Interferon-tau inhibits the development of diabetes in NOD mice

Abstract

Interferon-alpha (IFN-α) inhibits the development of diabetes in animal models of autoimmune diabetes. However, the mechanism of the action is not fully understood and drug toxicity could limit its potential clinical utility. Interferon-tau (IFN-τ) is another type 1 interferon, which has less toxicity but may have different biologic activity than IFN-α. This study explores the effect of IFN-τ on the diabetic process in non-obese diabetic (NOD) mice. IFN-τ by intraperitoneal, subcutaneous, or oral routes of administration decreased the development of spontaneous diabetes in NOD mice. Islet inflammation was decreased 50%. IFN-τ administration to recipient mice prevented the development of passively transferred and cyclophosphamide accelerated diabetes. IFN-τ treatment also decreased anti-islet effector activity of NOD splenic cells. Immunoregulatory activity of splenic cells was augmented by IFN-τ administration as was the number of splenic CD25+CD4+ cells. Concanavalin A (Con A)-induced release of IFN-γ was decreased in spleen cells from IFN-τ treated mice. In conclusion, IFN-τ inhibits spontaneous autoimmune diabetes and passively transferred diabetes in the NOD mouse. This diabetes sparing activity may be due to an induction of regulatory cells, possibly CD25+CD4+ T cells, which in turn inhibit anti-islet effector cell activity and the development of insulitis and diabetes. Due to the lower drug toxicity, IFN-τ could be a better drug candidate than IFN-α for experimental clinical trials.