动脉炎病毒细胞嗜性蛋白的鉴定

在我们前期研究工作中，根据PRRSV和EAV具有不同细胞嗜性的特性，通过反向遗传操作，将PRRSV的GP2/GP3/GP4编码区替换为EAV相应对的区域，获得嵌合克隆pARRSV-EAV234，对拯救的嵌合病毒vARRSV-EAV234的细胞嗜性进行研究发现,嵌合病毒有着EAV一样广谱地细胞嗜性，但失去对猪肺泡巨噬细胞的感染性，说明GP2/GP3/GP4决定了PRRSV细胞嗜性。在本项目中，我们拟在EAV和PRRSV感染性克隆的基础上，构建两者GP2，GP3或GP4编码区相互替换的嵌合克隆，拯救嵌合病毒，研究嵌合病毒细胞嗜性的变化，进一步确定PRRSV和EAV的细胞嗜性蛋白。最后，构建PRRSV-LDV234嵌合克隆，探讨通过LDV GP2/3/4作为细胞嗜性蛋白来介导PRRSV感染小鼠模型的可行性。本研究将为我们理解动脉炎病毒的入侵机制以及研发抗病毒制剂靶标和优化疫苗设计提供理论依据。

Our previously studies showed that A PRRSV infectious cDNA clone that was equipped with open reading frames (ORFs) encoding minor envelope and E proteins of equine arteritis virus (EAV), the only known arterivirus displaying a broad tropism in cultured cells, was viable. Strikingly, this chimeric virus (vAPRRS-EAV2ab34) acquired the broad in vitro cell tropism of EAV but lost this ability to infect the PAM,demonstrating that the minor envelope proteins play a critical role as viral attachment proteins. In this proposal, we aim to identify the structural proteins responsible for the cell tropism of Arteriviruses. Based on the EAV and PRRSV infectious cDNA clones, a series of chimeric clones, in which the minor envelope protein genes (ORF2, ORF3 or ORF4) of PRRSV are replaced by the corresponding EAV gene set, are constructed. The chimeric viruses are rescued and used to analyse theirs cell tropism. Finally, we construct a chimeric clone in which envelope protein genes of PRRSV were replaced by the corresponding LDV gene set. We then investigate whether the PRRSV/LDV chimeric virus can infect in mice. Our studies will enhance our understanding of arterivirus entry and may be of great significance for the rational design of PRRSV vaccines and antiviral compounds.