细胞凋亡诱导大鼠肝移植免疫耐受的实验研究

Study on apoptosis induced immune tolerance in rat model of liver transplantation

目的:探讨细胞凋亡诱导移植受体存活的影响,并分析骨髓细胞输注诱导移植肝早期存活的机制。方法:Kamada法建立大鼠肝移植模型,随机法分4组(n=8)。A组:同品系移植组;B组:免疫排斥组;C组:B组+免疫抑制剂;D组:C组+骨髓细胞输注。流式细胞和TUNEL法检测外周血和移植物细胞凋亡。结果:术后第6天移植肝和外周血中凋亡细胞存在,D组中细胞凋亡发生率明显高于B组和C组,凋亡细胞为浸润细胞和肝实质性细胞;D组浸润淋巴细胞为主。细胞凋亡和移植肝组织中TGF-β1mRNA表达相关。结论:移植物中早期的细胞凋亡可能和移植免疫耐受诱导有关,供体骨髓细胞输注在一定程度上是通过细胞凋亡的发生来诱导移植物的早期存活。

Objective To investigate the effect of apoptosis on the survival of the induced recipient after liver transplantation in rats, and to analyze the mechanism of the long survival of liver grafts after transfusion with donor bone marrow. Methods According to Kamada two-cuff methods, we established the animal model of liver transplantation. They were divided into four groups. Group A： the homologous rats; group B： the nonhomologous ones; group C： based on the group B, FK506 and MMF were used for two days after operation, and then FK506 alone used for another two days; group D： based on the group C, donor bone marrow was transfused by caudal vein. The TUNEL assay and flow cytometry were performed for the detection of apoptotic ceils. Results The apoptosis cells existed in both liver grafts and peripheral bloods in all groups. The counting of apoptosis cells was significantly more in the group D than in either group B or C. The apoptosis cells were the infiltrating cells and liver parenchymal cells. The infiltrating cells were the main apoptotic cells in group D. The number of apoptotic cells correlated with the expression of TGF-[31 mRNA. Conclusions The detection of apoptotic cells in the liver grafts and serum indicated that early cell death was associated with tolerance rather than rejection. The transfusion of donor bone marrow may increase incidence of apoptosis, which may be one possible mechanism of allografts tolerance.