NOD dendritic cells stimulated with Lactobacilli preferentially produce IL-10 versus IL-12 and decrease diabetes incidence.

Dendritic cells (DCs) from NOD mice produced high levels of IL-12 that induce IFNγ-producing T cells involved in diabetes development. We propose to utilize the microorganism ability to induce tolerogenic DCs to abrogate the proinflammatory process and prevent diabetes development. NOD DCs were stimulated with Lactobacilli (nonpathogenic bacteria targeting TLR2) or lipoteichoic acid (LTA) from Staphylococcus aureus (TLR2 agonist).

Decreased frequencies of CD4+CD25+Foxp3+ cells and the potent CD103+ subset in peripheral lymph nodes correlate with autoimmune disease predisposition in some strains of mice.

The CD4(+)CD25(+)Foxp3(+) cells are essential for regulation of the immune response, and the integrin, CD103 (α(E)β(7)), identifies a potent subset of these cells. Defects in CD4(+)CD25(+)Foxp3(+) cells are thought to contribute to susceptibility to autoimmune disease in predisposed individuals. Studies evaluating the quality and quantity of CD4(+)CD25(+)Foxp3(+) regulatory cell populations in the context of autoimmune disease susceptibility have been inconclusive, and few if any, have analyzed the CD103 subset.

APC activation restores functional CD4(+)CD25(+) regulatory T cells in NOD mice that can prevent diabetes development.

Background: Defects in APC and regulatory cells are associated with diabetes development in NOD mice. We have shown previously that NOD APC are not effective at stimulating CD4(+)CD25(+) regulatory cell function in vitro. We hypothesize that failure of NOD APC to properly activate CD4(+)CD25(+) regulatory cells in vivo could compromise their ability to control pathogenic cells, and activation of NOD APC could restore this defect, thereby preventing disease.

Deficiency in NOD antigen-presenting cell function may be responsible for suboptimal CD4+CD25+ T-cell-mediated regulation and type 1 diabetes development in NOD mice.

Various defects in antigen-presenting cells (APCs) and T-cells, including regulatory cells, have been associated with type 1 diabetes development in NOD mice. CD4(+)CD25(+) regulatory cells play a crucial role in controlling various autoimmune diseases, and a deficiency in their number or function could be involved in disease development. The current study shows that NOD mice had fewer CD4(+)CD25(+) regulatory cells, which expressed normal levels of glucocorticoid-induced tumor necrosis factor receptor and cytotoxic T-lymphocyte-associated antigen-4.