大鼠肝移植排斥反应时γ干扰素及白细胞介素10的表达及意义

Expression and significance of IFN-γ and IL-10 in the process of graft rejection following liver transplantation in rats

目的探讨大鼠肝移植排斥反应时γ干扰素（IFN-γ）及白细胞介素10（IL-10）的表达及意义。方法采用改良的Kamada“二袖套法”制备大鼠原位肝移植模型，同系移植组供、受者均为SD大鼠；同种异体移植组的供者为Wistar大鼠，受者为SD大鼠；另设假手术组。术后7d处死动物，观察移植肝脏的组织学变化，检测血清IFN-γ和IL-10的含量，以及移植肝脏内IFN-γ和IL-10mRNA的表达。结果同种异体移植组移植肝脏有较多坏死肝细胞，汇管区及中央静脉周围可见以淋巴细胞为主的炎症细胞浸润，胆管上皮细胞可见胞浆空泡变性、核固缩或碎裂，整个肝小叶结构紊乱。同系移植组肝脏组织结构仅有轻度缺血再灌注损伤表现，汇管区有较少炎症细胞浸润，胆管上皮细胞结构和肝小叶结构基本正常。同种异体移植组血清IFN-γ为（386．7±14．4）pg／ml，明显高于同系移植组的（159．8±16．5）pg／ml（P〈0．05）；同种异体移植组血清ILl0为（126．3±13．1）pg／ml，明显低于同系移植组的（288．3±17．1）pg／ml（P〈0．05）。同种异体移植组移植肝组织内IFN-γ mRNA表达水平明显高于同系移植组（P〈0．05），而IL-10 mRNA表达水平明显低于同系移植组（P〈0.05）。结论大鼠肝移植排斥反应时IFN-γ表达明显升高，IL-10表达明显降低；TH1／TH2型细胞因子的动态平衡可能在大鼠肝移植排斥反应中起着重要作用。

Objective To explore the expression of IFN-γ and IL-10 in lymphocytes in the process of the graft rejection process following liver transplantation in rats and their biological significances. Methods Orthotopic liver transplantation （OLT） models were established by modified Kamada two-cuff technique. Recipients were divided into three groups. The allograft group underwent OLT from male Wistar-to-Sprague-Dawley （SD） rats. The isograft group of SD-to-SD liver transplantation was complemented with a control group of normal male SD rats that had sham operations. The histological changes were examined, as well as serum and mRNA expression levels of IFN-γ and IL-10. Results Serious morphological changes were observed in the allografted hepatic tissue. Many necrotic hepatocytes were seen and vacuolar degeneration of kytoplasm, karyopycnosis even nuclear fragmentation was observed in biliary duct endothelial cells. Many inflammatory cells infiltrated the portal areas, and the architecture of the liver lobules was destroyed. In contrast there were mild morphological changes in isograft hepatic tissue. A few inflammatory cells infiltrated the portal area; the hepatic lobule structure remained and biliary duct endothelial cells were nearly normal. Serum IFN-γ levels （pg/ml） determined by ELISA in the allograft group and isograft group were 386. 7 ±14. 4 and 159. 8±16. 5 respectively （P〈0. 05） ; for IL-10, they were 126. 3±13. 1 and 288. 3±17. 1, respectively （P〈0. 05）. The semiquantitative reverse-transcriptase polymerase chain reaction assay showed that expression levels of IFN-γ and IL-10 mRNA were similar to those in serum. Conclusion The expression of IFN-γ was obviously advanced in graft rejection following liver transplantation in rats and the expression of IL-10 was depressed. The dynamic equilibrium of TH1/TH2 cytokines is very important in the process of graft rejection following liver transplantation in rats.