转FasL基因的树突状细胞诱导大鼠肝移植免疫耐受的实验研究

An experimental study on inducement of rat liver transplantation tolerance by constructing retroviral vector containing FasL gene

目的 观察转FasL基因的树突状细胞 (DC)体内注射诱导大鼠肝移植免疫耐受作用 ,并研究其机制。方法 用“二袖套法”行受体为Wistar大鼠肝移植 36例 ,并随机分为 3组 :①对照组(n =12 ) ;②环孢霉素治疗组 (n =12 ) ;③转FasL基因治疗组 (n =12 ) ,腹腔注射转FasL基因的树突状细胞。手术后 7d分别杀死各组 4只大鼠 ,用原位末端标记法及透射电镜观察移植肝细胞及肝脏内淋巴细胞凋亡 ,其余大鼠用于观察生存期。结果 对照组大鼠在 9～ 15d迅速死亡 ,TUNEL及电镜观察发现肝细胞变性坏死明显 ;而环孢霉素治疗组及转FasL基因治疗组免疫排斥反应轻微 ,移植后大鼠已存活超过 6个月 ,原位末端标记法及透射电镜均发现FasL基因治疗组肝脏内浸润淋巴细胞凋亡明显。结论 转FasL基因DC细胞治疗能有效地诱导肝移植免疫耐受 。

Liver Transplantation Center, the First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, P. R. China Objective To explore the immune tolerance induced by in vivo injection of dendritic cells from the donor transfected with FasL gene and investigate the possible mechanism of immune tolerance inducement. Methods Orthotopic transplantation in 36 Wistar rats receiving SD liver was performed using 'the two cuff technique' with some modifications. Then the rats were randomized into 3 groups: (1) the control group (n=12);(2) CsA group (n=12);(3) FasL group (n=12). The rats in CsA group were treated with cyclosporine while those in FasL group with the dendritic cells transfected with FasL gene by intraperitoneal injection. Four rats in each were killed on the 7 postoperative day. The apoptosis of lymphocytes in liver was evaluated by TUNEL and the ultrastructure of the graft observed with electron microscopy. Meanwhile, postoperative survival time of the rats in each group was recorded. Results All the rats in the control group died between 9 15 days after the operation. There were hepatocytes with degeneration and necrosis. The immune rejection in CsA group and FasL group were slight and the survival time had surpassed 6 months. There were lymphocyte apoptosis in liver tissue in FasL group. Conclusions The therapy of DC transfected with FasL gene can induce immune tolerance of liver transplantation. The mechanism of which might be inducing apoptosis of activated lymphocytes.