白介素13受体及其亚型研究新进展

白介素13(interleukin-13,IL-13)是主要由活化的Th2细胞分泌的免疫调节因子,在过敏性炎症反应过程中起着重要的作用.其各种功能通过复杂的受体系统来完成,包括IL-4受体αa(IL-4Rα,CD124)和其他同族的两个细胞表面蛋白:IL-13受体al(IL-13Rα1,CD231α1)和IL-13受体α2(IL-13Rα2,CD231α2).在IL-13R中IL-13Rα1和IL-4Rα以同源二聚体形式存在.相反IL-13Rα2由于它的较短的胞内蛋白形式被认为是一个诱导受体.IL-13Rα2以胞膜蛋白、胞内蛋白和胞外可溶性蛋白3种形式存在.近来报道显示,膜性IL-13Rα2可能有信号转导的功能,可溶性IL-13Rα2可调节IL-13反应.可溶性受体IL-13Rα2比诱导受体有着更加复杂的功能.在这里我们将详述IL-13R的亚型并讨论IL-13Rα2功能.

Interleukin-13 receptor isoforms: breaking through the complexity

Interleukin(IL)-13 is an immunoregulatory cytokine secreted predominantly by activated T-helper type 2(Th2)cells,and it has been identified as crucial factor in developing allergic inflammatory respnses.Its diverse functions are mediated by a complex receptor system including IL-4 receptor α(IL-4Rα; CD124)and two other cognate cell surface proteins,IL-13Rα1(CD231α1)and IL-13Rα2(CD231α2).IL-13Rα1 forms a heterodimer with IL-4Rα that is a signaling IL-13R.In contrast,IL-13Rα2 has been thought to be a decoy receptor due to its short cytoplasmic tail.IL-13Rα2 exists on the cell membrane,intracellularly,and in soluble form.Recent reports revealed that membrane IL-13Ra2 may have some signaling capabilities,and soluble IL-13Ra2 is a critical endogenous modulator for IL-13 responses.The receptor has more complicated functions than a simple decoy receptor.This review describes the isoforms of IL-13Rα2 and discusses newly revealed functions of IL-13Rα2.