O型口蹄疫病毒衣壳蛋白在昆虫细胞中的表达

Expression of capsid proteins of serotype O foot-and-mouth disease virus in insect cells

为构建表达O型口蹄疫病毒(FMDV)衣壳蛋白的重组杆状病毒,本研究将FMDV O/YS/CHA/05株的P12A和3C基因克隆于pFastBac1载体中,构建重组转移质粒pFast-P12A3C,将其转化DH10Bac感受态细胞,获得重组杆粒rBacmid-P12A3C。将该重组杆粒转染Sf9昆虫细胞,制备重组杆状病毒rBV-P12A3C。间接免疫荧光试验(IFA)检测表明,获得的重组杆状病毒在Sf9细胞中能够表达O型FMDV衣壳蛋白。Western blot分析显示,FMDV的衣壳蛋白和3C蛋白酶均获得表达,并且3C蛋白酶对结构蛋白进行了正确切割。重组蛋白表达的动力学分析显示,表达的FMDV衣壳蛋白具有良好的反应原性,并且在重组杆状病毒感染Sf9细胞后第4 d蛋白表达量达到最大。该重组杆状病毒的构建,为研究FMDV空衣壳的体外组装以及O型FMDV空衣壳疫苗的开发建立了实验基础。

To construct the recombinant baculovirus expressing capsid proteins of serotype O foot-and-mouth disease virus （FMDV）, a fusion gene of P1-2A and 3C of FMDV O/YS/CHA/05 strain was expressed from the constructed recombinant baculovirus rBV-P12A3C in Sf9 cells detected by indirect immunefluorescence assay. Western blot analyses showed that the expressed capsid protein was correctly cleavage by 3C proteinase. In addition, expression kinetics analysis showed that the expressed FMDV capsid proteins possessed good reactogenicity and the maximal expression of the capsid proteins in Sf9 cells occurred at the 4th day post infection with the recombinant baculovirus. The construction of the recombinant baculovirus would help to study the assembly of FMDV empty capsids in vitro and develop the serotype O FMDV empty capsid vaccine.