A型塞内卡病毒2C蛋白通过STING调控IFNβ、TNF-α和IL-6的表达  

Protein 2C of Senecavirus A regulates the expression of IFNβ,TNF-αand IL-6 through STING

作　　者：王梦瑶 张瑞 谭小雨 游青 马潇雨 周泷 柏玲 张志雄 李彦敏 张志东 WANG Mengyao;ZHANG Rui;TAN Xiaoyu;YOU Qing;MA Xiaoyu;ZHOU Long;BAI Ling;ZHANG Zhixiong;LI Yanmin;ZHANG Zhidong(College of Animal and Veterinary Sciences,Southwest Minzu University,Chengdu 610041,Sichuan,China;State Key Laboratory of Veterinary Etiological Biology,Lanzhou Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Lanzhou 730046,Gansu,China)

机构地区：[1]西南民族大学畜牧兽医学院,四川成都610041 [2]中国农业科学院兰州兽医研究所家畜疫病病原生物学国家重点实验室,甘肃兰州730046

出　　处：《微生物学通报》2023年第5期2087-2098,共12页Microbiology China

基　　金：中央高校基本科研业务费专项基金项目(2021115);西南民族大学高层次人才科研专项基金项目(16011211013);四川省自然科学基金(2022NSFSC0073);甘肃省科技计划国际科技合作类项目(20YF3WA008)。

摘　　要：【背景】A型塞内卡病毒(Senecavirus A,SVA)是新发猪塞内卡病毒病的病原,属于小核糖核酸病毒科(Picornaviridae)塞内卡病毒属(Senecavirus)的单股正链RNA病毒。可引起新生仔猪死亡和成年猪口、蹄部出现水泡。先天免疫是宿主抵御病毒入侵的第一道防线,但SVA与宿主抗病毒先天免疫的相互作用机制尚不清楚。【目的】探究SVA非结构蛋白2C在先天免疫应答中的作用机制。【方法】利用SVA感染和通过在猪PK-15细胞中过表达SVA 2C蛋白,利用RT-qPCR和Western blotting分析2C蛋白对细胞因子表达及其关键信号通路的影响。【结果】RT-qPCR检测发现,SVA感染PK-15细胞导致IFNβ、TNF-α和IL-6表达的显著升高;同时,SVA感染导致TBK1和NF-κB的磷酸化。进一步的研究发现,SVA的2C蛋白能够激活TBK1和NF-κB磷酸化,并诱导IFNβ、TNF-α和IL-6的表达;2C蛋白能够激活抗DNA病毒感染关键蛋白干扰素基因刺激因子(stimulator of interferon genes,STING)磷酸化,敲除STING抑制TBK1、NF-κB的磷酸化和IFNβ、TNF-α、IL-6的表达。【结论】本研究初步揭示了SVA 2C蛋白通过激活STING诱导天然免疫应答的作用机制,揭示了STING参与调控RNA病毒SVA介导的免疫应答的功能,为抗病毒药物和疫苗的研发提供了理论基础。[Background]Senecavirus A(SVA)is a novel pathogen that causes an infectious viral disease in pigs.SVA,a member of the genus Senecavirus of the family Picornaviridae,has a single-stranded positive-sense RNA genome.SVA can infect pigs of all ages,causing neonatal mortality and blisters on the feet and in or around the mouth of pigs.Innate immunity is the first line of host defense against viral invasion,while the role of the mechanism of the interaction between SVA and host innate immune responses remains unknown.[Objective]To investigate the role of the 2C protein of SVA in innate immune responses.[Methods]RT-qPCR and Western blotting were employed to analyze the effect of 2C protein on cytokine expression and signaling pathway in host PK-15 cells overexpressing 2C protein or were infected with SVA.[Results]The infection of SVA significantly up-regulated the expression of interferon beta(IFNβ),tumor necrosis factor-alpha(TNF-α),and interleukin-6(IL-6)in host PK-15 cells.Meanwhile,SVA infection resulted in the phosphorylation of TANK-binding kinase 1(TBK1)and Nuclear factor-kappa B(NF-κB).Further studies revealed that 2C protein activated TBK1 and NF-κB and induced the expression of IFNβ,TNF-α,and IL-6.In addition,2C protein activated the stimulator of interferon genes(STING),a key protein against DNA virus infection.The knockout of STING suppressed the phosphorylation of TBK1 and NF-κB as well as the expression of IFNβ,TNF-α,and IL-6.[Conclusion]This study preliminary reveals that the 2C protein of SVA activates STING to induce the innate immune responses.The findings uncover the regulatory role of STING in the RNA virus SVA-mediated immune response,which provide a theoretical basis for the research and development of antiviral drugs and vaccines.

关 键 词：A型塞内卡病毒 天然免疫应答 2C蛋白 细胞因子 干扰素基因刺激因子 

分 类 号：S852.65[农业科学—基础兽医学]