Th17细胞与肝脏疾病的研究进展

Research development of Th17 cells and liver diseases

机体免疫系统是抵抗外来病原体和各种损害的防御系统，根据CD4^＋T细胞的功能经典地分为辅助性T细胞（Th1、Th2）、细胞毒性T细胞以及调节性T细胞（Treg）3个亚群。Th1介导细胞免疫，Th2介导体液免疫，而Treg则在维护机体免疫平衡中发挥重要作用。然而随着对自身免疫性疾病的研究，发现一群不同于Th1、Th2、Treg的新型CD4^＋T细胞亚群——Th17细胞。已证实Th17细胞与清除胞外病原体、炎症、自身免疫性疾病和肿瘤的发生发展有密切联系。随着人们对肝炎、肝纤维化和肝癌等肝病认识不断加深，这种新型的Th17细胞在这些疾病中发生发展的作用机制也不断的被研究者所关注。

Immune system is a defensive system to resist external pathogens and various damages. According to the classical function, CD4^＋ T cells could be classified as Th1, Th2, and Treg cells. Thl cells dominate in cellular immunity while Th2 cells do in humoral immunity. However, Treg cells play important roles in maintaining the homeostasis of immune system. With the development of recent research in autoimmune diseases, Th17 cells have been identified as a new lineage of the effector Th cells which were unlike Thl, Th2, and Treg cells. It has been confirmed that Th17 cells play the key roles in removing of extracetlular pathogens, inflammation, autoimmune diseases, and cancers. Recently, more interests prompted researchers to have more ideas in the mechanism of liver disedses, such as hepatitis, fibrosis, and liver cancer about Th17 cells. This review summarizes the development of Th17 cells in liver diseases, and gives some new clues for studying the immune mechanism of liver diseases.