Strikingly, while IFN-γ production was suppressed potently, an increase in IL-17+ T cells was observed [84]. These

data suggest that Th17 and Th1 cells may differ in their susceptibility to Treg-mediated suppressive signals. The pivotal influence of Tregs in determining whether a pathological autoimmune response develops following immune challenge was confirmed using Treg depletion and reconstitution strategies in various induced models of organ-specific autoimmune disease, including collagen-induced arthritis (CIA) [85] and experimental see more autoimmune encephalomyelitis (EAE) [44,86–88]. In these models depletion of Tregs was associated with more vigorous immune responses and particularly increased

levels of IFN-γ production [87], illustrating that Tregs suppress Th1 responses effectively which, at the time, were considered the driving force in these models. An elegant series of experiments dissecting the comparative roles of IL-12 and IL-23 in promoting autoimmunity prompted a dramatic change in emphasis, highlighting the pathogenic roles of IL-23 in promoting the expansion of IL-17-producing effector T cells and their critical importance in autoimmune inflammation [89,90]. Most studies using anti-CD25-mediated Treg depletion strategies were carried out before the implications of these studies www.selleckchem.com/products/dabrafenib-gsk2118436.html were realized fully. However, there is evidence that Tregs suppress production of both Th1 and Th2 responses in models of arthritis [91], and that Treg depletion heightens production of IL-17 and IL-6 (both associated with Th17 responses) as well as IFN-γ during EAE [92]. Thus, it appears that Tregs have at least some capacity to hold the development of Th17 responses, as well as Th1 and Th2 responses, in check. Most models of organ specific autoimmunity are associated with definitively

Cyclin-dependent kinase 3 polarized immune responses. Unusual in this respect is autoimmune gastritis (AIG), which can be induced by Th1-, Th2- or Th17-polarized CD4+ T cells. Pathology in AIG is orchestrated by CD4+ T cells recognizing the alpha chain of the H+K+adenosine triphosphatase (ATPase) expressed in gastric parietal cells [93]. Disease can be induced in immunodeficient nude mice by transfer of antigen-specific transgenic T cells and this can be suppressed by the co-transfer of Tregs[94]. It has now been shown that while Th1, Th2 and Th17 polarized populations can all induce AIG, they differ in their pathogenicity and in their susceptibility to suppression. Th1 cells appear to be those suppressed most easily by freshly explanted polyclonal Tregs, while Th2 cells were slightly less well controlled [95].