2004—2005年中国B型流感病毒抗原性及基因特性研究

Antigenic and genetic study of influenza virus B circulated in China in 2004—2005

目的阐明2004—2005年中国流行的B型流感病毒血凝素抗原性及其基因变异情况。方法对2004—2005年分离的B型毒株先进行单向血凝抑制试验;在此基础上选取不同时间、地点的B型流感毒株进行血凝素基因HA1区核苷酸序列测定并推导出其氨基酸序列,然后进行基因进化特性分析。结果2004—2005年我国人群中同时流行着B型Yamagata系和Victoria系毒株。Yamagata系毒株与B/Shanghai/361/02比较,2004年有3·7%病毒单向血凝抑制效价有4倍以上差异,2005年有4·5%病毒单向血凝抑制效价有4倍以上差异,并且在血凝素基因HA1区发生9个氨基酸替换,在196为增加一个糖基化位点。Victoria系毒株与B/Hongkong/330/01比较,2004年有8·5%病毒单向血凝抑制效价有4倍以上差异,2005年有20·6%病毒单向血凝抑制效价有4倍以上差异,并且在HA1区发生9个氨基酸替换,在197位增加一个糖基化位点。结论2004—2005年我国人群中流行的B型流感病毒的抗原性与B/Shanghai/361/02、B/Hongkong/330/01相比抗原性已经发生了变化。

Objective To analyze the genetic and antigenic characteristics of hemagglutinin （HA） gene of human influenza B virus isolated from the mainland of China since 2004—2005. Methods The single-way hemagglutination inhibition （HI） tests were used to test the antigenic characteristics, and the HA1 gene was sequenced based on the antigenic results. Results The Yamagata-like and Victoria-hke viruses co-circulated in 2004—2005. For the Yamagata-like virus, the single-way HI results showed that 3.7% and 4.5% of the viruses had 4-fold greater HI titer difference compared with B/Shanghai/361/02 in 2004 and 2005, respectively. The HA1 sequence data showed that the virus had amino acid mutation, and there was one more glycosylation site at 196th site. For the Victoria-like virus, the single-way HI results showed that 8.5% and 20.6% of the viruses had 4-fold greater HI titer difference compared with B/Hong kong/330/01 in 2004 and 2005, respectively. The HA1 sequence data showed that the virus had replacement of 9 amino acids, and there was one more glycoaylation site at 197th site. Conclusion The results showed that influenza B viruses had changing antigenic and genetic characteristics compared with B/Shanghai/361/02, B/Hong kong/330/01 in 2004—2005.