Immunobiology of DC in NOD mice.

NOD mice spontaneously develop diabetes between 15 and 20 weeks of age, which is preceded by insulitis characterized by the infiltration of lymphocytes. Dendritic cells (DC) are among the first cells to infiltrate the islet and they have been implicated in the pathogenesis of the disease. Our work has been concerned with the detailed characterization of four distinct DC populations in NOD mice: two derived from bone marrow (BM) cells cultured in either granulocyte-macrophage colony-stimulating factor (GM-CSF) plus interleukin-4 (IL-4) or GM-CSF alone and two from the spleen of Flt3 ligand (Flt3L) -treated mice, isolated on the basis of CD8alpha expression. Phenotypic and functional differences between these DC subsets in NOD mice have been identified. In addition, we obtained a lower yield of NOD BM-derived DC and they expressed higher levels of cell-surface CD40 and IL-12 p40 mRNA than BM-derived DC from the diabetes-resistant strain, B10.BR. We have also investigated the ability of these DC populations to modulate the development and progression of diabetes in NOD mice.