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目的研究吉林省2009年麻疹病毒流行株的核蛋白(Nucleoprotein,N)抗原表位变异。方法对吉林省2001～2009年麻疹病例的咽拭子标本,用逆转录-聚合酶链反应(Reverse Transcription-Polymerase Chain Reaction,RT-PCR)扩增N蛋白基因片段后测序,分析2001～2009年麻疹病毒株核苷酸、氨基酸变异以及抗原表位变异。结果吉林省2001～2009年流行的麻疹病毒均属于H1基因型,但2009年的麻疹病毒流行株在基因树上处于一个相对独立的小分支。与2001～2008年的麻疹病毒相比,其N蛋白基因序列推导的氨基酸均有共同的3个氨基酸变化,其中在457位点由丝氨酸至甘氨酸的变异,恰好是N蛋白的抗原决定簇之一。结论吉林省2001～2008年流行的麻疹病毒在N蛋白基因上无明显差别,2009年所有麻疹病毒N蛋白在抗原表位第457位点均发生氨基酸变异,提示要关注N蛋白氨基酸变异状况以及变化趋势、N蛋白氨基酸变异与抗原变异的关系以及由其产生的影响。
Objective To study the variation of the antigenic epitopes of nucleoprotein (N) in 2009 measles virus epidemic strains in Jilin Province. Methods Throat swab samples of measles cases from 2001 to 2009 in Jilin Province were amplified by reverse transcription-polymerase chain reaction (RT-PCR) and sequenced. Measles strain nucleotide, amino acid variation and epitope variation. Results All the measles viruses in Jilin Province from 2001 to 2009 belonged to the H1 genotype. However, the measles virus epidemic strain in 2009 was in a relatively independent small branch in the gene tree. Compared with the measles virus from 2001 to 2008, all the amino acids deduced from the N protein gene sequence shared three common amino acid changes, of which the mutation from serine to glycine at position 457 happened to be one of the antigenic determinants of N protein . Conclusions There is no significant difference in the N protein gene of measles virus from 2001 to 2008 in Jilin Province. In 2009, amino acid variation of all the measles virus N protein occurred at the 457th epitope, suggesting that attention should be paid to the variation of N protein amino acid variation Trends, N Protein Amino Acid Variants and Antigen Variants, and Their Impact.