PREVENTION OF DIABETES IN NONOBESE DIABETIC MICE BY TUMOR NECROSIS FACTOR (TNF) - SIMILARITIES BETWEEN TNF-ALPHA AND INTERLEUKIN-1

The role of tumor necrosis factor α (TNF-α) in the pathogenesis of autoimmune diabetes mellitus was tested in the nonobese mouse (NOD) model system. The effects of TNF-α were assessed on three levels: (i) insulitis development, (ii) development of overt diabetes, (iii) adoptive transfer of diabetes by splenic lymphocytes. Spontaneous diabetes mellitus was blocked in NOD mice by long-term treatment with recombinant TNF-α. Treatment with TNF-α caused a significant reduction in the lymphocytic infiltration associated with the destruction of the insulin-producing beta cells. Class II major histocompatibility complex la expression by islet cells was not up-regulated by TNF-α. Moreover, TNF-α was able to suppress the induction of diabetes in adoptive transfer of lymphocytes from diabetic female mice to young nondiabetic male NOD mice. These activities of TNF-α were shared by interleukin 1α in this system. These studies have implications for the pathogenesis and therapy of autoimmune diabetes mellitus.