Fas/FasL系统及其在葡萄膜炎中的意义

The role of Fas/FasL in uveitis

Fas是一种具有重要功能的跨膜糖蛋白 ,为肿瘤坏死因子受体超家族的成员之一 ,其自然配体为FasL(FasLigand)。Fas与FasL或Fas单克隆抗体结合可诱导Fas+ 细胞的凋亡。Fas系统诱导的细胞凋亡可消除自身反应性淋巴细胞 ,诱导活化T、B细胞凋亡 ,参与免疫赦免形成 ,从而维持机体生理平衡和自身免疫耐受。Fas/FasL系统的异常在自身免疫性葡萄膜炎发生中可能起着一定的作用 ,自身免疫性淋巴细胞对Fas/FasL系统诱导的凋亡有较大抵抗性 。

Fas antigen is a cell surface protein belonging to nerve growth factor/tumor necrosis factor receptor family.Fas ligand is a type Ⅱ trandmembrane protein belonging to tumor necrosis factor family.Both Fas and FasL are important molecules involved in the control of cell death.Fas and FasL intereaction produces signals leading to apoptosis of target cells.Apoptosis induced by Fas/FasL system may have several functions.It can assure self tolerance,control antoreactive lymphocytes cell and maintain immune privilege.The autoimmune mechanisms are involved in uveitis.Uveitis,like other autoimmune diseases, run a long and recurrent course.Malfunction of the Fas/FasL system or other functional disturbances in apoptosis may be responsible for the perpetuation and recurrence of uveitis.