T细胞免疫球蛋白粘蛋白分子-4在免疫应答中作用及其与免疫疾病的关系

Role of T-cell immunoglobulin and mucin-domain-containing molecule-4 in immune response and its relationship with immunological diseases

T细胞免疫球蛋白粘蛋白分子(T-cell immunoglobulin and mucin-domain-containing molecule,TIM)基因是近年发现的新的基因家族。TIM家族蛋白在调节免疫应答中发挥重要作用。TIM-4是TIM家族一个成员,是一种I型跨膜糖蛋白分子。TIM-4仅表达在活化的树突状细胞(dendritic cell,DC)和巨噬细胞的表面,它是TIM-1的体内天然配体。TIM-1与TIM-4相互作用可调节T细胞活化增殖,调节Th1/Th2细胞平衡。此外,TIM-4可与磷脂酰丝氨酸结合,促进巨噬细胞对凋亡细胞的吞噬作用。因而,TIM-4与一些过敏疾病和自身免疫疾病存在相关性。

The TIM（T-cell immunoglobulin and mucin-domain-containing molecule） gene family was discovered nine years ago.It has been shown to play an important role in T cell responses.TIM-4,one member of the protein family,is a type I transmembrane glycoprotein only expressed on mature lymphoid dendritic cells and macrophages.TIM-4 is a natural ligand for TIM-1 and the TIM-4/TIM-1 interaction regulates T cell proliferation.It also regulates the balance of Th1/Th2 cells.Recent study reveals that TIM-4 is also a receptor of phosphatidylserine（PtdSer）.When binding to PtdSer,TIM-4 is critical for the efficient clearance of apoptotic cells and regulation of autoimmune diseases.In short,TIM-4 is associated with some allergic diseases,as well as autoimmune diseases.