近交系大鼠肝移植自发免疫耐受模型的建立及其CD8+CD28-T细胞的作用

目的建立近交系大鼠原位肝移植自发免疫耐受模型,并研究CD8+CD28- T细胞在自发免疫耐受形成中的作用.方法双袖套法建立原位肝移植模型;流式细胞技术检测CD8+CD28- T抑制细胞含量变化;利用补体细胞毒和免疫磁珠方法分离CD8+CD28- T细胞,通过体外混合淋巴细胞反应验证其抑制功能.结果我们成功建立了BN(供体)LEW(受体)原位肝移植自发免疫耐受模型,并发现自发免疫耐受模型大鼠脾脏CD8+CD28- T细胞含量(23.7%±7.2%)显著高于正常大鼠(5.4%±1.5%)和急性排斥组大鼠(6.0%±1.3%),而且,分离纯化后的自发免疫耐受组大鼠脾脏CD8+CD28- T细胞可以抑制混合淋巴细胞反应的增殖,但急性排斥组大鼠脾脏CD8+CD28- T细胞无抑制功能.结论 BN(供体)LEW(受体)原位肝移植模型为自发免疫耐受;脾脏CD8+CD28- T细胞作为一种T抑制细胞,在自发免疫耐受的形成过程中具有重要作用.

Establishment of orthotopic liver transplantation model of inbred rats with spontaneous tolerance and study on role of CD8+CD28- T cells

Objective To establish the orthotopic liver transplantation(OLT) model of inbred rats and explore the role of spleen CD8~+CD28~T cells in spontaneous tolerance of the model.Methods The OLT model of inbred rats was established according to double-sheeve technique.The proportional changes of spleen CD8~+CD28~-T cells were determined by flow cytometry.Spleen CD8~+CD28~-T cells were sorted by complement-dependent cytotoxicity and immunomagnetic beads.The suppressing activity of the spleen CD8~+CD28~-T cells was tested by mixed lymphocyte reaction in vitro.Results An OLT model of spontaneous tolerance was established between BN(donor) and LEW(recipient) inbred rats.After OLT,spleen CD8~+CD28~-T cells in the spontaneous tolerance model were elevated to 23.7% 7.2%,which was more than that in the normal control(5.4% 1.5%) and acute rejection model 6.0% 1.3%).The spleen CD8~+CD28~-T cells isolated from the spontaneous tolerance model but not acute rejection model could inhibit the proliferation of mixed lymphocyte reaction.Conclusions The spleen CD8~+CD28~-T cells isolated from the spontaneous tolerance model are an unique kind of suppressor T cells.Meanwhile,they might play an important role in induction of spontaneous tolerance.