IL‐35: A potential therapeutic target for controlling hepatitis B virus infection

Xiang, Xiao Gang; Xie, Qing

Interleukin (IL)‐35, a recently identified cytokine of the IL‐12 family, is a potent immunosuppressive cytokine secreted by regulatory T (Treg) cells and the newly reported regulatory B (Breg) cells. IL‐35 functions as a crucial immunosuppressive factor in immune‐mediated diseases, and the predominant mechanism of suppression is its ability to suppress T cell proliferation and effector functions. The pathogenic processes of the non‐cytopathic hepatitis B virus (HBV) infection‐related liver diseases are immune‐mediated, including liver damage and viral control. It has been found that IL‐35 is detectable in peripheral CD4(+) T cells in chronic HBV‐infected patients, whereas it is undetectable in healthy individuals. There is growing evidence that cytokine‐mediated immune responses play a pivotal role in determining the clinical outcome during HBV infection. It is particularly important to investigate the effects of IL‐35 in the immunopathogenesis of chronic HBV infection. In this study, the recent understanding of this issue is discussed.