The Third Hospital Affiliated to Nantong University, Wuxi, 214041 Jiangsu, People's Republic of China.
Mol Biol Rep. 2011 Mar;38(3):1717-21. doi: 10.1007/s11033-010-0285-x. Epub 2010 Sep 17.
Interleukin-21 (IL-21) is a new member of the type I cytokine superfamily, which binds to a composite receptor that consists of a private receptor (IL-21R) and the common cytokine receptor γ chain. Recently, increasing evidence has shown that IL-21 contributes to the pathogenesis of chronic inflammatory and autoimmune diseases because of its pro-inflammatory and immune-mediated properties. IL-21 induced T-cell activation and pro-inflammatory cytokine secretion in rheumatoid arthritis (RA). IL-21R RNA transcripts were found in synovial tissue samples of patients with RA. In addition, blockade of the IL-21/IL-21R pathway ameliorated disease in animal models of RA and significantly inhibited inflammatory cytokine production in vitro. Moreover, IL-21R deficiency in the K/BxN mouse model of inflammatory arthritis was sufficient to block arthritis initiation completely. All theses findings suggest that IL-21 has important biological effects in autoimmunity that might be a promising therapeutic target for RA. In this review, we discuss the biological features of IL-21 and summarize recent advances in the role of IL-21 in the pathogenesis and treatment of RA.
白细胞介素 21（IL-21）是细胞因子超家族 I 的一个新成员，它与由一个独特受体（IL-21R）和常见细胞因子受体γ链组成的复合受体结合。最近，越来越多的证据表明，由于其促炎和免疫介导的特性，IL-21有助于慢性炎症和自身免疫性疾病的发病机制。IL-21 诱导类风湿关节炎（RA）中的 T 细胞活化和促炎细胞因子分泌。在 RA 患者的滑膜组织样本中发现了 IL-21R RNA 转录本。此外，阻断 IL-21/IL-21R 途径可改善 RA 的动物模型中的疾病，并显著抑制体外炎症细胞因子的产生。此外，在炎症性关节炎的 K/BxN 小鼠模型中缺乏 IL-21R 足以完全阻断关节炎的发生。所有这些发现表明，IL-21 在自身免疫中具有重要的生物学效应，可能成为 RA 的有希望的治疗靶点。在这篇综述中，我们讨论了 IL-21 的生物学特征，并总结了最近在 IL-21 在 RA 的发病机制和治疗中的作用方面的进展。
