2000～2002年我国流行的甲3(H3N2)亚型流感病毒抗原性及基因特性的研究

Antigenic and genetic characterizations of group A influenza viruses (H3N2) circulated in men in China during 2000-2002

目的 了解 2 0 0 0～ 2 0 0 2年我国流行的甲 3流感病毒HA基因突变及其抗原变异情况。方法 鸡胚传代流感病毒 ,收获尿囊液作为抗原性分析抗原并提取病毒的RNA ,进行逆转录—聚合酶链反应 (RT PCR) ,扩增产物用纯化试剂盒纯化后测序 ,用MegAlign软件进行基因种系发生树分析。结果 与A 武汉 35 9 1995 (H3N2 )、A Sydney 5 1997(H3N2 )相比 ,2 0 0 0～ 2 0 0 2年我国分离到的甲 3亚型流感病毒的血凝素重链区氨基酸序列存在差异。 2 0 0 1～ 2 0 0 2年分离到的甲 3毒株与 2 0 0 0年分离出的毒株的血凝素蛋白重链区 (HA1)氨基酸序列有 4个位点差异 ,它们分别位于 83、186、2 0 2和 2 2 2位 ,其中 83和 186分别位于抗原决定簇E和B区 ,其余均位于受体结合位点 (RBS)的左臂。结论 2 0 0 0～ 2 0 0 2年分离到的甲 3亚型流感病毒的基因特性发生突变并导致其抗原性发生漂移。

Objective To understand the antigenic and genetic characteristics of influenza A(H3N2)viruses circulated in man in China from 2000 to 2002. Methods Embryonated chicken eggs inoculated with virus for amplification of viral yield.The harvesting egg allantoic fluids with influenza viruses were provided for testing antigen and RNA extraction. Virion RNA was transcribed into cDNA by reverse transcriptase,cDNA amplified by PCR,and the product of PCR was purified. Afterward RNA sequence analysis was performed by the dideoxynucleotide chain termination method using synthetic oligodeoxynucleotide primers. Finally the phylogenetic tree was analyzed with MegAlign soft ware. Results The H3N2 viruses isolated during 2000-2002 were different in amino acid sequences on HA1 domain protein molecule from those of A/Wuhan359/1995(H3N2) as well as those of A/Sydney/7/1997(H3N2)strains. There were four different positions of amino acid sequence on HA1 domain protein molecule among the H3N2 viruses isolated in 2000 and during 2001-2002. They located at 83,186,202,222 and 225 position,respectively. Of them 83 and 186 were in antigenic determinant E and B,respectively. The others located at left wall of the receptor binding site (RBS). Conclusion From the end of 2001 to the beginning of 2002,the influenza epidemic in Northern China caused by H3N2 virus was due to occurrence of antigenic and genetic changes of influenza A(H3N2) virus.