摘要:目的 使用5型腺病毒(AdS)感染小鼠模型来研究肝脏NKT细胞(natural killer Tcell)在肝损伤早期的免疫调节机制.方法 C57BL/6小鼠尾静脉注射1.5×109PFU和3×109PFUAdS病毒以构建两个剂量组病毒感染的小鼠肝损伤模型,通过观察病毒感染后5 d内小鼠肝组织病理学及小鼠血清丙氨酸转氨酶/天门冬氨酸转氨酶(ALT/AST)水平改变来判断肝损伤程度,使用流式细胞术(FACS)分析感染5 d内肝单个核细胞亚群比例、NKT细胞表面FasL表达水平以及NKT细胞合成IL-4和IFN-γ水平的变化,应用RT-PCR检测小鼠肝内趋化因子及趋化因子受体表达水平.结果 高滴度(3×109 PFU)的AdS病毒感染小鼠1 d后,小鼠肝脏内NKT细胞明显增加,其表面FasL表达上调,肝脏NKT细胞合成IL-4和IFN-γ的水平明显增加,肝组织内淋巴细胞浸润明显;低滴度AdS病毒(1.5×109PFU)感染小鼠后,肝脏NKT细胞比例变化不明显,CD8+T细胞在肝脏的浸润明显弱于高滴度AdS病毒感染;RT-PCR检测结果 显示:3×109PFU AdS病毒感染2 d后,小鼠肝内活化后可调节的及正常的T细胞分泌的趋化因子(RANTES)、人干扰素诱导蛋白10(IP-10)以及巨噬细胞炎症蛋白(MIP)-1β表达增加,3d后相关趋化因子受体CCR5、CCR1、CXCR3表达上调.结论 NKT细胞在淋巴细胞向肝脏趋化的过程中起重要的作用,这种作用与病毒感染诱导NKT细胞合成IL-4和IFN-γ及上调其表面的FasL,从而促进肝细胞内IP-10、Mig等趋化因子的产生有关.%Objective To study the immune regulatory effect of natural killer cell(NKT) in the early stage of murine liver injury induced by type 5 adenovirus(Ad5). Methods Animal models were con-structed by injected C57BL/6 mice with 1.5×109-3×109 PFU Ad5 into the tail vein. Liver injury of mouse at day 0, 1, 2, 3, 4, 5 after infection was determined by HE staining and serum ALT/AST(alanine amin-otransferase/aspartate aminotransferase) level. Flow cytometry analysis was used to measure the proportion of lymphocytes, expression of Fas/FasL on the surface of NKT cells and level of IL-4, IFN-γ/in NKT cell plasma in the infected mouse liver. RT-PCR was applied to semi-quantify the chemokines and their receptors mRNA in infected mouse liver. Results NKT cells of mouse increased significantly at day 1 after infected with high titer Ads(3×109 PFU), expression of FasL on NKT cell and plasma IL-4, IFN-γ/level in NKT cells were also up-regulated, hence the obviously infiltration of lymphocytes in routine liver. Comparing with high titer Ads infection, low titer Ads infection (1.5×109 PFU) lead to little change of NKT cell proper-tion, and fewer infiltration of lymphocytes in murine liver. Hepatic chemokine RANTES, 1P-10, and MIP-1β mRNA expression in C57BL/6 was up-regulated 2 d after intravenous administration of 3×109 PFU Ad5. Corresponding chemokine receptor CCR5, CCR1, CXCR3 mRNA expression was up-regulated 3 d after in-fection. Conclusion NKT cells play an important role in lymphocytes recruitment into the liver of mouse in-fected with AdS, which may relate to up-regulatio of the plasma IL-4, IFN-γ level and expression of FasL of NKT cells, therefore facilitating the production of chemokines, e.g. IP-10 and Mig.