免疫平衡的重要调节者白细胞介素-21

白细胞介素-21（IL-21）是γc家族的一个新成员,主要由活化的CD4＋ T细胞产生,对多种表达IL-21受体（IL-21R）的细胞如T细胞、B细胞、NK细胞及DC细胞等均有作用。近年发现IL-21与Th细胞系中新发现的分支Th17细胞的发生密切相关,在调节CD4＋ T细胞究竟是分化为Th17细胞还是CD4＋CD25＋Foxp3＋ Treg细胞中有＂开关＂作用,从而对免疫系统发挥重要的调节作用,在自身免疫性疾病和抗肿瘤免疫中扮演着重要的角色。简要综述了IL-21与Th17细胞、CD4＋CD25＋Foxp3＋ Treg细胞之间的关系及对免疫平衡的调节作用。

Interleukin 21:an Important Modulator of Immune Balance

Interleukin 21（IL-21）, which is produced by activated CD4＋ T cells, is the latest member of γc family, and showing function on the different cells expressing IL-21 receptor （IL-21R）, such as T cells, B cells, NK cells and DC. Recently, it was found that IL-21 was closely associated with a new Th cells lineage, Th17, and has a switch function on inducing CD4＋T cells differentiation to Th17 cells or CD4＋CD25＋Foxp3＋ Treg cells. So IL-21 maybe an important modulator of immune system, and has a role in autoimmunity and anti-tumor immunity. This review mainly focused on the relationship of Th17 cells with CD4＋CD25＋Foxp3＋ Treg cells and the role in immune balance.