Essential roles of insulin expression in Aire+ tolerogenic dendritic cells in maintaining peripheral self-tolerance of islet β-cells

► Insulin expression in BM-derived thymic APCs is not essential for central tolerance of β-cells. ► Insulin expression in the spleen is restricted to Aire+CD11intB220+Gr1+ DCs. ► Insulin deletion in CD11c+ DCs induces increased insulitis in B6g7 mice. ► Peripheral insulin expression plays a role in maintaining β-cell tolerance.