Abstract: Schistosomiasis is a chronic helminthic disease that affects about two hundred millions of people in the world. The pathogenesis of schistosome infection is primarily due to hepatic and intestinal granuloma formation around deposited eggs and subsequent fibrosis. It is known that CD4+ T cell subsets play critical roles in the host immunity and immunopathogenesis to schistosome infections， in which T helper 1 （Th1） and Th2 cells are major effector T cell subsets， whereas T regulatory （Treg） cells exert immunosuppressive roles in general. The recently discovered Th17 cells are also actively involved in the immune responses to the infection. During the infection， these T cell subsets cross?talk and exhibit different kinetics and roles in the control and regulation of infection progress and fibrosis. This review summarizes current findings of Th1， Th2， Th17 and Treg cells and their effector cytokines in schistosome infection.

Key words: Schistosome； Fibrosis； CD4+ T cell； Th17 cell； Treg cell

摘要： 血吸虫病是一种主要以肝、肠虫卵肉芽肿和随之伴随的纤维化为主要特征的免疫病理性疾病。一般认为，CD4+ T细胞亚群在抗血吸虫感染及免疫调控过程中起着重要作用。其中辅助性T（T helper，Th）细胞1（Th1）、2（Th2）是主要的效应性CD4+ T细胞亚群，而调节性T（Regulatory T，Treg）细胞在血吸虫感染免疫病理机制中总体起免疫下调作用，新近发现的Th17细胞也积极参与抗血吸虫免疫反应。随着血吸虫感染的进展，这4种CD4+ T细胞亚群数量及功能呈现不同变化趋势，但均对血吸虫感染发生、发展及纤维化病理进程起重要的调控作用。此外，这些CD4+ T细胞亚群之间也存在复杂的相互调节（Cross?talk）。本文就血吸虫感染过程中Th1、Th2、Th17 和 Treg细胞亚群及其效应细胞因子的动态变化与功能的研究进展作一综述。

关键词: 血吸虫；纤维化；CD4+ T细胞；Th17细胞；调节性T细胞