细胞毒T淋巴细胞在异种肝移植急性排斥反应中的作用

Effect of cytotoxicity T lymphocyte on acute rejection of xenogenic liver transplantation

目的 探讨异种肝移植中细胞毒T淋巴细胞 (CTL)参与急性排斥反应的机制。 方法 三袖套法建立仓鼠到大鼠原位肝移植模型 ;免疫组化方法检测同基因组与异种移植组 (XT组 )移植肝术后CD8和CD4型淋巴细胞浸润及Fas L ,穿孔素的表达情况 ,并运用原位末端标记法检测移植肝细胞的凋亡情况。 结果 XT组移植肝术后第 2d汇管区出现淋巴细胞浸润 ,逐日增多 ,至术后 5～ 6d达高峰 ;术后第4d穿孔素及Fas L开始表达 ,术后第 5～ 6d达高峰 ;穿孔素的表达始终高于Fas L。 结论 异种肝移植中T淋巴细胞参与了其免疫排斥反应 ,通过表达穿孔素或Fas L使靶细胞坏死或凋亡。

Objective To study the mechanism of cytotoxic T lympocytes in the acute rejection of xenogenic liver transplantation(XLT). Methods Hamster to rat orthotopic liver transplantation model was performed with three cuff method. In XLT,lymphocytes including CD8 and CD4 subsets were observed by histology and immunohistochemistry; the expression of perforin and Fas- L was observed by immunohistochemistry; and apoptotic cells of XLT were observed in situ end-labelling of fragmented DNA. Results In the XLT, T cell infiltration firstly ocurred on the 2nd day posttansplantation and located at the portal triads; the infiltrating lymphocytes proliferated increased with time and reached the peak on the 5th to 6th days.Perforin and Fas-ligand were expressed on the 4th day after XLT, and peaked on the 5th to 6th day,and the expression of perforing was still higher than the expression of Fas-ligand. Conclusions T lymphocyte participates in the acute rejection of XLT through the expression of perforin and Fas-ligand, which leads to apoptosis or necrosis of hepatocytes.