摘要
目的:比较并探讨日本脑炎病毒Beijing-1株和登革2型病毒43株对宿主细胞内IFN-α介导的信号转导通路抑制作用的机制。方法:采用含萤火虫荧光素酶(Luciferase,Luc)报告基因的重组载体pISRE-Luc,通过检测IFN刺激应答元件(IFN-stimulated response element,ISRE)活性对病毒感染细胞内IFN-α介导的JAK-STAT信号转导通路的抑制作用进行定量分析。利用间接免疫荧光法观察在IFN-α作用下病毒感染细胞内STAT1分子的分布情况。进一步采用Western印迹分别检测在这两种病毒感染状态下宿主细胞内STAT1、JAK1和TYK2的磷酸化水平。结果:感染日本脑炎病毒和登革病毒的细胞在IFN-α作用下,ISRE活性与对照组相比均显著下降,而且日本脑炎病毒对宿主细胞内ISRE活性的抑制程度明显强于登革病毒;进一步研究发现,日本脑炎病毒可通过抑制JAK1和TYK2两种激酶的活性,降低STAT1的磷酸化水平,阻碍STAT1的核转运;而登革病毒则只抑制TYK2激酶的活化,降低STAT1的磷酸化及核转运水平。结论:日本脑炎病毒和登革病毒可通过不同的作用机制抑制IFN-α介导的JAK-STAT信号转导通路。
Objective：To compare and investigate the mechanism of the inhibition of IFN-α induced signaling transduction pathway by JEV, Beijing-1 strain and DEN2, 43 strain. Methods： pISRE-Luc with firefly luciferase reporter gene was used to determine ISRE activity level and quantify the suppressive degree of JAK-STAT signaling in infected cells by JEV or DEN2. Then the intracellular STAT1 status of JAK-STAT signaling in the cells infected by JEV or DEN2 after IFN-α treatment was observed under a fluorescence microscope. The STAT1, JAKI and TYK2 phosphorylation were analyzed in the cells infected by JEV or DEN2 through Western blotting. Results：The ISRE activity level significantly decreased in the cells infected by JEV or DEN2, and the ISRE activity by JEV was much lower than that by DEN2. The levels of tyrosine phosphorylated TYK2 （p-TYK2） and JAK1 （p-JAK1） in response to IFN-α stimulation were blocked in the cells infected by JEV, however, in the DEN2 infected cells, the levels of p-TYK2 rather than p-JAK1 in response to IFN-α stimulation were inhibited, resulting in the reduced levels of STAT1 tyrosine phosphorylation （ p-STAT1 ） upon IFN-α stimulation. The nuclear translocation of the endogenous STAT1 was inhibited. Conclusion：JEV or DEN2 may be able to inhibit IFN-α signaling in the infected cells through the different mechanisms.
出处
《军事医学科学院院刊》
CSCD
北大核心
2008年第3期207-210,共4页
Bulletin of the Academy of Military Medical Sciences
基金
国家自然科学基金项目(30600530)
