移植心Th细胞免疫偏离与MHCⅡ类抗原表达的关系

Relationship between helper Tlymphocytes immune deviation and classⅡMHC antigen expression in acute rejection of transplanted heart

目的 :探讨Th细胞免疫偏离与移植心MHCⅡ类抗原表达的关系。方法 :建立大鼠心脏移植模型 ,以同系移植和无移植动物作为对照 ,采用逆转录PCR技术测定移植心Ⅰ、Ⅱ类细胞因子IL - 2、IL - 4mRNA水平变化 ,用免疫组化技术和单克隆抗体测定移植心MHCⅡ类抗原表达。结果 :IL - 2mRNA水平和MHCⅡ类抗原表达随着移植心急性免疫排斥病变发展而显著增加 (P <0 0 1) ,IL - 4mRNA水平则显著降低 (P <0 0 1) ,急性免疫排斥发展到一定阶段Ⅰ、Ⅱ类细胞因子水平出现偏离时MHCⅡ类抗原由低表达变为高表达。结论 :移植心脏急性免疫排斥过程中 ,Th细胞免疫偏离与MHCⅡ类抗原表达变化有相关性 。

AIM: To observe the relationship between the immune deviation of Th1 and Th2 cell clones and class Ⅱ major histocompatibility complex (MHC) antigen expression in different stages of acute rejection in transplanted hearts. METHODS: Heart transplantation were performed in rats.Isografts and non-transplanted animals were used as control group. Donor class II MHC antigen expression were detected with monoclonal antibodies and immunostaining technique and the amount of type Ⅰ and Ⅱ cytokines mRNA expression were detected by semiquantitative RT-PCR in cardiac allografts. RESULTS: Myocardial IL-2 mRNA and donor class Ⅱ MHC antigen expression were significantly in creased, accompanied with development of acute rejection( P<0.01 ). However, IL-4 mRNA decreased significantly ( P<0.01 ). The immune deviation between type Ⅰ and Ⅱ cytokines mRNA expression occurred in the rejecting stage at which the cardiac allograft tissue infiltrated by multiple foci of lymphocytes and class Ⅱ MHC antigen became highly expressed.CONCLUSIONS: There was correlationship between Th cells immune deviation and donor class Ⅱ MHC antigen expression in the process of acute rejection in cardiac allografts. Immune deviation of T cells may facilitated the expression of donor MHC class Ⅱ antigen on transplanted heart.