表达尼帕病毒G囊膜糖蛋白重组牛痘病毒的研究

Generation of recombinant vaccinia virus expressing attachment glycoprotein of Nipah virus

采用牛痘病毒WR株,构建了表达哺乳动物密码子优化的NiV G蛋白基因的重组病毒rWR-NiV-G。Westernblot证实大小为66kDa的重组G蛋白在rWR-NiV-G感染的Hela细胞中获得表达;采用兔抗NiV高免血清间接免疫荧光检测重组痘病毒表达G蛋白显示出良好的特异免疫反应原性。rWR-NiV-G感染NiV敏感的BHK细胞系,并与NiV融合蛋白F共同表达,可形成强烈细胞融合现象。rWR-NiV-G感染免疫BALB/c小鼠,可诱导显著的NiV G蛋白特异体液免疫反应。以原核表达NiV G蛋白片段为包被抗原,间接ELISA检测rWR-NiV-G感染免疫小鼠血清中的G蛋白特异抗体,具有良好的敏感性和特异性。同时,rWR-NiV-G感染免疫小鼠血清中的G蛋白特异抗体可有效中和NiV囊膜蛋白F和G介导的伪型VSV重组病毒侵入NiV易感宿主细胞的感染性。结果表明,重组牛痘病毒表达的NiV G蛋白有良好的免疫原性和生物学活性功能,为进一步深入研究NiV G蛋白生物学功能、免疫原性及重组活载体疫苗研究奠定了重要基础。

The mammalian condon optimized G gene was synthesized by over-lapping PCR and used to generate recombinant vaccinia virus, rWR-NiV-G. The expression of Nipah virus G protein in rWR-NiV-G infected HeLa cells was confirmed by western-blot with NiV G protein specific mouse antiserum generated by DNA immunization.The recombinant G protein showed sensitive and specific antigenic reaction to rabbit serum anti-Nipah virus in indirect florescence. Syncytium formation was induced in BHK cells by rWR-NiVG infection following NiV F protein expressing plasmid pCAGG-NiV-F transfection. Immunization with rWR-NiV-G elicited G protein specific antibody responses in mice. The prokaryotic expressing G protein fragment showed sensitive and specific antigenic reaction to NiV G protein specific antibody from rWR-NiV-G immunized mice serum in indirect ELISA. Furthermore, the G protein specific antibodies could neutralize the infectivity of the recombinant Vesicular Stomatitis Virus pseudotype VSV△G ＊ F/G, in which the VSV envelope protein G gene was replaced with the green fluorescent protein gene （VSV△G ＊ G, Whitt MA） and complemented with Nipah virus F and G glycoprotein expressed in transient （VSV△G＊ F/G）.The results here demonstrated the G protein expressed by rWR-NiV-G keeps native immunogenicity and biological activity. The recombinant virus could be promising vaccine strategy for the prevention of Nipah virus.