IBV-NSP16通过调控STAT3/IL-6/SOCS3信号通路促进病毒复制  

Nonstructural protein 16 of infectious bronchitis virus facilitates viral replication via regulating STAT3/IL-6/SOCS3 signal pathway

作　　者：雷尧 王真 方守国[1] LEI Yao;WANG Zhen;FANG Shou-guo(College of Agriculture,Yangtze University,Jingzhou 434025,China;Medical Science Center,Yangtze University,Jingzhou 434025,China)

机构地区：[1]长江大学农学院,湖北荆州434025 [2]长江大学医学部,湖北荆州434025

出　　处：《中国兽医科学》2023年第11期1424-1430,共7页Chinese Veterinary Science

基　　金：国家自然科学基金面上项目(31572490)。

摘　　要：冠状病毒编码的非结构蛋白16(NSP16)在结构和功能上相对保守。NSP16具有2’-O-MTase活性,类似真核宿主的mRNA加帽体系,可使病毒RNA的5’-端形成帽子结构,起到稳定病毒mRNA和实现免疫逃逸的作用。为了研究IBV编码的NSP16的生物学功能,我们利用反向遗传学方法,构建并获得了丧失甲基转移酶活性的突变体rIBV-D128A,发现其致病力和复制速率比野生型rIBV弱。随后运用qRT-PCR和Western-blot等分子生物学方法,通过检测rIBV和rIBV-D128A感染H1299细胞中天然免疫反应相关基因的差异表达,以明确NSP16的生物学功能。研究结果显示,相比于rIBV,rIBV-D128A感染增强了细胞中STAT3的磷酸化水平,显著上调了SOCS3蛋白和炎症因子IL-6的表达。这些结果表明,IBV-NSP16可通过调控STAT3/SOCS3/IL-6信号通路,创造出有利于IBV复制的细胞环境。研究结果为进一步明确IBV nsp16生物学功能提供了理论依据。The non-structural protein 16 encoded by coronavirus is relatively conservative in structure and function.NSP16 has 2′-O-MTase activity,which is similar to the mRNA capping system of eukaryotic host.It can form a cap structure at the 5′end of viral RNA,which plays an important role in virus immune escape and protection of newly synthesized viral RNA from degradation.In order to study the biological function of NSP16 encoded by avian infectious bronchitis virus,we constructed and obtained a mutant rIBV-D128A which lost methyltransferase activity by reverse genetic method.It was found that its pathogenicity and replication rate were weaker than those of wild type rIBV.Then the molecular biological methods such as qRT-PCR and Western-blot were used to detect the differential expression of innate immune response-related genes in rIBV and rIBV-D128A infected H1299 cells in order to clarify the biological function of NSP16.The results showed that compared with rIBV,rIBV-D128A infection enhanced the phosphorylation level of STAT3 and the expression of SOCS3 protein and IL-6 in H1299 cells,suggesting that IBV-NSP16 could create a cellular environment conducive to IBV replication by regulating the STAT3/SOCS3/IL-6 signal pathway.The results provide a theoretical basis for further clarifying the biological function of IBV-NSP16.

关 键 词：禽传染性支气管炎病毒 非结构蛋白16 病毒复制 H1299细胞 

分 类 号：S852.659.6[农业科学—基础兽医学]