弓形虫细胞核因子3基因的克隆及序列分析

Cloning and Sequence Analysis of Toxoplasma gondii NF3 Gene

为预测弓形虫细胞核因子3(TgNF3)基因作为抗弓形虫疫苗候选抗原的可能性,本试验以弓形虫RH株的总RNA为模板,应用逆转录-聚合酶链式反应(RT-PCR)扩增TgNF3基因并连接至pMD18-T载体。筛选阳性克隆后,测序鉴定。将测序结果正确的核苷酸序列翻译成氨基酸序列,运用生物信息学软件分析TgNF3蛋白的结构,预测抗原表位。结果显示,TgNF3基因长约950bp。TgNF3蛋白中包含1个跨膜结构域,9个α-螺旋区,4个β-折叠区,8个亲水区域和10个柔性区域,并预测含有9个线性B细胞抗原表位。结果表明,TgNF3蛋白可能具有良好的免疫原性,为研制以TgNF3为抗原的弓形虫亚单位疫苗及表位疫苗奠定了基础。

In order to predict the possibility of Toxoplasma gondii nuclear factor 3 （TgNF3） as anti-Toxoplasrna gondii vaccine candidate, TgNF3 gene was amplified by one step RT-PCR using a pair of specific primers. Then the fragments were cloned into the pMD18-T vector. The sequence of TgNF3 gene was then translated into amino acids and analyzed by bioinformatics software. The physical and chemical characteristics, hydrophilic domain, transmembrane domain, epitopes, and advanced structure of TgNF3 were predicted by multiple bioinformatics approaches. The results revealed that TgNF3 gene was approximate 950 bp in length. TgNF3 protein was predicted to contain only one transmembrane domain, 9 α-helix regions,4 β-fold regions, 8 hydrophilic regions and 10 flexible regions,and predicted to contain 9 linear B cell epitopes. The results indicated that TgNF3 could be a vaccine candidate antigen against Toxoplasma gondii ,which provided the basic data for development of novel Toxoplasma gondii vaccines.