We hypothesized that ppins designer antigens that do not induce CD8+ T cells and autoimmune diabetes in H-2b RIP-B7.1 tg mice also do not induce autoreactive CD8+ T cells in NOD mice, expressing the diabetes-susceptible H-2g7 haplotype (Kd, Db; I-Ag7) but elicit a tolerogenic immunity that could suppress spontaneous diabetes development in these mice. The gene discussed is CD80; the disease is diabetes mellitus.