调节性CD4+T细胞在大鼠自发肝移植耐受中的作用

目的 探讨在肝移植的自发耐受模型中，调节性CD4^＋T细胞的免疫抑制作用机制。方法 利用近交系大鼠从Lewis（LEW）到Wistar Furth（WF）的肝移植组合，对移植后不同时期的宿主注射抗CD4的单克隆抗体（Anti-CD4mAb），然后抽血检测丙氨酸氨基转氨酶（ALT）的动态变化；并结合细胞毒性T淋巴细胞（CTL）试验了解宿主脾细胞中T细胞亚群的动态改变。结果 对肝移植自然生存的宿主注射Afiti—CD4mAb后，术后第21天、42天均能够诱导出肝损害（排斥反应），但第56天、100天以上的则未能诱导出来，且该损害能被抗CD8单克隆抗体阻断。另外CTL试验显示宿主的脾细胞中，初始型CTL前体细胞在移植56d后未能检测出来。结论 在自发性肝耐受模型中。宿主术后早期存在由CD4^＋T细胞介导的下调原始效应性T细胞的作用机制。

Effect of regulative CD4 T -cell on spontaneous immune tolerance of liver transplantation in rats

Objective To explore the effect of regulative CD4+T cell in spontaneous immune tolerance of liver transplantation in rat model.Methods Monoclonal anti-CD4 antibody (anti-CD4 Ab) was injected into recipients at different stage after liver transplantation from Lewis (LEW) to Wistar Furth (WF) rats.Serum ALT was determined at each stage.Successive changes of subgroups of T cells in spleen cells were studied by cell toxic lymphocyte (CTL) test.Results The liver injury was induced at the 21st,42nd post-operative day for the recipients after administration of anti-CD4 mAb,however,it failed at the 56th and over the 100th post-operative day,and the injury could be interdicted by monoclonal anti-CD8 antibody.In addition,CTL test showed that primary CTL cells could not be detected at the 56th post-operative day in the spleen cells from recipients.Conclusion There exists pathway of primary effective T cells down-regulated by CD4+T cell at early stage postoperation in recipients in the model of spontaneous tolerance of liver transplantation.