the suppression of the IL-2 pathway and hence has been widely used to prevent allograft rejection in organ transplantation, especially in kidney transplants. In this study, we report the crystal structure of the basiliximab Fab in complex with the ectodomain of IL-2Ralpha at 2.9 A resolution. In the complex structure, the Fab interacts with IL-2Ralpha with extensive hydrophobic and hydrophilic interactions, accounting for a high binding affinity of 0.14 nM. The Ag binding site of basiliximab consists of all six CDR loops that form a large binding interface with a central shallow hydrophobic groove surrounded by four hydrophilic patches. The discontinuous epitope is composed of several segments from the D1 domain and a minor segment from the D2 domain that overlap with most of the regions responsible for the interactions with IL-2. Thus, basiliximab binding can completely block the interactions of IL-2 with IL-2Ralpha and hence inhibit the activation of the IL-2 signal pathway. The structural results also provide important implications for the development of improved and new IL-2Ralpha-targeted mAb drugs.
62: Proceedings of the National Academy of Sciences of the United States of America, 2009 Dec 14, 53(7)
Homeostatic imbalance of regulatory and effector T cells due to IL-2 deprivation amplifies murine lupus.
[Abstract]The origins and consequences of a regulatory T cell (Treg) disorder in systemic lupus erythematosus (SLE) are poorly understood. In the (NZBxNZW) F(1) mouse model of lupus, we found that CD4(+)Foxp3(+) Treg failed to maintain a competitive pool size in the peripheral lymphoid organs resulting in a progressive homeostatic imbalance of CD4(+)Foxp3(+) Treg and CD4(+)Foxp3(-) conventional T cells (Tcon). In addition, Treg acquired phenotypic changes that are reminiscent of IL-2 deficiency concomitantly to a progressive decline in IL-2-producing Tcon and an increase in activated, IFN-gamma-producing effector Tcon. Nonetheless, Treg from lupus-prone mice were functionally intact and capable to influence the course of disease. Systemic reduction of IL-2 levels early in disease promoted Tcon hyperactivity, induced the imbalance of Treg and effector Tcon, and strongly accelerated disease progression. In contrast, administration of IL-2 partially restored the balance of Treg and effector Tcon by promoting the homeostatic proliferation of endogenous Treg and impeded the progression of established disease. Thus, an acquired and self-amplifying disruption of the Treg-IL-2 axis contributed essentially to Tcon hyperactivity and the development of murine lupus. The reversibility of this homeostatic Treg disorder provides promising approaches for the treatment of SLE.
63: HIV medicine, 2009 Dec 8, 53(7)
Persistence of CCR5 usage among primary human immunodeficiency virus isolates of individuals receiving intermittent interleukin-2.
[Abstract]Objective To investigate the impact of intermittent interleukin-2 (IL-2) plus combination antiretroviral therapy (cART) on HIV-1 entry co-receptor use. Methods Primary HIV-1 isolates were obtained from 54 HIV-1-positive individuals at baseline and after 12 months using co-cultivation of peripheral blood mononuclear cells (PBMC) with activated PBMC of HIV-negative healthy donors. HIV-1 co-receptor use was determined on U87-CD4 cells. Results Fourteen out of the 21 (67%) IL-2-treated individuals harbouring a primary CCR5-dependent (R5) HIV-1 isolate at baseline confirmed an R5 virus isolation after 12 months in contrast to 3 out of 7 (43%) of those receiving cART only. After 12 months, only 1 R5X4 HIV-1 isolate was obtained from 21 cART+IL-2-treated individuals infected with an R5 virus at entry (5%) vs. 2/7 (29%) patients receiving cART alone, as confirmed by a 5-year follow-up on some individuals. Conclusions Intermittent IL-2 administration plus cART may prevent evolution towards CXCR4 usage in individuals infected with R5 HIV-1.
64: International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, 2009 Dec 10, 53(7)
The efficacy of catheters coated with minocycline and rifampin in the prevention of catheter-related bacteremia in cancer patients receiving high-dose interleukin-2.
[Abstract]High-dose interleukin-2 (HDIL-2) has proven to be an effective treatment for metastatic renal cell carcinoma and melanoma. Previous studies have shown an increase in catheter-related bacteremia (CRB) in patients on HDIL-2. The primary objective of this study was to evaluate the effectiveness of minocycline and rifampin-coated catheters (M/R-C) in reducing CRB in cancer patients on HDIL-2. This was a retrospective study where non-coated catheters (NC-C) and M/R-C were used for the administration of HDIL-2 before and after December 2004, respectively. Data collected included demographics, cancer type, catheter type, antibiotic prophylaxis, and infection rates. A total of 107 episodes of catheter use for HDIL-2 were evaluated in 78 patients (30 episodes in patients with M/R-C vs. 77 with NC-C). A total of nine episodes of CRB were identified, all in patients with NC-C (M/R-C 0% vs. NC-C 12%; p=0.06). The median time to bacteremia was 11 days (range 1-315 days). A log-rank test showed a trend that the M/R-C group had lower probability of getting CRB than the NC-C group (p=0.06). The use of M/R-C in patients on HDIL-2 therapy for advanced melanoma and renal cell carcinoma may have reduced the risk of CRB to nil. CRB still occurred despite antibiotic prophylaxis in patients with NC-C.
65: Autoimmunity, 2009 Dec 14, 53(7)
Defective in vitro IL-2 production in lupus is an early but secondary event paralleling disease activity: Evidence from the murine parent-into-F1 model supports staging of IL-2 defects in human lupus.
[Abstract]T cell defects are a well described feature of both human and murine lupus however their exact significance is unclear. Evidence from an induced model of lupus, the P --> F1 model of chronic lupus-like GVHD demonstrates that a secondary inducible T cell defect in in vitro IL-2 and CTL responses occurs early in the course of lupus-like disease and well in advance of clinical disease. Defective Th cell function was probed using a novel approach categorizing the response to two stimuli:1) the MHC self restricted response, termed self +X; and 2) the allogeneic response. Using this approach, lupus mice exhibited similar in vitro Th cell pattern i.e. an absent S+X response but preserved allogeneic (termed - /+). In contrast, human lupus patients exhibited three possible response patterns, +/+, - /+ or - / - with more severe in vitro T cell impairment correlated with more severe disease. Similarly, patients with other T cell mediated conditions i.e. HIV infection or renal allograft recipients, also exhibited more severe in vitro T cell impairment with greater disease activity or greater immunosuppression respectively. The similar Th response patterns in human and murine T cell mediated conditions indicates that the underlying mechanisms involved are not disease specific but instead reflect common immune responses and validate the use of the P --> F1 model for future studies of T cell mediated conditions. These results support the use of prospective monitoring of IL-2 responses in lupus patients. Successful adaptation of this approach to the clinical setting could allow not only earlier therapeutic intervention and reduced organ damage but also earlier tapering of pharmacological agents and reduced untoward effects.
66: Urology, 2009 Dec 4, 53(7)
Clinical Significance of IL-2, IL-10, and TNF-alpha in Prostatic Secretion of Patients With Chronic Prostatitis.
[Abstract]OBJECTIVES: To explore the clinical significance of interleukin-2 (IL-2), interleukin-10 (IL-10), and tumor necrosis factor alpha (TNF-alpha) in expressed prostatic secretions (EPS) of patients with different types of chronic prostatitis (CP). METHODS: Fifty-seven CP patients and 12 healthy males (controls) were investigated. The CP patients were evaluated through routine examination of urine, EPS, 2 glasses urine culture, and the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) score and classified by the NIH prostatitis diagnostic criteria. The levels of cytokines TNF-alpha, IL-10, and IL-2 in the EPS were measured by two-antibody enzyme-linked immunosorbent assay. RESULTS: CP patients fell into 3 groups: type II (n = 10), type IIIa (n = 26), and type IIIb (n = 21). EPS TNF-alpha and IL-10 levels were significantly higher in type II and type IIIa than in type IIIb and control groups. The levels of IL-2 were lower than control in all CP groups, but only type II was statistically different from the controls. In the CP patients, the level of TNF-alpha was positively related to the white blood cell counts (r = .77; P <.01), and the level of IL-10 was positively related to the NIH-CPSI scores (r = .55; P <.01). CONCLUSIONS: Determination of variety expression of TNF-alpha, IL-10, and IL-2 in the EPS of CP patients may provide a potential indicator for clinical diagnosis classification and an indicator to evaluate the effect of treatment of CP.
67: The Journal of clinical investigation, 2009 Dec 1, 58(12)
CD27 sustains survival of CTLs in virus-infected nonlymphoid tissue in mice by inducing autocrine IL-2 production.
[Abstract]Immunity to infections relies on clonal expansion of CD8+ T cells, their maintenance as effector CTLs, and their selection into a memory population. These processes rely on delivery of survival signals to activated CD8+ T cells. We here reveal the mechanism by which costimulatory CD27-CD70 interactions sustain survival of CD8+ effector T cells in infected tissue. By unbiased genome-wide gene expression analysis, we identified the Il2 gene as the most prominent CD27 target gene in murine CD8+ T cells. In vitro, CD27 directed IL-2 expression and promoted clonal expansion of primed CD8+ T cells exclusively by IL-2-dependent survival signaling. In mice intranasally infected with influenza virus, Cd27-/- CD8+ effector T cells displayed reduced IL-2 production, accompanied by impaired accumulation in lymphoid organs and in the lungs, which constitute the tissue effector site. Reconstitution of Cd27-/- CD8+ T cells with the IL2 gene restored their accumulation to wild-type levels in the lungs, but it did not rescue their accumulation in lymphoid organs. Competition experiments showed that the IL-2 produced under the control of CD27 supported effector CD8+ T cell survival in the lungs in an autocrine manner. We conclude that CD27 signaling directs the IL-2 production that is reportedly essential to sustain survival of virus-specific CTLs in nonlymphoid tissue.
68: European journal of immunology, 2009 Nov 30, 183(11)
IL-7 is superior to IL-2 for ex vivo expansion of tumour-specific CD4(+) T cells.
[Abstract]It is well-established that tumours hinder both natural and vaccine-induced tumour-specific CD4(+) memory-like T cell responses. Adoptive T-cell therapy has the potential to circumvent functional tolerance and enhance anti-tumour protective responses. While protocols suitable for the expansion of cytotoxic CD8(+) T cells are currently available, data on tumour-specific CD4(+) T cells remain scarce. We report here that CD4(+) T cells sensitized to tumour-associated antigens in vivo, proliferate in vitro in response to IL-7 without the need for exogenous antigen stimulation and accumulate several fold while preserving a memory-like phenotype. Both cell proliferation and survival accounts for the outgrowth of tumour-sensitized T cells among other memory and naive lymphocytes following exposure to IL-7. Also IL-2, previously used to expand anti-tumour CTL, promotes tumour-specific CD4(+) T cell accumulation; however IL-7 is superior to IL-2 at preserving lymphocyte viability, in vitro and in vivo, maintaining those properties, which are required by helper CD4(+) T cells to confer therapeutic efficacy upon transplantation in tumour-bearing hosts. Together our data support a unique role for IL-7 in retrieving memory-like CD4(+) T cells suitable for adoptive T cell therapy.
69: Diabetologia, 2009 Nov 28, 183(11)
Targeting of IL-2 receptor with a caspase fusion protein disrupts autoimmunity in prediabetic and diabetic NOD mice.
[Abstract]AIMS/HYPOTHESIS: Interruption of IL-2 signalling is an attractive therapeutic target in autoimmune disorders. In this study we evaluated the effect of a fusion protein composed of IL-2 and caspase-3 (IL2-cas) on NOD mice, as compared with disease induction by cyclophosphamide. METHODS: IL2-cas was assessed in NOD mice at various ages and in conjunction with cyclophosphamide administration. The effect of IL2-cas on diabetogenic cells was evaluated in adoptive transfer experiments and in cell suspension in vitro. RESULTS: IL2-cas induced apoptosis in T cells expressing the alpha chain of the IL-2 receptor (cluster of differentiation [CD]25) in vitro, with superior survival of T cells expressing CD4 and forkhead box P3 (FOXP3). The fusion protein decreased mixed lymphocyte reactivity, and pretreatment with IL2-cas decreased the efficacy of adoptive transfer of diabetes into NOD severe combined immunodeficiency mice. Administration of one dose of IL2-cas decreased the incidence of diabetes in NOD mice, showing a superior beneficial effect when administered at young age, and effectively blocked induction of hyperglycaemia by cyclophosphamide, reducing the severity of islet inflammation. Administration of IL2-cas caused an acute increase in CD25(-)FOXP3(+) T cells in the lymph nodes, pancreas and thymus in NOD mice, with similar effects in wild-type mice. Administration of IL2-cas after onset of hyperglycaemia resulted in superior survival. CONCLUSIONS/INTERPRETATION: Targeted elimination of cells expressing the IL-2 receptor by this fusion protein disrupts the autoimmune pathogenesis in prediabetic and diabetic NOD mice, despite depletion of CD25(+) regulatory T cells. Furthermore, this particular fusion protein is permissive to the development of FOXP3(+) T cells that might contribute to protracted protection from the progression of insulitis and overt hyperglycaemia.
70: Experimental parasitology, 2009 Nov 25, 88(10)
Cross immunity of DNA vaccine pVAX1-cSZ2-IL-2 to Eimeria tenella, E. necatrix and E. maxima.
[Abstract]The study describes cross protection experiments with chimeric DNA vaccine pVAX1-cSZ2-IL-2 to determine its efficacy against four important Eimeria species. Seven-day-old chickens were randomly divided into 9 groups; group 1 negative control, groups 2, 3, 4, 5 positive controls; and groups 6, 7, 8 and 9 experimental groups. On day 7 and 14, groups 1 - 5 were injected with TE buffer, and groups 6 - 9 with the vaccine. At 21 days of age, all chickens were inoculated with 5 x 10(4) sporulated oocysts except for the negative control. Groups 2 and 6 were inoculated with E. tenella, groups 3 and 7 with E.necatrix, groups 4 and 8 with E. acervulina and groups 5 and 9 with E. maxima. Seven days later, all chickens were weighed and slaughtered to obtain intestinal samples. Efficacy of immunization was evaluated on the basis of oocyst decrease ratio, lesion score, body-weight gain and anti-coccidial index. The results indicated that the recombinant plasmid can induce host immune responses by alleviating intestinal lesions, body weight loss and oocyst ratio and imparting good protection against E. tenella and E.acervulina, medium protection against E. necatrix but little effect against E. maxima. It is concluded that the conserved antigen can provide cross protection and should be explored further.
71: Fish & shellfish immunology, 2009 Nov 24, 88(10)
Endosulfan increases seric interleukin-2 like (IL-2L) factor and immunoglobulin M (IgM) of Nile tilapia (Oreochromis niloticus) challenged with Aeromona hydrophila.
[Abstract]Endosulfan is a persistent organochlorine insecticide which is extremely toxic to fish. It is known to induce immunological alterations in juvenile Nile tilapia (Oreochromis niloticus) such as increases in phagocytic activity and reactive oxygen species production of spleen macrophages. The purpose of the present study was to demonstrate the effects of acute exposure to a sublethal concentration of endosulfan (7 ppb, 96 h) on parameters of the adaptive humoral immune response of the aforementioned aquatic organism. The effect of endosulfan on the capacity of immune cells to produce interleukin-2 like (IL-2L) factor and immunoglobulin M (IgM) in response to a challenge with (1/2) LD50 of the infectious bacteria Aeromonas hydrophila was evaluated. Experimental results indicate that short, sublethal, endosulfan exposure triggers a succession of events beginning with non-specific activation of macrophages followed by an exacerbated synthesis of the IL-2L factor by activated B cells. This leads to significantly increased secretion of IgM and could in turn facilitate autoantibody production and the development of autoimmune pathologies.
72: Journal of cancer research and clinical oncology, 2009 Nov 19, 29(11)
Promoter hypermethylation in tumour suppressor genes and response to interleukin-2 treatment in bladder cancer: a pilot study.
[Abstract]PURPOSE: Non-muscle invasive bladder cancer (BC) is a highly recurrent disease, with the first recurrences arising shortly after transurethral resection of the bladder (TURB). Topical administration of interleukin-2 (IL-2) has been shown as an effective adjuvant therapy for BC; however, predictive biomarkers that may identify suitable subgroups of patients are lacking. In this pilot study we sought to determine the prognostic value of epigenetic and genetic inactivation of tumour suppressor genes (TSGs) among BC patients treated with IL-2. METHODS: After complete TURB, patients with multifocal superficial BC were treated with five daily intravesical instillations of IL-2. Promoter hypermethylation in six TSGs and the TP53 gene mutations were prospectively assessed by methylation-specific PCR and automated capillary single-strand conformation polymorphism in 21 primary bladder cancer specimens and ten bladder wall biopsies collected during follow-up. RESULTS: After IL-2 treatment, 9 out of 21 (43%) patients did not develop recurrent tumour within the 1 year of follow-up period. The mean duration of recurrence-free survival in the rest of the study group was 112 days. In the current pilot study, BC with p16 gene hypermethylation had a lower risk of recurrence after treatment with IL-2, as compared to IL-2 treated BC without p16 hypermethylation (p = 0.02). Significant associations were observed between tumour grade and the mean methylation index (p = 0.003), as well as the hypermethylation of the RARbeta gene (p = 0.048). CONCLUSION: Our preliminary data suggest that DNA methylation biomarkers may assist in selection of BC patients for efficient IL-2 therapy.
73: Gut, 2009 Dec, 58(12)
Interleukin 2 targeted therapy in inflammatory bowel disease.
[Abstract]The aim of this study is to compare the histological grading of acute organ rejection according to the Banff score with intracellular interleukin-2 (IL-2) concentrations in cytotoxic CD8+ T cells from peripheral blood samples. 66 recipients after liver transplantation and 20 healthy controls were included into this study. Blood samples of liver transplant recipients were collected beside routine visits or, in case of suspected organ rejection, with additional liver biopsy. For cytometry, the blood cells were stained with CD3, CD8 and intracellular-IL-2. The percentage of cells with detectable intracellular IL-2 was significantly increased in patients with acute rejection (n = 7, P < 0.001, t Test) compared to recipients without rejection. The percentage of cells with detectable intracellular IL-2 (mean +/- SEM) was 7.6 +/- 0.9% in rejection patients, 2.3 +/- 0.22% in stable liver transplant recipients, and 14 +/- 2.99% in healthy controls. Intracellular IL-2 correlates to the Banff score in rejection patients (Spearmans-rho = 0.81, P < 0.05). This cytometric method shows a good sensitivity (71%) with a cut-off based on a high specificity of 95% for histological proven organ rejection in our study cohort. Measurement of intracellular IL-2 in cytotoxic CD8+ T-lymphocytes by flow cytometry correlates very well to the histological grading according to the Banff score and shows a good sensitivity and excellent specificity in acute organ rejection.
74: The Journal of biological chemistry, 2009 Nov 18, 29(11)
Protein phosphatase 2A (PP2A) regulates interleukin-2 receptor complex formation and JAK3/STAT5 activation.
[Abstract]Reversible protein phosphorylation plays a key role in interleukin-2 (IL-2) receptor mediated activation of Janus tyrosine kinase 3 (JAK3) and Signal Transducer and Activator of Transcription 5 (STAT5) in lymphocytes. Although the mechanisms governing IL-2 induced tyrosine phosphorylation and activation of JAK3/STAT5 have been extensively studied, the role of serine/threonine phosphorylation in controlling these effectors remains to be elucidated. Using phospho-amino acid analysis, JAK3 and STAT5 were determined to be serine and tyrosine phosphorylated in response to IL-2 stimulation of the human NK-like cell line, YT. IL-2 stimulation also induced serine/threonine phosphorylation of IL-2Rbeta, but not IL-2Rgamma. To investigate the regulation of serine/threonine phosphorylation in IL-2 signaling, the roles of Protein Phosphatase 1 (PP1) and 2A (PP2A) were examined. Inhibition of phosphatase activity by calyculin A treatment of YT cells resulted in a significant induction of serine phosphorylation of JAK3 and STAT5, and serine/threonine phosphorylation of IL-2Rbeta. Moreover, inhibition of PP2A, but not PP1, diminished IL-2 induced tyrosine phosphorylation of IL-2Rbeta, JAK3 and STAT5, and abolished STAT5 DNA binding activity. Serine/threonine phosphorylation of IL-2Rbeta by a staurosporine sensitive kinase also blocked its association with JAK3 and IL-2Rgamma in YT cells. Taken together, these data indicate that serine/threonine phosphorylation negatively regulates IL-2 signaling at multiple levels, including receptor complex formation and JAK3/STAT5 activation, and that this regulation is counteracted by PP2A. These findings also suggest that PP2A may serve as a therapeutic target for modulating JAK3/STAT5 activation in human disease.
75: Nan fang yi ke da xue xue bao = Journal of Southern Medical University, 2009 Nov 20, 29(11)
[Effect of cytotoxin interleukin-2-pseudomonas exotoxin 66 on corneal allograft rejection in mice.]
[Abstract]OBJECTIVE: To study the immunosuppressive effect of the interleukin-2-pseudomonas exotoxin 66(IL-2-PE66) on murine corneal allograft rejection. METHODS: Thirty-six recipient female BALB/c mice received corneal allografts from C57BL/6 mice and were divided randomly into treatment and control groups. The condition of the grafts was observed twice a week. On days 10, 15, 25 and 35 after the transplantation, the operated eyes were removed for pathological examinations. Peripheral blood samples were also collected for analysis of T cell subsets and T lymphocyte colony forming unit (T-CFU) assay. RESULTS: The survival time of corneal allograft averaged 15.8-/+2.1 days in the control group and 31.2-/+2.9 days in the treatment group. The CD(4)(+)/ CD(8)(+)/ of the T cell subsets 15 days after the operation was 1.26-/+0.23 in the treatment group and 2.01-/+0.23 in the control group, with T-CFU of 201-/+18.2 and 286-/+16.8, respectively. CONCLUSION: IL-2-PE66 can delay the development of corneal graft rejection, significantly reduce the percentage of T helper cells, and weaken the aggregation of the peripheral T cells.
76: Cancer research, 2009 Nov 17, 29(11)
The Human Ortholog of Granulocyte Macrophage Colony-Stimulating Factor and Interleukin-2 Fusion Protein Induces Potent Ex vivo Natural Killer Cell Activation and Maturation.
[Abstract]Natural killer (NK) cells are appealing cellular pharmaceuticals for cancer therapy because of their innate ability to recognize and kill tumor cells. Therefore, the development of methods that can enhance the potency in their anticancer effect would be desirable. We have previously shown that a murine granulocyte macrophage colony-stimulating factor (GM-CSF)/interleukin 2 (IL-2) fusion protein displays novel antitumor properties in vivo compared with both cytokines in combination due to recruitment of NK cells. In the present work, we have found that human ortholog of the GM-CSF/IL-2 fusion protein (a.k.a. hGIFT2) induces robust NK cell activation ex vivo with significant secretion of RANTES and a 37-fold increase in IFNgamma production when compared with either IL-2 or GM-CSF single cytokine treatment or their combination. Moreover, hGIFT2 upregulates the expression of NK cell activating receptors NKp44, NKp46, and DNAM-1 (CD226), as well as CD69, CD107a, and IL-2Rbeta expression. In addition, hGIFT2 promotes NK cell maturation, based on the downregulation of CD117 expression and upregulation of CD11b. This phenotype correlates with significantly greater cytotoxicity against tumor cells. At the molecular level, hGIFT2 leads to a potent activation of Janus-activated kinases (JAK) downstream of both IL-2 and GM-CSF receptors (JAK1 and JAK2, respectively) and consequently leads to a hyperphosphorylation of signal transducers and activators of transcription (STAT)1, STAT3, and STAT5. In conclusion, hGIFT2 fusokine possesses unique biochemical properties distinct from IL-2 and GM-CSF, constitutes a novel and potent tool for ex vivo NK cell activation and maturation, and may be of use for cancer cell immunotherapy. [Cancer Res 2009;69(23):9020-8].
77: International journal of cancer. Journal international du cancer, 2009 Oct 29, 70(5)
Therapy-induced antitumor vaccination in neuroblastomas by the combined targeting of IL-2 and TNFalpha.
[Abstract]L19-IL2 and L19TNFalpha are fusion proteins composed of L19(scFv), specific for the angiogenesis-associated ED-B containing fibronectin isoform, and IL-2 or TNFalpha. Thanks to the tumor targeting properties of L19, IL-2 and TNFalpha concentrate at therapeutic doses at the tumor vascular level. To evaluate the therapeutic effects of L19-IL2 and L19mTNFalpha in neuroblastoma (NB)-bearing mice, A/J mice bearing Neuro2A or NIE115 NB were systemically treated with L19-IL2 and L19mTNFalpha, alone or in combination protocols. 70% of Neuro2A- and 30% of NIE115-bearing mice were cured by the combined treatment with L19-IL2 and L19mTNFalpha, and further rejected a homologous tumor challenge, indicating specific antitumor immune memory. The immunological bases of tumor cure and rejection were studied. A highly efficient priming of CD4(+) T helper cells and CD8(+) CTL effectors was generated, paralleled by massive infiltration in the tumor tissue of CD4(+) and CD8(+) T cells at day 16 after tumor cell implantation, when, after therapy, tumor volume was drastically reduced and tumor necrosis reached about 80%. The curative treatment resulted in a long-lasting antitumor immune memory, accompanied by a mixed Th1/Th2 type of response. Concluding, L19-IL2 and L19mTNFalpha efficiently cooperate in determining a high percentage of NB cure that, in our experimental models, is strongly associated to the generation of adaptive immunity involving CD4(+) and CD8(+) T cells. (c) 2009 UICC.
78: Anticancer research, 2009 Oct, 29(10)
Single-institution outcome of high-dose interleukin-2 (HD IL-2) therapy for metastatic melanoma and analysis of favorable response in brain metastases.
[Abstract]BACKGROUND: High-dose interleukin-2 (HD IL-2) is known to produce durable responses in metastatic melanoma. The purpose of this study was to evaluate the response of metastatic melanoma to treatment with HD IL-2. PATIENTS AND METHODS: A retrospective analysis was performed on all adult patients with stage IV melanoma treated with HD IL-2 from January 2000 to October 2008 at the University of Minnesota. HD IL-2 was given intravenously every 8 hours at 600,000 IU/kg for a maximum of 14 doses per course. RESULTS: Fifteen patients with metastatic melanoma had been treated with HD IL-2. There were 4 patients exhibiting some response, with 1 complete response (CR), 1 partial response (PR), 1 mixed response (MR) and 2 stable disease (SD). Average time to disease progression (TTDP) was 5.67 months. Two patients had complete resolution of brain lesions after HD IL-2 therapy. One of these patients experienced CR and is disease free 34 months after stopping therapy. The other patient experienced MR and is currently alive with disease, but without recurrence of brain lesions. Twelve out of the 15 patients received 2 courses of therapy. Common grade (G) 3 and 4 adverse events included: hyperbilirubinemia (G 3=26.67%), hypotension (G 3=6.67%, G 4=6.67%), peripheral edema (G 3=26.67%), and pulmonary edema (G 3=13.33%). CONCLUSION: We propose further evaluation of HD IL-2 in patients with brain metastases because this patient population is typically considered ineligible for HD IL-2 therapy.
79: Anticancer research, 2009 Oct, 29(10)
Effects of 5-FU on DNA synthesis and cytotoxicity of human lymphocytes induced by IL-2, TGF-beta3 and PGE2.
[Abstract]BACKGROUND: Low 5-fluorouracil (5-FU) concentrations cause a significant increase in DNA synthesis in mitogen-activated human lymphocytes. MATERIALS AND METHODS: We explored 2.5 microM 5-FU-induced DNA synthesis by testing 5-FU activity in hypoxanthine-aminopterin-thymidine (HAT)-containing medium, and its effect on thymidylate synthase (TS) activity and CD25 expression in interleukin (IL)-2-activated human peripheral blood mononuclear cells (PBMCs) and the combined effects with prostaglandin E(2) (PGE(2)) and transforming growth factor (TGF)-beta3. RESULTS: The co-stimulatory effect of 2.5 microM 5-FU on DNA synthesis was abrogated in HAT-cultured medium. 5-FU substantially reduced TS activity by 50% in IL-2-activated PBMCs. 5-FU combined with TGF-beta3 and PGE(2) did not alter their inhibitory effects on IL-2-activated natural killer cell cytotoxicity, but substantially affected increased DNA synthesis of cells cultured in IL-2 and co-cultured with 10 ng/ml TGF-beta3 and 10 microM PGE(2). CONCLUSION: Low 5-FU concentrations increase DNA synthesis in lymphocytes and exert a co-stimulatory activity on TGF-beta3 and PGE(2) modulation of IL-2-activated lymphocytes.
80: Journal of autoimmunity, 2009 Oct 19, 20(7)
Serum inflammatory cytokines, complement components, and soluble interleukin 2 receptor in primary biliary cirrhosis.
[Abstract]Primary biliary cirrhosis (PBC) is a chronic cholestatic autoimmune liver disease characterized by selective destruction of the intrahepatic bile ducts and highly specific serum anti-mitochondrial autoantibodies (AMA). Several studies have attempted to determine the cytokine pattern characterizing PBC, yet no definitive data have been gathered. The present study was designed to evaluate pro-inflammatory cytokines (IL-1beta, IL-6, TNFalpha), soluble IL-2 receptor (sIL-2R, e.g. soluble CD25), and complement components (C1q, C3, factor B, properdin) levels in sera from 84 patients with PBC and 41 controls. PBC was characterized by significantly higher levels of all pro-inflammatory cytokines when compared to controls; these included IL-1beta (433.3 +/- 13.2 vs. 316.6 +/- 14.7 pg/ml, P < 0.001), IL-6 (701 +/- 17.4 vs. 158 +/- 22.5 pg/ml, P < 0.001), TNFalpha (3.38 +/- 0.6 pg/ml vs. undetectable, P = 0.001), and sIL-2R (1527.1 +/- 106 vs. 566.4 +/- 28.7 U/ml, P < 0.001). Similarly, all complement components were also significantly higher in PBC compared to control sera. In conclusion, PBC sera manifest higher levels of sIL-2R and complement components and this may reflect a perpetuated immune activation. As expected, we also report that all major pro-inflammatory cytokine levels are enhanced in PBC. Further longitudinal analyses could demonstrate a correlation between these markers and disease stage or inflammatory activity, to predict histological staging, disease activity, and response to treatment.
81: Experimental dermatology, 2009 Oct 21, 20(7)
The NF-kappaB signalling pathway is involved in the LPS/IL-2-induced upregulation of FoxP3 expression in human CD4CD25 regulatory T cells.
[Abstract]Please cite this paper as: The NF-kappaB signalling pathway is involved in the LPS/IL-2-induced upregulation of FoxP3 expression in human CD4(+)CD25(high) regulatory T cells. Experimental Dermatology 2009.Abstract: Regulatory T cells (Treg) have been found to be central for host defense regulation against microbial antigens, the prevention of allergic and autoimmune diseases and the suppression of effective tumor immune responses. However, the influence of the microenvironment and the mechanisms leading to their activation in the periphery still remain unclear. In vitro infection models revealed that survival and suppressive function of Treg is improved when they are confronted with lipopolysaccharide (LPS). Because LPS initiates signalling via the receptor Toll-like receptor 4 (TLR4) and the consequent activation of the transcription factor nuclear factor-kappaB (NF-kappaB), we investigated TLR4 expression and NF-kappaB regulation in human Treg. We demonstrated that LPS in combination with IL-2 induces human CD25(+)FoxP3(+) T cells in vitro. FoxP3 expression of purified natural Treg increased and suppressive capacity was markedly improved compared with unstimulated Treg upon stimulation with LPS/IL-2. Furthermore, blockade of the NF-kappaB pathway by a selective inhibitor of IkappaB kinase (IKK)beta abrogated the upregulation of FoxP3 expression. Taken together, our results suggest an important role of the NF-kappaB signalling pathway for the induction and modulation of suppressive function of natural Treg, if they are confronted with TLR4-stimulating agents such as Gram-negative bacteria.
82: Journal of immunology (Baltimore, Md. : 1950), 2009 Nov 1, 183(9)
1,25-Dihydroxyvitamin D(3) and IL-2 combine to inhibit T cell production of inflammatory cytokines and promote development of regulatory T cells expressing CTLA-4 and FoxP3.
[Abstract]The active form of vitamin D, 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), has potent immunomodulatory properties that have promoted its potential use in the prevention and treatment of infectious disease and autoimmune conditions. A variety of immune cells, including macrophages, dendritic cells, and activated T cells express the intracellular vitamin D receptor and are responsive to 1,25(OH)(2)D(3.) Despite this, how 1,25(OH)(2)D(3) regulates adaptive immunity remains unclear and may involve both direct and indirect effects on the proliferation and function of T cells. To further clarify this issue, we have assessed the effects of 1,25(OH)(2)D(3) on human CD4(+)CD25(-) T cells. We observed that stimulation of CD4(+)CD25(-) T cells in the presence of 1,25(OH)(2)D(3) inhibited production of proinflammatory cytokines including IFN- gamma, IL-17, and IL-21 but did not substantially affect T cell division. In contrast to its inhibitory effects on inflammatory cytokines, 1,25(OH)(2)D(3) stimulated expression of high levels of CTLA-4 as well as FoxP3, the latter requiring the presence of IL-2. T cells treated with 1,25(OH)(2)D(3) could suppress proliferation of normally responsive T cells, indicating that they possessed characteristics of adaptive regulatory T cells. Our results suggest that 1,25(OH)(2)D(3) and IL-2 have direct synergistic effects on activated T cells, acting as potent anti-inflammatory agents and physiologic inducers of adaptive regulatory T cells.
83: Journal of immunology (Baltimore, Md. : 1950), 2009 Oct 19, 20(7)
Human Late Memory CD8+ T Cells Have a Distinct Cytokine Signature Characterized by CC Chemokine Production without IL-2 Production.
[Abstract]Late memory T cell skewing is observed in the setting of immune recovery after cord blood transplantation, and may be associated with inferior control of viral reactivation and cancers. Therefore, we sought to understand how late memory cells differ functionally from earlier stage memory T cells, and whether surface phenotypes associated with differentiation stages were predictably associated with functional signatures. Higher order cytokine flow cytometry allows characterization of human T cells based on complex phenotypic markers and their differential capacity to simultaneously secrete effector proteins, including cytokines and chemokines. We used 8-color, 10-parameter cytokine flow cytometry to characterize the functional activation of human late memory CD8(+) T cells defined by CD45RA and CD27 expression (CD27(-)CD45RA(+)). We assessed the 15 possible functional signatures of cells defined by production of IL-2, IFN-gamma, TNF-alpha, and MIP-1beta alone or in combination, following activation with Ags stimulating bypassing surface proteins (PMA:ionomycin) or through the TCR (e.g., viral Ags). Late memory CD8(+) T cells produced abundant amounts of CC chemokines (MIP-1beta, MIP-1alpha, and RANTES) but not IL-2. IL-2/IFN-gamma coproduction, characteristic of protective immune responses to viral infections, was absent in late memory CD8(+) T cells. These data demonstrate that functional cytokine signatures are predictably associated with CD8(+) maturation stages, and that the polarization of late memory CD8(+) T cells toward CC chemokine production and away from IL-2 production suggests a unique functional role for this subset.
84: The New England journal of medicine, 2009 Oct 15, 361(16)
Interleukin-2 therapy in patients with HIV infection.
[Abstract]BACKGROUND: Used in combination with antiretroviral therapy, subcutaneous recombinant interleukin-2 raises CD4+ cell counts more than does antiretroviral therapy alone. The clinical implication of these increases is not known. METHODS: We conducted two trials: the Subcutaneous Recombinant, Human Interleukin-2 in HIV-Infected Patients with Low CD4+ Counts under Active Antiretroviral Therapy (SILCAAT) study and the Evaluation of Subcutaneous Proleukin in a Randomized International Trial (ESPRIT). In each, patients infected with the human immunodeficiency virus (HIV) who had CD4+ cell counts of either 50 to 299 per cubic millimeter (SILCAAT) or 300 or more per cubic millimeter (ESPRIT) were randomly assigned to receive interleukin-2 plus antiretroviral therapy or antiretroviral therapy alone. The interleukin-2 regimen consisted of cycles of 5 consecutive days each, administered at 8-week intervals. The SILCAAT study involved six cycles and a dose of 4.5 million IU of interleukin-2 twice daily; ESPRIT involved three cycles and a dose of 7.5 million IU twice daily. Additional cycles were recommended to maintain the CD4+ cell count above predefined target levels. The primary end point of both studies was opportunistic disease or death from any cause. RESULTS: In the SILCAAT study, 1695 patients (849 receiving interleukin-2 plus antiretroviral therapy and 846 receiving antiretroviral therapy alone) who had a median CD4+ cell count of 202 cells per cubic millimeter were enrolled; in ESPRIT, 4111 patients (2071 receiving interleukin-2 plus antiretroviral therapy and 2040 receiving antiretroviral therapy alone) who had a median CD4+ cell count of 457 cells per cubic millimeter were enrolled. Over a median follow-up period of 7 to 8 years, the CD4+ cell count was higher in the interleukin-2 group than in the group receiving antiretroviral therapy alone--by 53 and 159 cells per cubic millimeter, on average, in the SILCAAT study and ESPRIT, respectively. Hazard ratios for opportunistic disease or death from any cause with interleukin-2 plus antiretroviral therapy (vs. antiretroviral therapy alone) were 0.91 (95% confidence interval [CI], 0.70 to 1.18; P=0.47) in the SILCAAT study and 0.94 (95% CI, 0.75 to 1.16; P=0.55) in ESPRIT. The hazard ratios for death from any cause and for grade 4 clinical events were 1.06 (P=0.73) and 1.10 (P=0.35), respectively, in the SILCAAT study and 0.90 (P=0.42) and 1.23 (P=0.003), respectively, in ESPRIT. CONCLUSIONS: Despite a substantial and sustained increase in the CD4+ cell count, as compared with antiretroviral therapy alone, interleukin-2 plus antiretroviral therapy yielded no clinical benefit in either study. (ClinicalTrials.gov numbers, NCT00004978 [ESPRIT] and NCT00013611 [SILCAAT study].)
85: Developmental and comparative immunology, 2009 Oct 9, 361(16)
Identification of the functional Interleukin-2 binding domain of the chicken common cytokine receptor gamma chain.
[Abstract]CD132 is the common gamma chain to a number of cytokine receptor complexes including that for IL-2. To identify the functional domain of chicken CD132 (chCD132), the cDNA of chCD132 was cloned, and a neutralizing monoclonal antibody, raised against a recombinant chCD132 protein, was identified by inhibition of IL-2-dependent proliferation of T cells. Flow cytometry analysis revealed that chCD132 molecules are expressed on the surface of splenic mononuclear cells. The functional domain of chCD132 that binds to chicken interleukin 2, Q(84)E(94)L(95)Q(96)N(97)L(98), was found through phage display and peptide-competitive ELISA, and its critical residue Q(96) was further identified. A tertiary structure model shows that the functional domain is positioned at the elbow-like junction of N- and C- terminal fibronectin-III domains of chCD132. These data provide experimental evidence for elucidating the interaction between chCD132 and chIL-2.
86: Biochemical and biophysical research communications, 2009 Oct 8, 361(16)
Interleukin-2 induces the activities of DNA topoisomerase I and DNA topoisomerase II in HuT 78 cells.
[Abstract]The induction by interleukin-2 of DNA topoisomerase I and DNA topoisomerase II activities in the human T cell line HuT 78 was investigated. HuT 78 cells were treated with 1000U of interleukin-2/ml, and extracts of the HuT 78 nuclei were prepared over a 24h period. The extracts were assayed quantitatively for the activities of DNA topoisomerase I and DNA topoisomerase II. Three concomitant, transient increases of 3- to 11-fold in the specific activities of both DNA topoisomerase I and DNA topoisomerase II were observed following treatment with IL-2 at 0.5, 4, and 10h after treatment with interleukin-2. The specific activities of both enzymes returned to base-line values after each of these transient increases. These results reveal that the activities of DNA topoisomerase I and DNA topoisomerase II are highly regulated in HuT 78 cells upon treatment with IL-2.
87: Journal of immunotherapy (Hagerstown, Md. : 1997), 2009 Nov-Dec, 32(9)
Engineered interleukin-2 antagonists for the inhibition of regulatory T cells.
[Abstract]The immunosuppressive effects of CD4 CD25 high regulatory T cells (Tregs) interfere with antitumor immune responses in cancer patients. Here, we present a novel class of engineered human interleukin (IL)-2 analogs that antagonizes the IL-2 receptor, for inhibiting regulatory T cell suppression. These antagonists have been engineered for high affinity to the alpha subunit of the IL-2 receptor and very low affinity to either the beta or gamma subunit, resulting in a signaling-deficient IL-2 analog that sequesters the IL-2 receptor alpha subunit from wild type IL-2. Two variants, "V91R" and "Q126T" with residue substitutions that disrupt the beta and gamma subunit binding interfaces, respectively, have been characterized in both a T cell line and in human primary Tregs. These mutants retain their high affinity binding to IL-2 receptor alpha subunit, but do not activate STAT5 phosphorylation or stimulate T cell growth. The 2 mutants competitively antagonize wild-type IL-2 signaling through the IL-2 receptor with similar efficacy, with inhibition constants of 183 pM for V91R and 216 pM for Q126T. Here, we present a novel approach to CD25-mediated Treg inhibition, with the use of an engineered human IL-2 analog that antagonizes the IL-2 receptor.
88: Journal of immunology (Baltimore, Md. : 1950), 2009 Oct 15, 183(8)
In vivo expansion of activated naive CD8+ T cells and NK cells driven by complexes of IL-2 and anti-IL-2 monoclonal antibody as novel approach of cancer immunotherapy.
[Abstract]IL-2 is potent imunostimulatory molecule that plays a key role in T and NK cell activation and expansion. IL-2 is approved by the FDA to treat metastatic renal cancer and melanoma, but its extremely short half-life and serious toxicities are significant limitations of its use. It was reported that in vivo biological activity of IL-2 can be increased by association of IL-2 with anti-IL-2 mAb (S4B6). IL-2/S4B6 mAb immunocomplexes were described to be highly stimulatory for NK and memory CD8(+) T cells and intermediately also for regulatory T cells. IL-2/JES6-1 mAb immunocomplexes are stimulatory solely for regulatory T cells. In this study we show that although both mentioned IL-2 immunocomplexes are less potent than free IL-2 in vitro, they possess extremely high stimulatory activity to expand activated naive CD8(+) T cells in vivo. IL-2 immunocomplexes expand activated naive CD8(+) T cells several hundred-fold times after four doses and more than 1000-fold times after six doses (1.5 microg/dose of IL-2), whereas free IL-2 given at the same dosage shows negligible activity. IL-2/S4B6 mAb immunocomplexes also induce massive expansion of NK cells (40% of DX5(+)NK1.1(+) cells in spleen). Importantly, activated naive CD8(+) T cells expanded by IL-2 immunocomplexes form robust population of functional memory cells. We also demonstrate in two distinct tumor models that IL-2/S4B6 mAb immunocomplexes possess considerable antitumor activity. Finally, by using radioactively labeled IL-2, we provide for first time direct evidence that IL-2 immunocomplexes have much longer half-life in circulation than free IL-2, being approximately 3 h vs <15 min, respectively.
89: Human gene therapy, 2010 Jan 27, 184(3)
Phase 1 Trial of Allogeneic Gene-modified Tumor Cell Vaccine RCC-26/CD80/IL-2 in Patients with Metastatic Renal Cell Carcinoma.
[Abstract]Abstract Preclinical studies showed that the allogeneic tumor cell line RCC-26 displayed natural immunogenic potential that was enhanced through expression of CD80 costimulatory molecules and secretion of interleukin-2. Here we report the study of RCC-26/CD80/IL-2 cells in a phase 1 vaccine trial of renal cell carcinoma patients with metastatic disease (mRCC). Fifteen patients of the HLA-A*0201 allotype, with at least one metastatic lesion, were included. Irradiated vaccine cells were applied in increasing doses of 2.5, 10, and 40 x 10(6) cells over 22 weeks. Primary study parameters included safety and toxicity. Sequential blood samples were analyzed by interferon-gamma enzyme-linked immunospot assays to detect tumor antigen-associated (TAA) effector cells. The vaccine was well tolerated and the designated vaccination course was completed in 9 of 15 patients. Neither vaccine-induced autoimmunity nor systemic side effects were observed. Delayed-type hypersensitivity skin reactions were detected in 11 of 12 evaluated patients and were particularly strong in patients with prolonged survival. In parallel, vaccine-induced immune responses against vaccine or overexpressed TAA were detected in 9 of 12 evaluated patients. No tumor regressions occurred according to RECIST (Response Evaluation Criteria in Solid Tumors) criteria; however, median time to progression was 5.3 months and median survival was 15.6 months, indicating substantial disease stabilization. We conclude that vaccine use was safe and feasible in mRCC. Clinical benefits were limited in these patients with advanced disease; however, immune monitoring revealed vaccine-induced responses against multiple TAAs in the majority of study participants. These results suggest that this vaccine could be useful in combination therapies and/or minimal residual disease.
90: Pediatric blood & cancer, 2009 Dec 15, 53(7)
Administration of high-dose interleukin-2 in a 2-year-old with metastatic melanoma.
[Abstract]Malignant melanoma is rare in pediatrics, and therapies for patients with disseminated disease have not been well studied. This report describes our experience with the use of high-dose interleukin 2 (aldesleukin, IL-2) in a 2-year-old child with metastatic melanoma and describes our approach for the administration of this agent to young patients.
91: Journal of virology, 2009 Nov, 83(22)
Novel role for interleukin-2 receptor-jak signaling in retrovirus transmission.
[Abstract]Human T-lymphotropic virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma, and it encodes a number of nonstructural proteins that are involved in virus replication and immune evasion. The viral protein p12 previously has been characterized to interfere with major histocompatibility complex class, ICAM-1, and ICAM-2 expression, and it activates STAT5. Using a previously established T-cell line immortalized with an HTLV-1 molecular clone deleted for p12, we assessed the role of p12 in regulating cellular growth and virus transmission. These cells were complemented for p12 expression by the transduction of a lentivirus vector expressing p12. We report that p12 conferred a selective growth advantage in vitro and increased the colony formation of human T cells in soft-agar assays. Consistently with previous studies, p12(-) and p12(+) cell lines produced similar amounts of virus particles released into the supernatant of cultured cells, although we found that p12 expression greatly enhanced virus transmission. Moreover, we found that interleukin-2 (IL-2) stimulation also increased HTLV-1 transmission whether p12 was expressed or not, and inversely, that the inhibition of Jak signaling significantly reduced HTLV-1 transmission. Intriguingly, IL-2/Jak signaling was not associated with changes in viral gene expression, viral RNA encapsidation, the maturation of the virus particle, cell-cell adherence, or Gag polarization and virological synapse formation. We do demonstrate, however, that IL-2 stimulation and p12 expression significantly increased the rate of syncytium formation, revealing a novel role for IL-2 signaling and Jak activation in HTLV-1 virus transmission.
92: Journal of experimental zoology. Part A, Ecological genetics and physiology, 2009 Nov 1, 311(9)
Implication of PKC isozymes in the release of biogenic amines by mussel hemocytes: effect of PDGF, IL-2, and LPS.
[Abstract]The innate immune system of marine mussels (Mytilus galloprovincialis) is operated by phagocytic cells termed hemocytes. Lipopolysaccharide (LPS), interleukin-2 (IL-2), or platelet-derived growth factor (PDGF) increase biogenic amine synthesis in these cells, and the enzymes Ca(2+)-independent protein kinase C (PKC) (p105/108) and Ca(2+)-dependent PKC (p60) are involved in these processes. Stimulation by PDGF induces a down-regulation process affecting the form p108 of the Ca(2+)-independent PKC. In addition, PDGF produces the increase of expression of p60 in the membrane fraction. IL-2 induces the disappearance of p108 from the membrane but does not affect the presence of p60 in cytosol or membrane. For its part, LPS activates exclusively p60 by a down-regulation mechanism. The ensemble of results suggests that each agonist starts a pathway that implicates the PKC isoenzymes that mediate the regulation of the activities dopa decarboxylase, dopamine beta-hydroxilase, and phenyletanolamine N-methyltranferase, which lead to different actions related to biogenic amine synthesis.
93: Cancer immunology, immunotherapy : CII, 2010 Mar, 59(3)
Lytic activity against primary AML cells is stimulated in vitro by an autologous whole cell vaccine expressing IL-2 and CD80.
[Abstract]Despite being of the myeloid lineage, acute myeloid leukaemia (AML) blasts are of low immunogenicity, probably because they lack the costimulatory molecule CD80 and secrete immunosuppressive factors. We have previously shown that in vitro stimulation of autologous peripheral blood mononuclear cells (PBMCs) with primary AML cells modified to express CD80 and IL-2 promotes proliferation, secretion of Th1 cytokines and expansion of activated CD8(+) T cells. In this study, we show that allogeneic effector cells (from a healthy donor or AML patients) when stimulated with IL-2/CD80 modified AML blasts were able to induce the lysis of unmodified AML blasts. Effector cells stimulated with IL-2/CD80AML blasts had higher lytic activity than cells stimulated with AML cells expressing CD80 or IL-2 alone. Similarly, AML patient PBMCs primed with autologous IL-2/CD80 AML cells had a higher frequency of IFN-gamma secreting cells and show cytotoxicity against autologous, unmodified blasts. Crucially, the response appears to be leukaemia specific, since stimulated patient PBMCs show higher frequencies of IFN-gamma secreting effector cells in response to AML blasts than to remission bone marrow cells from the same patients. Although studied in a small number of heterogeneous patient samples, the data are encouraging and support the continuing development of vaccination for poor prognosis AML patients with autologous cells genetically modified to express IL-2/CD80.
94: Genes and immunity, 2009 Dec, 10(8)
The PTPN22gain-of-function+1858T(+) genotypes correlate with low IL-2 expression in thymomas and predispose to myasthenia gravis.
[Abstract]Protein tyrosine phosphatase, non-receptor type 22 (PTPN22) inhibits T-cell activation and interleukin-2 (IL-2) production. The PTPN22(gain-of-function)+1858T(+) genotypes predispose to multiple autoimmune diseases, including early-onset (non-thymomatous) myasthenia gravis (MG). The disease association and the requirement of IL-2/IL-2 receptor signaling for intrathymic, negative T-cell selection have suggested that these genotypes may weaken T-cell receptor (TCR) signaling and impair the deletion of autoreactive T cells. Evidence for this hypothesis is missing. Thymoma-associated MG, which depends on intratumorous generation and export of mature autoreactive CD4(+) T cells, is a model of autoimmunity because of central tolerance failure. Here, we analyzed the PTPN22 +1858C/T single nucleotide polymorphism in 426 German Caucasian individuals, including 125 thymoma patients (79 with MG), and investigated intratumorous IL-2 expression levels. Unlike two previous studies on French and Swedish patients, we found strong association of PTPN22 +1858T(+) genotypes not only with early-onset MG (P=0.00034) but also with thymoma-associated MG (P=0.0028). IL-2 expression in thymomas with PTPN22 +1858T(+) genotypes (P=0.028) was lower, implying weaker TCR signaling. We conclude that the PTPN22(gain-of-function) variant biases towards MG in a subgroup of thymoma patients possibly by impeding central tolerance induction.
95: Biotechnology letters, 2009 Nov, 31(11)
Enhancing immune responses against SARS-CoV nucleocapsid DNA vaccine by co-inoculating interleukin-2 expressing vector in mice.
[Abstract]The immunogenicity of SARS-CoV nucleocapsid DNA vaccine and the immunoregulatory activity of interleukin-2 (IL-2) were investigated. DNA vaccine plasmids, pcDNA-N and pcDNA-IL2, were constructed and inoculated into BALB/c mice with or without pcDNA-IL2 by intramuscular injection. Cellular and humoral immune responses were assessed by indirect ELISA, lymphocyte proliferation assays, ELISPOT and FACS. The nucleocapsid DNA vaccine had good immunogenicity and can induce specific humoral and cellular immunity in BALB/c mice, while IL-2 plays an immunoadjuvant role and enhances specific immune responses. This study provides a frame of reference for the design of DNA vaccines against SARS-CoV.
96: Seminars in immunology, 2009 Dec, 21(6)
IL-2 and its high-affinity receptor: Genetic control of immunoregulation and autoimmunity.
[Abstract]Type 1 diabetes (T1D) is an organ-specific autoimmune disease featured by destruction of the insulin producing beta-cells of the pancreas by autoreactive T-lymphocytes. Putative environmental triggers conspire with a constellation of genetic elements scattered throughout the genome to elicit a multifactorial autoimmune response involving virtually every cell type of the immune system against pancreatic beta-cells. Recent highly powered genome-wide association studies have confirmed and identified fifteen chromosomal regions harboring several candidate T1D-associated gene loci. Here, we summarize what we know about the genetics of T1D with an emphasis on the contributions of mouse Il2 and human IL2RA polymorphisms and the IL-2-IL-2R pathway to autoimmunity and, more specifically, Treg development and function.
97: Clinical and experimental medicine, 2009 Dec, 9(4)
Interleukin-2 in CD8+ T cells correlates with Banff score during organ rejection in liver transplant recipients.
[Abstract]The aim of this study is to compare the histological grading of acute organ rejection according to the Banff score with intracellular interleukin-2 (IL-2) concentrations in cytotoxic CD8+ T cells from peripheral blood samples. 66 recipients after liver transplantation and 20 healthy controls were included into this study. Blood samples of liver transplant recipients were collected beside routine visits or, in case of suspected organ rejection, with additional liver biopsy. For cytometry, the blood cells were stained with CD3, CD8 and intracellular-IL-2. The percentage of cells with detectable intracellular IL-2 was significantly increased in patients with acute rejection (n = 7, P < 0.001, t Test) compared to recipients without rejection. The percentage of cells with detectable intracellular IL-2 (mean +/- SEM) was 7.6 +/- 0.9% in rejection patients, 2.3 +/- 0.22% in stable liver transplant recipients, and 14 +/- 2.99% in healthy controls. Intracellular IL-2 correlates to the Banff score in rejection patients (Spearmans-rho = 0.81, P < 0.05). This cytometric method shows a good sensitivity (71%) with a cut-off based on a high specificity of 95% for histological proven organ rejection in our study cohort. Measurement of intracellular IL-2 in cytotoxic CD8+ T-lymphocytes by flow cytometry correlates very well to the histological grading according to the Banff score and shows a good sensitivity and excellent specificity in acute organ rejection.
98: Cancer immunology, immunotherapy : CII, 2009 Oct, 58(10)
Human CD80/IL2 lentivirus transduced acute myeloid leukaemia cells enhance cytolytic activity in vitro in spite of an increase in regulatory CD4+ T cells in a subset of cultures.
[Abstract]Immunotherapeutic strategies are increasingly being explored as a method of enhancing anti-tumour immune responses in patients with acute myeloid leukaemia (AML). Regulatory CD4(+) T cells (Tregs) suppress effector T and natural killer (NK) cells and therefore pose a potential challenge to the efficacy of immunotherapy. AML cells transduced with a lentivirus expressing CD80 (B7.1) and IL2 (LV-CD80/IL2) are capable of stimulating T and NK cell cytotoxicity in vitro. This study examines the effect of CD80/IL2 modified AML cells on Treg number and function. We report a significant increase in the number of CD8(+) T cells (P = 0.046) CD3(-)CD56(+) NK cells (P = 0.028) and CD3(+)CD4(+)CD25(high)Foxp3(+) Tregs (P = 0.043) following stimulation for 7 days with allogeneic LV-CD80/IL2 AMLs. In contrast, autologous LV-CD80/IL2 AML cell cultures provide a weaker stimulation with a lower number of CD8(+) T cells (P = 0.011) and no change in NK cell or Treg numbers. However, an increase in cytotoxic CD8(+) T cells and NK cells are detected following both allogeneic and autologous LV-CD80/IL2 stimulation as demonstrated by an increase in IFN-gamma and CD107a expression. Despite the presence of increased numbers of Tregs with suppressive activity in a subset of cultures, increased lysis of unmodified AMLs was still achieved following allogeneic (day 0, 2.2%; day 7, 20.4%) and more importantly, autologous LV-CD80/IL2 culture in which AML patients had recently received intensive chemotherapy (day 0, 0%; day 7, 16%). Vaccination with LV-CD80/IL2 therefore provides a potential strategy to enhance anti-leukaemia immune responses without a concomitant stimulation of Treg-mediated inhibition of cytotoxic immunological responses.
99: Cancer biotherapy & radiopharmaceuticals, 2009 Feb, 24(1)
Activity of continuous infusion + pulse interleukin-2 with famotidine in metastatic melanoma.
[Abstract]High-dose interleukin-2 (IL-2), given via continuous intravenous (i.v.) infusion, induces lymphokine-activated killer (LAK) cell cytotoxicity against tumor cells. These LAKs exhibit enhanced cytotoxicity against tumor cells in vitro when they are subsequently pulsed with additional IL-2. Famotidine may increase LAK cytotoxicity against neoplastic cells by allowing for greater IL-2 uptake at the IL-2 receptor on lymphocytes. Twenty-three (23) patients received famotidine 20 mg i.v. twice per day and continuous-infusion IL-2 (18 MIU/m(2)/24 hours) for 72 hours, followed by a 24-hour rest, then 1-3 daily-pulse IL-2 doses of 18 MIU/m(2) over 15-30 minutes preceded by famotidine 20 mg i.v. Cycles were repeated every 3 weeks. The most common metastatic sites were lung, lymph node, and subcutaneous/soft tissue. The most common toxicities were fever, rigor, nausea/emesis, hypophosphatemia, hypotension, elevated creatinine, and pulmonary edema. There were no treatment-related deaths. One (1) complete (4%) and 9 partial responses (39%) were seen (43% total response rate; 95% confidence interval: 22%-65%). Median survival for all patients is 13 months. The combination of famotidine and high-dose continuous infusion + pulse IL-2 is active in metastatic melanoma.
100: Journal of immunotherapy (Hagerstown, Md. : 1997), 2009 Feb-Mar, 32(2)
Retrospective analysis of the safety and efficacy of interleukin-2 after prior VEGF-targeted therapy in patients with advanced renal cell carcinoma.
[Abstract]Agents targeting vascular endothelial growth factor (VEGF) signaling have been advocated as frontline therapy for advanced renal cancer. The role of interleukin 2 (IL-2) therapy after resistance to VEGF-targeted therapy remains unexplored. We conducted a retrospective analysis of the tolerability and efficacy of IL-2 therapy in patients who had previously received VEGF-targeted therapy. Twenty-three consecutive patients who received salvage IL-2 therapy were analyzed. Fifteen patients had received prior tyrosine kinase inhibitors (TKIs) (sorafenib or sunitinib), whereas 8 patients had received bevacizumab alone. Six of 23 patients did not receive week 2 of cycle 1 of treatment. All 6 of these patients had received prior TKIs. The incidence of severe cardiac toxicities, including 1 sudden cardiac death, in patients receiving prior TKI was 40% (95% confidence interval, 16.3-67.7%), significantly higher than what is expected from historical experience. Only 1 of 23 patients proceeded to receive a second cycle of IL-2. No patients achieved a partial or complete response to therapy. This retrospective analysis highlights unexpected and severe cardiac toxicities in patients receiving IL-2 after VEGF-targeted TKI therapy. The assumption that IL-2 therapy can be safely administered after TKI therapy may not be valid. Further examination of the safety of this sequential approach is necessary and more cautious patient selection seems warranted.
101: Urologic oncology, 2010 May-Jun, 28(3)
Disparities in the treatment of patients with IL-2 for metastatic renal cell carcinoma.
[Abstract]OBJECTIVES: The incidence of metastatic renal cell cancer (mRCC) is rising. To date, interleukin-2 (IL-2) is the only treatment offering a complete response rate for mRCC. We wish to test the hypothesis that the combination of restricted availability and expense associated with IL-2 administration results in differential access to the medication based on race and sex, despite similar clinical indications for its use. METHODS: We used data from the Surveillance, Epidemiology, and End Results program and the Centers for Medicare Services (CMS) to clinically characterize subjects with mRCC diagnosed from 1992 through 2002. We linked these subjects to claims identified in the CMS databases. We then assigned subjects to cohorts receiving radical nephrectomy, IL-2, both, or neither. A logistic model was created to identify factors that had significant independent effects on the receipt of IL-2. RESULTS: Three thousand seven hundred thirty individuals were identified with mRCC. After controlling for other variables, female subjects were less likely to receive IL-2 (O.R. 0.80). African American subjects were also less likely to receive IL-2 (O.R 0.55). Married individuals were much more likely to receive IL-2 (O.R 1.9). CONCLUSIONS: African Americans and women were much less likely to be treated with IL-2 after controlling for relevant clinical variables. These data document that the only therapy offering a complete response to patients with mRCC is less frequently given to those who are African American or female. It is possible that the racial and gender-based disparities in treatment with IL-2 will be replicated with newer, expensive treatment options for mRCC. Further prospective investigation into mitigating barriers to receipt of effective care for mRCC is urgently needed.