2007～2008年流感监测季北京地区H3N2亚型流感病毒抗原性与HA1基因特性分析

Antigenic and genetic analysis of haemagglutinin gene of influenza virus(H3N2) circulating in Beijing during 2007～2008

目的：了解2007～2008年流感监测季北京地区分离的H3N2亚型流感病毒抗原性及血凝素基因变异情况。方法：选取2007—2008年流感监测季中分离的首株H3N2亚型毒株及其后不同时间、不同地点共9株毒株，通过单向血凝抑制试验进行抗原性分析；测定血凝素基因的HA1区核苷酸序列并推导出其氨基酸序列，进行基因进化特性分析。结果：与我国代表株A／江西／东湖／312／2006本身的血凝抑制效价相比，9株病毒中3株有4倍及以上差异。HA1区核苷酸序列和氨基酸序列分析表明，有部分毒株的氨基酸发生下述替换：3L→F、53 D→N、57 Q→H、157 L→S、158 K→R、171 N→K、173 K→N、182 V→I、194P→L、261 R→Q、272 A→V、291 N→D、299 K→R；其中53、157、158、171、173、194位氨基酸位于抗原决定簇。结论：北京地区2007～2008年流感监测季分离的H3N2亚型流感病毒有部分毒株已发生抗原性及基因特性的改变。

Objective ：To analyze the antigenic and genetic characteristics of influenza virus （H3N2） circulating in Beijing during 2007 -2008. Methods：9 H3N2 virus isolates were selected according to the different time and location in Beijing which were isolated during 2007 - 2008 influenza virus surveillance season. Single way hemagglutination inhibition （HI） tests were firstly used to determine antigenic drift. The HA1 domain of HA gene of those virus isolates were then sequenced in order to analyze the gene characteristic. Results：Single way HI test results revealed that 33 % of isolates showed 4 folds or more HI titer difference compared to A/Jiangxi/Donghu/312/2006 （H3N2） itself （national reference strain in 2007）. The nucleic acid and amino acid sequence data of HA1 domain showed that there were some shifts of amino acids in some isolates. The positions were 3 L→F,53 D →N,57 Q→H,157 L→S,158 K→R,171 N→K,173 K→N,182 V→I,194P→L,261 R→Q,272 A→W,291 N→D,299 K→ R. The 53, 157,158,171,173,194 were located in the antigenic site. Conclusion：The HA1 domain of HA gene of influenza virus （H3N2） isolated during 2007 -2008 in Beijing show mutation and antigenic drift.