Fas配体表达诱导同种胰岛移植免疫豁免

目的　探究睾丸细胞FasL表达能否对同时移植的胰岛移植物提供免疫豁免作用。方法　将不同数量的同种大鼠睾丸细胞与1500个胰岛同时移植于糖尿病受体，观察移植物功能、存活情况，以及移植物内淋巴细胞凋亡情况，并体外检测睾丸Sertoli细胞对活化淋巴细胞的抑制作用。结果　单纯移植胰岛组平均存活期为(5.0±0.5)d。睾丸细胞和胰岛细胞同时移植，当睾丸细胞数为5×106个，平均存活期为(10.0±0.6)d；增加移植睾丸细胞数至1×107个时，存活期大于50d（P＜0.05）。表达FasL的睾丸细胞在移植物内诱导浸润淋巴细胞凋亡，体外抑制淋巴细胞活性。结论　表达FasL的睾丸细胞可诱导浸润的活化淋巴细胞凋亡，使同时移植胰岛移植物获得局部免疫豁免、存活期延长。

Fas ligand expression induced immune privilege of pancreatic islet allografts

Objective　To investigate the immune privilege of islet allografts induced by the Fas ligand (FasL) expressed by cotransplanted testicular Sertoli cells.　Methods　Different testicular cells and 1 500 allogeneic islets were cotransplanted respectively in diabetic recipients. Allografts survival, the apoptosis of infiltrative lymphocytes in allografts，the islets function and the cytotoxicity of Sertoli cells to the activated lymphocytes in vitro were analyzed.　Results　All animals receiving islet allograft alone returned to a diabetic state by several days ［mean survival time (5.0±0.5) days］. When islets were cotransplanted with 5×106 testicular cells, the mean survival time of allografts was (10.0±0.6) days. When the quantity of testicular cells was increased to 1×107, all of the animals remained normoglycemic throughout the follow-up period (P<0.05). The FasL expression by cotransplanted Sertoli cells induced apoptosis of the activated lymphocytes.　Conclusion　FasL-expressing testicular Sertoli cells can induce apoptosis of infiltrative lymphocytes and allows long-term survival of allogeneic islets because of immune privilege.