风疹病毒松叶株E1基因遗传变异研究

目的 研究风疹病毒(rubella vires,RV)疫苗松叶株(Matsuba)El基因遗传与变异特点,在基因水平评估Matsuba株生产的疫苗对流行株的保护效果. 方法 将风疹病毒松叶株毒种RV14在原代兔肾细胞连续传至第23代,取RV14、RV16、RV17、RV18、RV23代进行研究分析.利用RT-PCR方法扩增松叶株不同代次的E1蛋白基因,将E1基因与pGEM-T载体连接,获得风疹病毒E1基因的克隆并测序,对各代次病毒的E1基因与风疹病毒疫苗Matanba株(GenBank登录号:D50673)及其他参考株的E1基因序列进行比对分析. 结果 风疹病毒Matsuba株传至23代时仍有很高的同源性,RV14、RV16、RV18代次病毒与D50673的核苷酸和氨基酸同源性为100.O%,RVl7、RV23代次病毒与D50673的核苷酸序列同源性分别为99.9%、99.7%,氨基酸序列同源性分别为99.8%、99.2%.各代次病毒与糖基化、抗原性相关的氨基酸位点未发生变异,高度保守;风疹病毒Matsuba株与其他参考株E1基因序列比较结果表明:Matsuba株为1a基因型,中国风疹病毒流行基因型为1E、1F、2A和2B,以1E基因型为主;Matsuba株与各基因型参考株同源性很高,核苷酸和氨基酸同源性分别为92.1%～99.6%和98.1%～99.8%. 结论 风疹病毒Matsuba疫苗株的遗传学特性稳定,从分子水平证明Matsuba疫苗株及其生产的疫苗具有安全性.尽管中国流行不同基因型风疹病毒,由于Matsuba株与各基因型参考株同源性很高,且风疹病毒毒株间抗原表位高度保守,因此Matsuba疫苗株所生产的疫苗可以有效保护不同基因型别的风疹病毒的感染.

Study oil the heredity and variance of E1 gene of rubella virus Matsuba strain

Objecflve To study the heredity and variance of E1 gene of rubella villls Matsuba vac-cine strain.and to evaluate the protective efficacy of the vaccine prepared by Matsuba vaccine strain on genelevel.Methods The Matsuba strain was passaged on primary rabbit kidnev cells from 14 to 23 generations.and the E1 genes of 14,16,17,18,23 passages amplified by RT-PCR were cloned into the T-A cloning vector pGEM-T and sequenced,respectively.The sequences of E1 gene of the passaged viruses were tom-pared with rubella virus Matsuba reference strain E1 gene(Accession No.D50673)and other rubella strains in GenBank.respectively.Results The Matanba passaged shared higher homology of nucleotide and amino acid with Matsuba reference strain(D50673).,The sequences of nucleotide and amino acid of RV14,RV16.RV18 were identical to D50673.The homology of nucleotide sequences of RV17,RV23 and D50673 was 99.9%and 99.7%,respectively,andthe homology of amino acidwgg 99.8% and 99.2%,respective-ly.The amino acid related to glycosylation and epitopes of the passage viruses were highly conservative.The phylogenetic tree showed Matsuba strain belonged to la genotype.The rubella virus genotypes circulated in China recent years were 1E,lF,2A and 2B,and 1E genotype was the predominant genotype.The homology of nucleotide and amino acid of Matsuba strain and the other genotype reference strains was 92.1%-99.6% and 98.1%-99.8%.respectively.Condusion The Matsuba vaccine strain possesses highly genetic stabil-ity.which indicates that the Matsuba strain and its vaccine are stable on molecular level.And the vaccine prepared by Matsuba vaccine strain can prevent the infection of various genotype rubella viruses.