This study is aimed at examining the potential role of regulatory T- (Treg-) Th1-Th17-Th22 cells in the pathogenic process of autoimmune hepatitis (AIH). The numbers of Foxp3+Tregs and Th1, Th17, and Th22 cells were measured in 32 AIH patients using flow cytometry. Moreover, a murine model of experimental autoimmune hepatitis (EAH) was also established and used to investigate the function of Treg-Th1-Th17-Th22 cells in disease progression. AIH patients undergoing an active state had significantly decreased numbers of CD3+CD4+CD25+Foxp3+Tregs and increased numbers of CD3+CD4+CD25−Foxp3+T, CD3+CD4+IFN-γ+Th1, CD3+CD4+IL-17+Th17, and CD3+CD4+IL-2+Th22 cells as well as higher levels of Th1/Th17/Th22-type cytokines compared to AIH patients in remission and HC. Additionally, the numbers of CD3+CD4+CD25+Foxp3+Tregs were negatively correlated with the numbers of Th1-Th17-Th22 cells. Also, the serum levels of IL-17A and IL-22 were correlated positively with liver injury (ALT/AST), whereas the serum levels of IL-10 were correlated negatively with hypergammaglobulinaemia (IgG, IgM) in AIH patients. Interestingly, the percentages of spleen Tregs, expression of Foxp3 mRNA, and liver IL-10 levels decreased, whereas the percentages of spleen Th1-Th17-Th22 cells, expression of T-bet/AHR/RORγt mRNA, and liver IFN-γ, IL-17, and IL-22 levels increased in the murine model of EAH. Our findings demonstrated that an imbalance between Tregs and Th1-Th17-Th22 cells might contribute to the pathogenic process of AIH.

Follicular helper T (TFH) cell provides germinal centre (GC) B cell with critical signals for autoantibody production in the immunopathogenesis and progression of autoimmune hepatitis (AIH). However, the immunoregulatory functions of follicular regulatory T (TFR) cell in AIH are still unclear. The numbers of circulating TFR/ TFH cells were measured in AIH patients. Moreover, we established experimental autoimmune hepatitis (EAH) model to examine the function of TFR cells on B-cell differentiation and autoantibody production in vivo and vitro. AIH patients had significantly increased numbers of TFH cells and decreased numbers of TFR cells as well as imbalanced TFR/TFH-type cytokines (IL-10, TGF-β1 and IL-21) compared with healthy controls (HCs). In addition, TFR cell numbers negatively correlated with TFH cell numbers. Also, serum hypergammaglobulinaemia (IgG and IgM) concentrationnegatively correlated the levels of serum IL-21, but positively correlated with the levels of serum IL-10 in AIH patients. Furthermore, in comparison with control group, significantly higher frequencies of spleen TFR cells but lower frequencies of spleen TFH cells were detected in the EAH group. Further analysis found that TFR cells simultaneously express the phenotypic characteristics of Treg and TFH cells, but exercise as negative regulators of autoantibody production in vitro culture. Our findings demonstrated that dysregulated between TFR and TFH cells might cause excessive production of autoantibodies and destruction of the immune homeostasis, leading to the immunopathological process in AIH.

This study investigated the role of IL-33 in the pathogenesis of autoimmune hepatitis (AIH). The levels of IL-33/sST2 and Th1/Th2/Th17-type cytokines were determined by enzyme-linked immunosorbent assay in serum samples obtained from 30 AIH patients and 20 healthy controls (HCs). In addition, a murine model of experimental AIH (EAIH) was established to investigate the role of IL-33 in disease progression. The serum levels of IL-33, sST2, Th17 cytokines (IL-17A), Th1 cytokines (IFN-γ, TNF-α), and Th2 cytokines (IL-4) were significantly elevated in AIH patients compared to HCs. Following immunosuppression therapy, serum levels of IL-33 and sST2 were significantly decreased. Additionally, the serum levels of IL-33 in AIH patients were correlated positively with markers of hypergammaglobulinemia (IgG, IgM, and IgA) and liver injury (γ-GT/ALP). Also, the serum levels of IL-33 in AIH patients were correlated positively with proinflammatory cytokine levels (IL-17A and IL-4). Interestingly, treatment of EAIH mice with a specific IL-33 neutralizing antibody significantly reversed the increasing trend in serum ALT/AST and inhibited the production of the type 2 (IL-4) and type 17 cytokines (IL-17) but not the type 1 cytokine (IFN-γ). Our findings highlight the possible role of the IL-33/sST2 axis in the progression of AIH, opening a new door for developing a novel therapeutic strategy for AIH.