Hematopoietic cell–derived interferon influenced autoimmune diabetes. (A) WT and irf7^−/− mice were treated with 500 μg poly(I:C) intravenously. After 24 hours, MHC I expression was analyzed in the pancreas. One of 3 representative stainings is shown. (B) BM chimeras (WT-BM > RIP-GP, irf7^−/−-BM > RIP-GP) were infected with 200 PFU LCMV-WE. On day 8, pancreatic β-islets were analyzed for expression of MHC I and infiltration of CD8⁺ T cells. One of 3 representative stainings is shown. (C) BM chimeras (WT-BM > RIP-GP, irf7^−/−-BM > RIP-GP) were infected with 200 PFU LCMV-WE. Blood glucose levels were analyzed in the blood (n = 4-5).