CD4^+细胞根据释放细胞因子不同可分为不同的亚型:辅助性T细胞(T helper cells,Th)1、Th2和调节性T细胞(regulatory T cells,Treg)。最近发现了一种新的CD4^+T细胞亚型:以分泌白细胞介素-17为主要特征的Th17细胞。Th17细胞的发现对CD4^+T细胞分化、Th细胞漂移等传统理论提出了挑战,同样也为感染、免疫性疾病提供了新的研究思路,尤其是Treg、Th1、Th2和Th17细胞在体内的平衡对于维持正常免疫应答反应有重要意义。
CD4^+ T cells have been divided into different subsets, essentially based on the cytokines they produce. These subsets include T helper cell (Th)1, Th2 and regulatory T cells (Treg). Recently, another subpopulation of T cells has been identified, and it was named as Thl7, which is characterized by the release of interleukin (IL)-17. The discovery of Th17 cells is not only a challenge to some traditional theories, such as the differentiation of CD4^+ T cells and the drift theory of Th1/Th2, but also provides new research approach to inflammatory and immunologic diseases, especially, the balance among Thl, Th2, Treg and Th17 cells may play an important role in maintaining the normal immune response.