重组痘病毒表达裂谷热病毒囊膜蛋白及其免疫原性分析

Recombinant vaccinia viruses expressing envelope glycoproteins of rift valley fever virus

裂谷热(Rift valley fever,RVF)是由裂谷热病毒(Rift valley fever virus,RVFV)引起的烈性人畜共患传染病。囊膜糖蛋白G是病毒的主要结构蛋白,由基因组M节段编码,翻译后裂解为Gn和Gc,其中Gn为诱导中和抗体的主要免疫原。本研究分别构建了表达RVFV囊膜蛋白G(n+c)和Gn的重组痘病毒rVV-G (n+c)和rVV-Gn。SDS-PAGE、Western blot结果表明分子量分别为56 Ku(Gn)、58 Ku(Gc)左右的重组蛋白在rVV-G(n+c)和rVV-Gn哺乳动物细胞获得准确表达[G(n+c)裂解为Gn和Gc],并具有特异免疫反应原性。以rBac-G(n+c)和rBac-Gn感染的昆虫细胞裂解物为包被抗原,间接ELISA检测血清抗体结果显示,rVV-G (n+c)和rVV-Gn免疫小鼠可诱导显著的Gn、Gc特异抗体反应,并且rVV-G(n+c)免疫诱导主要保护性免疫原Gn特异抗体反应效果优于rVV-Gn。结果表明,表达全长囊膜糖蛋白重组痘病毒rG(n+c)具有作为安全有效的重组病毒活载体疫苗的潜力,为RVF重组亚单位疫苗的探索研究奠定了基础。

The glycoprotein G （n＋c） of rift valley fever virus is encoded by M segment of the virus genome and subsequently cleaved into two envelope proteins, Gn and Gc. The Gn has been confirmed as most important immunogen to induce protective neutralization antibody. In this study, two recombinant vaccinia viruses, rVV-G （n＋c） and rVV-Gn, were constructed. The expression of Gn and Gc （56 Ku and 58 Ku respectively） in rVV-G （n＋c） or rVV-Gn infected cells was confirmed by SDS-PAGE and Western blot. C,n specific antibodies in mice immunized with rVV-G （n＋c） or rVV-Gn were detected by indirect ELISA using recombinant G （n＋c） or Gn as coating antigens, rVV-G （n＋c） elicited more significant Gn specific antibody response than rVV-Gn. The results indicated that recombinant vaccinia viruses could be used as safe and effective vaccine for the prevention and control of rift valley fever.