3b). The phenotype and frequency of these populations of B cells from the BALB/c, SAMP1/Yit and AKR/J strains were found to be similar. The TGF-β1 appears in two physiological forms: bioactive and inactive. In the present system, the majority of TGF-β1 assessed was either solely inactive or latent. We also measured the active form of TGF-β1; however, the amount was too low to determine any effects of TLR ligands on its secretion. Moreover, of the two immune-modulatory cytokines (IL-10 and TGF-β), TLR responses, especially by CpG-DNA ligation, for IL-10 production from the B cells was more striking CP-673451 than that for TGF-β. Therefore, the present

findings mainly highlight the intriguing role of IL-10, rather than that of TGF-β. B cells are widely considered to play pathogenic roles in click here adaptive immune responses through antibody production and effector T-cell activation, which leads to the development of various autoimmune diseases. In addition to the pathogenic role of conventional B cells, a subset of B cells that

negatively regulates autoimmunity and inflammation has also been reported.32–35 The regulatory role of B cells was initially demonstrated in mice with experimental autoimmune encephalitis (EAE), which indicated that B-cell deficiency exacerbates disease outcome and severity, and EAE model mice did not fully recover from the disease compared with wild-type mice.43–45 Recent studies confirmed HSP90 that the regulatory contribution of B cells during EAE was dependent on their IL-10 production ability.46,47 B cells function as negative regulators of immune responses and have also been

studied in a variety of experimental autoimmune models with rheumatoid arthritis,30,48 lupus,49 non-obese diabetes50 and skin diseases.51 The regulatory B-cell subset is therefore currently considered to be a key cell population for modulation of the immune system. Critical roles of regulatory B cells have been reported in recent studies that used a variety of experimental inflammatory bowel disease models. Chronic colitis in T-cell receptor α knockout (TCR-α KO) mice resembles human ulcerative colitis and its pathogenesis is associated with autoantibody production mediated by pathogenic B cells.52,53 Mizoguchi et al.54 also reported that B-cell-deficient TCR-α double KO mice develop more severe intestinal inflammation, indicating that the regulatory subset of B cells contributes to suppression of TCR-α KO-mediated colitis. In another experiment, evaluations of G protein α inhibitory subunit (Gαi2) KO mice showed that disorders of a Gαi2-dependent process in the maturation of IL-10-producing B cells were associated with a mechanism for inflammatory bowel disease susceptibility.