Mehta Devangi S, Wurster Andrea L, Grusby Michael J
Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115, USA.
Immunol Rev. 2004 Dec;202:84-95. doi: 10.1111/j.0105-2896.2004.00201.x.
Interleukin-21 (IL-21) is the newest member of the common gamma-chain family of cytokines, which includes IL-2, IL-4, IL-7, IL-9, IL-13, and IL-15. Its private receptor, IL-21R, has been shown to activate the Janus kinase/signal transducers and activators of transcription signaling pathway upon ligand binding. Initial studies have demonstrated that IL-21 has pleiotropic effects on the proliferation, differentiation, and effector functions of B, T, natural killer, and dendritic cells. More recently, the potential therapeutic capacity of IL-21 in the treatment of cancers has been widely investigated. The biological role of IL-21 in the immune system is complex, as IL-21 has been shown to have the ability to both promote and inhibit immune responses. Overall, the current data point to IL-21 being a novel immunomodulatory cytokine, whose regulation of any given immune response is highly dependent on the surrounding environmental context.
白细胞介素-21（IL-21）是细胞因子共同γ链家族的最新成员，该家族包括IL-2、IL-4、IL-7、IL-9、IL-13和IL-15。其特异性受体IL-21R已被证明在配体结合后可激活Janus激酶/信号转导子和转录激活因子信号通路。初步研究表明，IL-21对B细胞、T细胞、自然杀伤细胞和树突状细胞的增殖、分化及效应功能具有多效性作用。最近，IL-21在癌症治疗中的潜在治疗能力已得到广泛研究。IL-21在免疫系统中的生物学作用很复杂，因为IL-21已被证明既有促进免疫反应的能力，也有抑制免疫反应的能力。总体而言，目前的数据表明IL-21是一种新型免疫调节细胞因子，其对任何特定免疫反应的调节高度依赖于周围的环境背景。
