Cross-talk between hepatic stellate cells and T lymphocytes in liver fibrosis

Fibrosis results from inflammation and healing following injury. The imbalance between extracellular matrix (ECM) secretion and degradation leads to the ECM accumulation and liver fibrosis. This process is regulated by immune cells. T lymphocytes, including alpha beta (αβ) T cells, which have adaptive immune functions, and gamma delta (γδ) T cells, which have innate immune functions, are considered regulators of liver fibrosis. This review aimed to present the current understanding of the cross-talk between T lymphocytes and hepatic stellate cells (HSCs), which are the key cells in liver fibrosis.The keywords "liver fibrosis", "immune", and "T cells" were used to retrieve articles published in PubMed database before January 31, 2020.The ratio of CD8+ (suppressor) T cells to CD4+ (helper) T cells is significantly higher in the liver than in the peripheral blood. T cells secrete a series of cytokines and chemokines to regulate the inflammation in the liver and the activation of HSCs to influence the course of liver fibrosis. In addition, HSCs also regulate the differentiation and proliferation of T cells.The cross-talk between T cells and HSCs regulates liver fibrosis progression. The elucidation of this communication process will help us to understand the pathological process of liver fibrosis.