Furthermore, it may not be surprising that relative reduction of gene expression was seen at the early stages studied here, at which time tolerance would be induced. Of note, tolerance to self antigens requires the activation of self-reactive lymphocytes and their elimination by apoptosis as a result of this activation. Furthermore, elimination of self-reactive lymphocytes in the periphery also requires Etoposide chemical structure activation of the regulatory mechanisms (such as regulatory T cells). Thus, both central and peripheral tolerances are active processes that require normal mitochondrial and metabolic function. Our gene Ontology and KEGG Pathway analyses

(Table 5 and Table 6), together with the leukocyte study [25], provided evidence for defects in mitochondria, metabolism, antigen processing/presentation and T cell activation/function Selleckchem Luminespib and immune response. Furthermore, our preliminary functional studies investigating the mitochondrial/metabolic defect found impaired mitochondrial potential in NOD spleen leukocytes. All these data, together with the literature discussed above, support the idea of a global immune repression, which may lead to the breakdown of self-tolerance in autoimmune diabetes. Indeed, a recent study, using a mouse model of spontaneous autoimmune arthritis [44], suggested that

efficient suppression of autoimmune diseases requires polyclonal regulatory T cell specificities rather than single antigen-specificities. Thus, we propose Amylase the following hypothesis. A genetic defect in metabolism/mitochondria results in a global repression of the immune system leading to a deficiency in immune tolerance, thus predisposing NOD mice to autoimmunity. Analysis of changes in gene expression and molecular pathways in NOD mice between different ages will shade further light on the

defects that directly accompany initiation of insulitis, and subsequently development of diabetes. Furthermore, the defects in antigen presenting cells (such as B cells, macrophages and dendritic cells) may synergize with defects in the regulatory and effector T-cells to create dyshomeostasis in the early stages of autoimmune diabetes. Thus, investigation of the APC cell subsets is also warranted to provide a more comprehensive picture of the molecular pathophysiology of autoimmune diabetes. The promoter and molecular pathway analyses (Table 7 and Table 8) identified several factors that may play a role in regulating the above discussed defect. Several of these factors (Hnf4a, Ifng, Trp53, Myc, IL15, Tnf, Tgfb1, beta-estradiol, IL6 and Ar) were also identified by the spleen leukocyte study [25] indicating a strong involvement of the CD4 T-cells in the unfractionated immune cells.