Genetic requirements for acceleration of diabetes in non-obese diabetic mice expressing interleukin-2 in islet beta-cells.

Diabetes was dramatically accelerated in non-obese diabetic (NOD) transgenic mice that expressed interleukin-2 (IL-2) in their beta cells. A single cross to C57BL/6 completely prevented this effect and a further backcross to the NOD genetic background showed that at least two diabetes susceptibility loci (Idd1s and Idd3/10s) were required for the diabetes acceleration T cells activated to islet antigens were not circulating in the mice. The accelerating effect of IL-2 was present; but decreased, in NOD mice that lacked CD8+ T cells as well as in NOD SCID mice. The implications are that in the NOD genetic background, the production of cytokines, such as IL-2, by islet-specific CD4+ T cells can lead to beta cell damage and diabetes and that CD8+ T cells may have a role in accelerating diabetes onset.