宁夏H3N2流感病毒血凝素基因分子特征分析  

Epidemiology and molecular evolutional characteristic of hemagglutinin gene of influenza A(H3N2)viruses in Ningxia

作　　者：孙晓强[1] 穆婷 温秋芳[1] 马学旻[1] 曹慜[1] 袁芳[1] 杨东智[1] 马玲[1] SUN Xiao-qiang;MU Ting;WEN Qiu-fang;MA Xue-min;CAO Min;YUAN Fang;YANG Dong-zhi;MA Ling(Ningxia Center for Disease Control and Prevention,Yinchuan,Ningxia 750004,China)

机构地区：[1]宁夏疾病预防控制中心,宁夏银川750004

出　　处：《现代预防医学》2021年第11期2046-2050,共5页Modern Preventive Medicine

基　　金：宁夏自然科学基金项目(2020AAC03434)。

摘　　要：目的了解2014—2020年宁夏H3N2流感病毒血凝素(Haemagglutimin,HA)基因变异情况,为宁夏的流感防控提供科学依据。方法选取2014—2020年宁夏分离的30株H3N2流感毒株,提取病毒RNA,采用RT-PCR方法扩增HA片段并测序,利用生物信息软件对测序结果进行比对分析。结果与疫苗株A/Texas/50/2012比较,宁夏H3N2流感毒株抗原表位在A区、B区和C区均有氨基酸变异,D区和E区抗原位点相对保守,未监测到变异。所有毒株在A区R142G/K、N145S,B区F159S/Y、P198P/S及C区N278K均发生变异。所有毒株受体结合位点左壁发生N225D变异,2016年和2017年部分毒株前壁发生T131K变异,2019—2020年宁夏流感毒株前壁发生T135K和S137F变异,底壁发生W153F变异,其他位点未发生变异。糖基化位点变异多发生于A区抗原位点和受体结合位点左壁、前壁及底壁。半胱氨酸相关位点均未发现氨基酸替换和插入。与分支带代表株比较,2014年、2015年及2016年部分毒株位于3C.3a分支,2016年部分毒株和2017年毒株位于3C.2a1分支,2019年和2020年毒株位于3C.2alb分支。结论宁夏H3N2流感病毒HA蛋白重要氨基酸位点的变异表现出遗传多态性,在基因进化上呈现多分枝进化的特点,在抗原特异性、毒力和感染性上有可能已经发生变化。Objective To analyze the hemagglutinin(HA) genetic characteristics of influenza A(H3 N2) virus during 2014-2020 in Ningxia to provide scientific basis for influenza prevention and control. Methods Viral RNAs of 30 H3 N2 strains were extracted, and the HA fragment was amplified by RT-PCR and sequenced.Bioinformatics software was used to compare and analyze the sequencing results. Results Compared with the vaccine strain A/Texas/50/2012, the influenza A(H3 N2) virus in Ningxia amino acid substitutions took place in antigenic determinants A, B and C, and the antigenic sites in the D and E regions were relatively conservative. All strains had mutations in A region(R142 G/K, N145 S), B region(F159 S/Y, P198 P/S)and C region(N278 K). All strains had mutations in the left wall(N225 D), T131 K mutation occurred in the front wall of some strains in 2016 and 2017. In 2019-2020, Ningxia influenza strains had T135 K and S137 F mutations in the front wall, W153 F mutation in the bottom wall, and no mutations in other sites. Glycosylation site variation mostly occurred in the left, front and bottom walls of the antigen site and receptor binding site in the A region. There were no amino acid substitutions and insertions at cysteine-related sites. Compared with the representative strains in the branching zone, the influenza A(H3 N2) virus in 2014, 2015 and 2016 belonged to the 3 C.3 a branch, the influenza A(H3 N2) virus in 2016 and 2017 belonged to the 3 C.2 a1 branch, and the influenza A(H3 N2) virus in 2019 and 2020 belonged to 3 C. 2 alb branch. Conclusion The variations of the influenza A(H3 N2) virus in Ningxia showed genetic polymorphism. It was characterized by multi-branch evolution in genetic evolution, there may be major variations in antigenicity, virulence and infectivity.

关 键 词：H3N2流感病毒 血凝素 基因变异 进化 

分 类 号：R117[医药卫生—公共卫生与预防医学]