大鼠同种肝移植免疫耐受机制的研究

目的:探讨与大鼠肝移植免疫耐受相关的细胞学改变。方法:分析从肝移植物分离出的移植物浸润细胞(GIC)的表现型和功能,同时比较长期生存的BN→LEW模型和急性排斥反应的DA→LEW模型。结果:通过流式细胞仪计数确定DA→LEW受体的T细胞和激活的T细胞相对比例高于BN→LEW受体;移植后第7、14和30天,GIC表现型证实所有T细胞、OX8阳性细胞(细胞毒T细胞和NK细胞)和OX39阳性细胞(IL-2受体)的相对比例在移植后第7天最高,移植后30d下降;移植后第7天急性排斥反应时GIC细胞毒T细胞活性高于长期生存者。结论:移植后第7天免疫抑制机制已存在;在长期生存的肝移植物中细胞毒T细胞的激活和浸润均受到抑制。

Experimental study on the immunological tolerance in rat liver transplantation

Objective To elucidate the immunological characteristics of rat liver transplantation. Methods The graft1,infiltrating cells (GIC) isolated from rat hepatic allografts were analyzed phenotypically and functionally. GIC from long1,surviving recipients (Brown Norway livers into Lewis hosts) were compared with the acutely rejecting recipients (DA livers into Lewis hosts). Results The relative proportions of all the T cells and the activated T cells determined by flow cytometry were significantly higher in the acutely rejecting Lewis recipients than in the long1,surviving recipients on day 7 after grafting. The phenotypic analysis of GIC on day 7, 14 and 30 after transplantation from long1,surviving Lewis hosts showed that each proportion of all the T cells, the OX81,positive cells (cytotoxic T and natural killer cells) and the OX391,positive cells (IL1,2 receptor) was the greatest on day 7 and decreased on day 30. The cytotoxic activity of GIC toward donor lymphocytes on day 7 was greater in the acutely rejecting than that in the long1,surviving recipients. Conclusions The immunosuppressive mechanism is already present on day 7 posttransplantation, and the infiltration or activation of the cytotoxic T cells is inhibited in the long1,surviving rat hepatic allografts.