小肠移植排斥反应期移植肠基因表达的研究

Intragraft mRNA expression in small intestinals intestinal rejection

目的了解大鼠小肠移植排斥反应期移植肠粘膜白细胞介素2（IL-2）、γ干扰素（IFN-γ）、穿孔素、粒细胞酶B的mRNA表达的变化。方法选用近交系大鼠F344／N和Wistar/A进行全小肠异位移植，实验分4组，第1组：非手术对照组;第2组：同基因移植对照组;第3组：异基因移植组;第4组：环抱菌素A治疗组（6mg·kg-1.d-1）。术后第3、5、7天取各组动物移植肠标本进行病理学检查，检测移植肠IL-2、IFN-γ、穿孔素、粒细胞酶B的mRNA表达。结果（1）病理学检查显示第3组大鼠在术后第3、5、7天分别符合轻、中、重度排斥。第2、4组无明显排斥征象;（2）第1组各检测基因基本不表达。第3组IL02mRNA表达在术后第5天明显高于第2组（P＜0.05）;IFN-γmRNA表达术后始终明显高于第2、4组（P＜0.01）;穿孔素、粒细胞酶BmRNA表达在术后第5、7天均高于第2、4组，且差异有显著意义。结论IL-2、IFN-γ、穿孔素和粒细胞酶B的转录在小肠移植排斥中发挥了重要作用;IL-2mRNA、IFN-γ、穿孔素、粒细胞酶BmRNA表达检测，可能为临床小肠移植排斥反应的早期诊断提供特异、敏感的方法;通过阻断IL-2、IFN-γ、穿孔素、粒细胞酶B的转录可能能达到小肠移植抗排斥或诱导免疫耐受的目的。

Objective To investigate the changes of intragraft mRNA expression of IL-2, IFN-γ,perform, glanzyme B during small intestinal allograft rejection in rats. Methods Heterotopic small intestinal transplantation was performed with inbred rat F344/N(RT11) and inbred rat Wistar/A(RT1-Ak, RT1-Ed). All recipients were divided into four groups; group Ⅰ, Wistar;group Ⅱ, Wistar→Wistar;group Ⅲ, F344→Wistar;and groupⅣ, F344→Wistar+ cyclosporine A(6mg/kg d-1). The grafts were harnested on POD 3, 5 and 7, All graft samples were examined histologically The intragraft mRNA expression of IL-2, IFN-γ, perform and granzyme B was determined. Results ①The histological examination showed thai mild acute rejection occurred on POD 3 in group Ⅲ, moderate acute ejection on POD 5, severe acute rejection on POD 7, while none of group Ⅱ had histologic evidence of acute rejection. The histologic evidence of group Ⅳ indicated that cyclosporine A could effectively controll acute allograft rejection. ② The gene expression was almost negative in group 1. Only on POD 5 was the IL-2 mRNA expression of group Ⅲ significantly higher than that of group Ⅱ (P＜ 0.05). The IFN-γ mRNA expression of group Ⅲ was significantly higher than that of group Ⅱ and group Ⅳ (P＜0.01) on POD 3,5 and7. The level of perform and granzyme B mRNA expression was significant higher in group Ⅲ than in the other two control groups only on POD 5 and ac 7. Conclusions IL-2, IFN-γ, perform and granzyme B play important roles in small intestinal allograft dejection. Detection of these molecules gene expression with RT-PCR,espeially the gene expression of IFN-γ, perform and granzyme can become an early, specific, sensitive and clinically valuable diagnostic tool for small intestinal allograft rejection. Furthermore, anti-rejection therapy or induction of immune tolerance could be wheyed by breaking down these molectules gene transcription.