Inhibition of Th 17 Cells Regulates Autoimmune Diabetes in NOD Mice

摘要

Objective-The T helper 17 (Thl7) population, a subset of CD4-positive T-cells that secrete interleukin (IL)-17, has been implicated in autoimmune diseases, including multiple sclerosis and lupus. Therapeutic agents that target the Thl7 effector molecule IL-17 or directly inhibit the Thl7 population (IL-25) have shown promise in animal models of autoimmunity. The role of Thl7 cells in type 1 diabetes has been less clear. The effect of neutralizing anti-IL-17 and recombinant IL-25 on the development of diabetes in NOD mice, a model of spontaneous autoimmune diabetes, was investigated in this study.rnRESEARCH DESIGN AND METHODS AND RESULTS-rnAlthough treatment with either antHL-17 or IL-25 had no effect on diabetes development in young (<5 weeks) NOD mice, either intervention prevented diabetes when treatment was started at 10 weeks of age (P < 0.001). Insulitis scoring and immunofluo-rescence staining revealed that both anti-IL-17 and IL-25 significantly reduced peri-islet T-cell infiltrates. Both treatments also decreased GAD65 autoantibody levels. Analysis of pancreatic lymph nodes revealed that both treatments increased the frequency of regulatory T-cells. Further investigation demonstrated that IL-25 therapy was superior to anti-IL-17 during mature diabetes because it promoted a period of remission from new-onset diabetes in 90% of treated animals. Similarly, IL-25 delayed recurrent autoimmunity after syngeneic islet transplantation, whereas anti-IL-17 was of no benefit. GAD65-specific ELISpot and CD4-positive adoptive transfer studies showed that IL-25 treatment resulted in a T-cell-mediated dominant protective effect against autoimmunity.rnCONCLUSIONS-These studies suggest that Thl7 cells are involved in the pathogenesis of autoimmune diabetes. Further development of Thl7-targeted therapeutic agents may be of benefit in this disease.