NOD Mice with High Incidence of Type 1 Diabetes are not T Lymphocytopenic

An autoimmune pathogenesis has been indicated in insulin-dependent (type 1) diabetes mellitus (IDDM). Previously we reported that non-obese diabetic (NOD) mice as an animal model of spontaneously developing IDDM were immunologically characterized by T lymphocytopenia and impaired cellular immunities. The cumulative incidence of diabetes in the T lymphocytopenic female NOD mice was 10-20% by 24 weeks of age. On the other hand, the incidence of diabetes are 80-90% in the female NOD/Shi-Sendai (S), in whom proportion of lymophocyte subsets has not been known yet. Therefore, we examined the spleen cells of female NOD/Shi-S and female NOD/Shi with high incidence of diabetes, and of female Jcl : ICR as a control. Cell numbers, populations of T cells (Thy 1.2⁺, Lyt-1⁺ and Lyt-2⁺), B cells (surface-Ig⁺), NK cells (acialo GM₁⁺) and responsiveness to Concanavalin A were analyzed as immunological parameters. In contrast to the T lymphocytopenic NOD, these immunological parameters were not impaired in the NOD/Shi-S and NOD/Shi in comparison to those of Jcl : ICR. The results indicate that there may be a positive association between the incidence of diabetes and T cell number and functions in female NOD mice.