2009年新型甲型H1N1流感病毒基质蛋白基因进化的新探讨

摘要

目的 探讨甲型H1N1流感病毒基质蛋白(M)基因的进化规律及M2蛋白的氨基酸替代情况.方法 从NCBI数据库下载甲型H1N1病毒M基因179条进行预分析,最终选取50条采用MEGA 4.0软件对其进行比对,采用NJ法构建进化树,同时采用MEGA 4.0软件对M2蛋白氨基酸序列进行比对.结果 不同地区新型甲型H1NI流感病毒M基因同源性高,达99.6%～100.0%,但与历史上流行的H1N1和H3N2流感病毒M基因差异较大,仅与1999-2002年间香港地区流行的H3N2亚型猪流感病毒同源性较近,为96.7%~97.7%.2009年流行的新型甲型H1N1流感病毒与历年来流行的H1N1人流感病毒相比,在第11、13、14、16、20、28、31、43、54、57、77、78、82、86、89、93位氨基酸位点发生了变异;与历年来流行的H1N1禽流感病毒相比,在第13、14、16、31、43、55、77、89位氨基酸位点发生了变异;与H1N1猪流感病毒相比,在第13、14、19、43、55位氨基酸位点发生了变异.2009年流行的甲型H1N1流感病毒与历年来流行的H3N2人流感病毒相比,在第11、13、16、20、28、31、43、54、57、77、78、82、86、89、93位氨基酸位点发生了变异;与历年来在欧亚大陆流行的猪流感病毒相比,所比较的19个位点均有部分毒株发生变异;而与1999-2002年间在香港流行的H3N2猪流感病毒相比,仅在第13、14、21、43位氨基酸位点发生变异.结论 此次新型甲型H1N1流感病毒M基因可能由香港地区流行的H3N2猪流感病毒重组而来.M2蛋白胞外编码区氨基酸位点发生变异,提示在疫苗研制方面应注意由此带来的影响.跨膜区的突变可能是导致此次新型甲型H1N1流感病毒对金刚烷胺类特异性抗病毒药物产生耐药性的原因,第43位氨基酸位点可能为引起此次耐药的主要位点.%Objective To elucidate the evolution characteristics of the matrix protein (M) gene and the atnino acid substitutions of M2 protein of the emerging novel A/H1N1 influenza pandemic virus in 2009. Methods The matrix protein genes of 179 A/H1N1 and H3N2 influenza virus strains were downloaded from NCBI database, and protein sequences alignment by MEGA4.0 software was undertaken in 50 of them. The phylogenetic tree was constructed by NJ method. Results The matrix protein gene showed high homology in the novel A/H1N1 virus isolated from different locations, the identity was 99. 6% -100. 0%, while the matrix protein gene showed significant difference with that of previous influenza H1N1 and H3N2 virus except the H3N2 swine influenza virus spread in Hong Kong from 1999 to 2002 (96. 7% - 97. 7%). Compared with the amino acid sequence of M2 protein of reference human A/H1N1 virus strains isolated from 1918 to 2008, the amino acid substitutions appeared in novel A/H1N1 virus at 16 sites, i. e. 11, 13, 14, 16, 20, 28, 31, 43, 54, 57, 77, 78, 82, 86, 89 and 93. Compared with the sequences of swine and avian A/H1N1, the amino acid substitutions appeared at sites 13, 14, 19, 43, 55 and 13, 14, 16, 31, 43, 55, 77, 89, respectively. Compared with the sequences of reference human H3N2 virus strains, the amino acid substitutions appeared in novel A/H1N1 virus at 15 sites, i. e. 11, 13, 16, 20, 28, 31, 43, 54, 57, 77, 78, 82, 86, 89, and 93. However, compared with the Hong Kong swine H3N2 virus strains isolated from 1999 to 2002, amino acid substitutions appeared in novel A/H1N1 virus at only 4 sites, i.e. 13, 14, 21, and 43. Conclusions The matrix protein genes of the novel A/H1N1 influenza virus may be reassorted with swine H3N2 influenza virus spread in Hong Kong. The amino acid substitution at M2 protein-coding region is of significance for vaccine development, and may contribute to amantadine resistance of the novel A/H1N1 influenza virus. The 43rd amino acid site may play a critical role in amantadine resistance.