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研究2013~2014年中国大陆分离到4株不同基因型麻疹野毒株血凝素蛋白(HA)编码基因的基因和氨基酸特征及变异程度。选取2013~2014年我国优势基因型H1a1株,输入基因型B3、D8和D9各1株作为代表株,核酸提取,采用逆转录-聚合酶链反应(RT-PCR)扩增H基因编码区全序列(1 854bp)并测序,使用sequencher5.0进行序列拼接,并与GenBank下载的H1基因型4株、B3基因型和D8基因型各8株、D9基因型2株及中国A基因型麻疹疫苗株沪191(S191)和长47(C47)H基因全序列进行比较分析,使用MEGA5.0比对并构建亲缘性关系树及分析其核苷酸和氨基酸差异。4株不同基因型野毒株与A基因型疫苗株H基因核苷酸和氨基酸同源性为94.2%~96.7%,95.4%~96.7%,氨基酸差异数为20~28,其中Beijing14-1(H1a)与A基因型疫苗株H基因同源性最低。H1a毒株与1993~1994年分离的毒株核苷酸同源性较高为97.7%~98.2%。Beijing14-1(H1a)和Shanghai14-1(B3)第240位点氨基酸位点由S→N,导致HA蛋白的1个N-糖基化位点丢失。4株野毒株与中国A基因型疫苗株H基因核苷酸和氨基酸同源性较高,且重要中和抗原位点未出现明显突变。从基因层面上分析A基因型疫苗株对我国流行的H1a亚型及B3、D8和D9输入性基因型野毒株感染仍具有较好的保护效果。
To study the gene and amino acid characteristics of HA gene encoding four wild type measles virus isolates isolated in mainland of China from 2013 to 2014. The dominant H1a1 strain of our country from 2013 to 2014 was selected and one strain of genotypes B3, D8 and D9 was input as the representative strain. Nucleic acid was extracted and the coding region of H gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) (1 854bp) were sequenced and sequenced using sequencher 5.0. Four strains of H1, 8 of B3 and D8 genotypes, 2 of D9 and 2 of China A genotype were downloaded from GenBank. The sequences of strain H191 (S191) and length 47 (C47) H were comparatively analyzed. The alignment of MEGA5.0 was constructed and the nucleotide and amino acid differences were analyzed. The nucleotide and amino acid homologies of H gene of four strains with different genotypes and those with genotype A were 94.2% ~ 96.7%, 95.4% ~ 96.7%, and the number of amino acids was 20 ~ 28, among which Beijing14-1 ( H1a) had the lowest homology with H gene of A genotype vaccine strain. The nucleotide homology between H1a strain and strains isolated from 1993 to 1994 was higher from 97.7% to 98.2%. The amino acid position at the site 240 of Beijing14-1 (H1a) and Shanghai14-1 (B3) is changed from S → N, resulting in the loss of one N-glycosylation site of the HA protein. The homology of nucleotide and amino acid of H gene between 4 strains of wild type and Chinese A genotype vaccine strain was high, and no significant mutation was found in the site of important neutralizing antigen. Genotype analysis of A genotype vaccine strains still have good protective effect on the epidemic H1a subtype and the wild type B3, D8 and D9 genotypes in China.