狂犬病病毒强、弱毒株糖蛋白调节Ⅰ型干扰素作用的差异分析

The different regulatory effect of glycoproteins from virulent and attenuated strain of rabies virus on type I interferon signaling pathway

【目的】狂犬病(Rabies)是由狂犬病病毒(Rabies virus,RABV)引起的一种高致死性人兽共患传染病。Ⅰ型干扰素(IFN-I)通路在抵抗RABV感染中发挥重要作用。RABV可通过磷蛋白及核蛋白的功能逃逸IFN-I的抗病毒作用,本研究旨在探讨对RABV的致病性有重要影响的糖蛋白(Glycoprotein,G)在调节IFN-I通路方面扮演怎样的角色。【方法】将RABV弱毒株Hep-Flury的G基因替换成致病株CVS-11的G基因,拯救得到重组病毒HepG,分析Hep-Flury、CVS-11和HepG这3种毒株在体内和体外感染对IFN-I通路激活和调控的差别,比较它们在神经细胞中对抗IFN-I抗病毒作用的差异性。【结果】替换了CVS-11的G基因后,重组病毒HepG致病力增强,能够100%致死小鼠,在鼠脑中的增殖水平显著高于亲本株Hep-Flury。在感染鼠脑早期及体外神经细胞时,弱毒株Hep-Flury能够较快地激活IFN-I通路相关基因的表达,重组病毒HepG的激活能力介于HepFlury和CVS-11之间。利用Poly(I:C)激活神经细胞的IFN-I通路后,Hep-Flury的增殖被显著抑制,CVS-11和HepG的复制几乎不受影响,表现出一定的抵抗能力。【结论】RABV的G蛋白在调节和抵抗IFN-I通路方面发挥重要功能,为进一步探究RABV致病毒株的G蛋白如何协助病毒在中枢神经系统中逃逸IFN-I提供了线索和依据。

【Objective】Rabies is a highly lethal zoonotic infectious disease caused by rabies virus(RABV).Type I interferon(IFN-I)pathway plays an important role in resisting RABV infection.RABV can escape the antiviral effect of IFN-I through the function of its phosphoprotein and nucleoprotein.The aim of the study was to investigate the role of glycoprotein(G),which has an important impact on the pathogenicity of RABV,in regulating IFN-I pathway needs more comprehensive exploration.【Method】This study replaced the G gene of the RABV attenuated strain Hep-Flury with the G gene of the pathogenic strain CVS-11 to rescue and acquire the recombinant virus HepG.We analyzed the differences in the activation and regulation of IFN-I pathway in vivo and in vitro infected with Hep-Flury,CVS-11 and HepG,and compared the differences of these virus strains in fighting against antiviral effect of IFN-I in nerve cells.【Result】After replacing G gene,the recombinant virus HepG had enhanced pathogenicity,was able to kill 100%of mice and the proliferation level in the mouse brain was significantly higher than that of the parental strain Hep-Flury.While infecting mouse brain early and in vitro neuronal cells,the attenuated strain Hep-Flury was able to activate the expression of IFN-I pathway-related genes faster,and the activation ability of HepG was between that of Hep-Flury and CVS-11.After activation of the IFN-I pathway in neuronal cells using Poly(I:C),the proliferation of Hep-Flury was significantly inhibited,and the replication of CVS-11 and HepG was almost unaffected,showing some resistance.【Conclusion】G protein of RABV plays an important role in regulating and resisting the IFN-I pathway,providing the clue and evidence for further exploring how the G protein of RABV pathogenic strains helps the virus escape IFN-I pathway in the central nervous system.