CTLA4-Ig诱导大鼠同种肝细胞移植免疫耐受的实验研究

Rat allogeneic hepatocyte transplantation immune tolerance induced by CTLA4-Ig

目的研究CTLA4-Ig诱导在D-氨基半乳糖致急性肝功能衰竭大鼠脾内同种异体肝细胞移植的免疫耐受。方法急性药物性肝衰模型:用10%D-氨基半乳糖溶液按1.0 g/kg一次性大鼠腹腔注射;用Ⅳ型胶原酶肝脏原位灌注,制备肝细胞悬液,浓度为4×107/ml,2 h内经脾移植;24只用D-氨基半乳糖诱导的急性肝衰大鼠,24 h后均进行经脾同种异体肝细胞移植,然后随机分为两组,一组为治疗组,腹腔一次性注射CTLA4-Ig,另一组为对照组,不予处理。两组均分别于术后第1,3,5,7天观察IL-2、TNF、肝功能及脾脏HE染色的变化。结果治疗组与对照组比较,术后治疗组IL-2含量明显下降,差异有显著性,P<0.05;术后TNF含量两组之间差异无显著性,P>0.05;术后肝功能治疗组比对照组下降明显,P<0.05。组织学改变:术后第7天治疗组仍可见肝细胞或肝细胞团,对照组脾内见大量淋巴细胞浸润,但很少见肝细胞。结论CTLA4-Ig能诱导大鼠经脾同种异体肝细胞移植的免疫耐受,促使急性肝衰大鼠肝功能得到改善。

Objective To study immune tolerance induced by CTLA4-Ig after intrasplenic hepatocyte transplantation for treatment of D- galactoeamine-induced acute liver failure in rats. Methods The model of acute chemical liver failure： 10 % D-galactosarnine 1.0 g/ kg was injected into abdominal cavity of SD rats. Livers were perfused with collagenase type IV. The concentration of hepatocytes was 4 - 107/ml. Some of hepatocytes were transplanted through spleens within 2 h. At 24 h after injection with D-galactosamine,24 rats received allogeneic hepatocytes through spleens, and were randomly divided into two groups. One group received CTLA4-Ig by intraperitoneal injection. The concentration of IL-2 and TNF, liver function and histology were observed on d 1,3,5 and 7 after operation. Results IL-2 of the experimental group was significantly decreased after operation （ P 〈0.05）. TNF had no difference betwcen two groups after operation（P 〉0.05）. The liver function of experimental group （ALT,TBIL） was significantly reduced （P〈 0.05）. Histological changes： on 7 d after operation, there were some hepatocytes in the experimental group＇ s spleens. But in control group＇s spleens, the changes were characterized by severe lymphocyte infiltration, and there were no hepatocytes in spleens. Conclusion CTLA4-Ig can induce rat allogeneic hepatocyte intrasplenic transplantation immune tolerance, and improve the liver function of acute liver failure rats.