B and Th1 memory lymphocytes accumulate in the pancreas of NOD.Igμnull mice following B cell reconstitution. A) Flow cytometry analyses of pancreas infiltrating lymphocytes in diabetic animals (between 20 and 30 weeks post-reconstitution) demonstrated an accumulation of CD19+ B cells (74%). T cells accumulate preferentially in pancreatic nodes (73%) and spleen (50%). Data represent 1 of 3 separate experiments with 2-4 animals per group. B) The majority of T cells found infiltrating the pancreas expressed memory marker CD44high (80% of CD8+ and 50% of CD4+ respectively). C) Pancreas infiltrating lymphocytes were in vitro stimulated with anti-CD3/CD28 beads and 5-day supernatants were screened by cytokine bead assays (average and SD of 3 animals).