Th2／Th17细胞群与支气管哮喘机制研究

支气管哮喘（简称哮喘）是一种由多种细胞（如嗜酸粒细胞、肥大细胞、T淋巴细胞、中性粒细胞和气道上皮细胞等）和细胞组分参与的气道慢性炎症性疾病。经典的Th1／Th2细胞失衡被认为是过敏性哮喘的主要发病机制，Th17／IL-17轴被证实与重症哮喘、激素抵抗型哮喘、以中性粒细胞浸润为主的哮喘有关。近年来研究发现，机体内存在一种不同于目前已知的Thl、Th2、Thl7、Th9等的新型CD4＋T细胞，被称为Th2／Th17双表型记忆性CD4＋T细胞群（简称Th2／Th17细胞群）。在哮喘发病机制的探讨中发现，Th2／Th17细胞群既能分泌Th2表型细胞因子IL-4、IL-5、IL-13，也可以分泌Th17型细胞因子IL-17、IL-8、IL-22等；且在不同的微环境下发生不一样的生物学效应，这显示了Th2／Th17细胞群可能在哮喘发生发展（特别是重症哮喘）及各亚型相互转化过程中起着决定性作用。现就Th2／Th17细胞群的生物学功能及其与哮喘的相关性进行如下综述。

The mechanism research of Th2/Th17 cells and bronchial asthma

Bronchial asthma（asthma） is a kind of chronic airway inflammatory diseases mediated by eosinophils, mast cells, T lymphocytes, neutrophils, airway epithelial cells and their cytokinesD. Classic imbalance of ThI-Th2 cell played an important role in allergic asthma pathogenesis,Th17/IL-17 axis was confirmed with sever asthma, hormone resistant asthma, predominantly neutrophils infiltrating asthma. In recent years, the study found there is a a new subset of CD4＋ T cells in the body which is different from Thl,Th2, Thl7, Th9, called the Th2/Thl7 double phenotypic effector CD4＋ T cells （Th2/Th17 ceils）. Found in the discussion to the pathogenesis of asthma, Th2/Th17 ceils can both secrete Th2 cytokines IL-4, IL5, IL-13 and Th17 cytokines IL 17, IL-8, IL-22, etc. And under the different environment,it can produce different biological effect. This shows the Th2/Thl7 cells could play a decisive role in sever asthma and process of mutual transformation between different asthma phenotypes. The aim of this review is to propose how Th2/Th17 ceils function in asthma.