Regulatory natural killer T cells protect against spontaneous and recurrent type 1 diabetes.

Autoimmune diseases, especially type 1 diabetes (T1D), may be caused by dysregulation of the immune system, which leads to hyporesponsiveness of regulatory T helper 2 (Th2) cells and promotion of autoimmune Th1 cells. Natural killer T (NKT) cells, which comprise a minor subpopulation of T cells, play a critical role in immunoregulation as a result of a rapid burst of IL-4 and IFN-gamma secretion. These cells are functionally and numerically deficient in individuals at risk of T1D, as well as in nonobese diabetic (NOD) mice.