Abstract：
Porcine deltacoronavirus (PDCoV), a cross-species transmissible enterovirus, frequently induces severe diarrhea and vomiting symptoms in piglets, which not only pose a significant menace to the global pig industry but also a potential public safety risk. In a previous study, we isolated a vaccine candidate, PDCoV CZ2020-P100, by passaging a parental PDCoV strain in vitro, exhibiting attenuated virulence and enhanced replication. However, the factors underlying these differences between primary and passaged strains remain unknown. In this study, we present the transcriptional landscapes of porcine kidney epithelial cells (LLC-PK1) cells infected with PDCoV CZ2020-P1 strain and P100 strain using the RNA-sequencing. We identified 105 differentially expressed genes (DEGs) in P1-infected cells and 295 DEGs in P100-infected cells. Enrichment analyses indicated that many DEGs showed enrichment in immune and inflammatory responses, with a more and higher upregulation of DEGs enriched in the P100-infected group. Notably, the DEGs were concentrated in the MAPK pathway within the P100-infected group, with significant upregulation in EphA2 and c-Fos. Knockdown of EphA2 and c-Fos reduced PDCoV infection and significantly impaired P100 replication compared to P1, suggesting a novel mechanism in which EphA2 and c-Fos are highly involved in passaged virus replication. Our findings illuminate the resemblances and distinctions in the gene expression patterns of host cells infected with P1 and P100, confirming that EphA2 and c-Fos play key roles in high-passage PDCoV replication. These results enhance our understanding of the changes in virulence and replication capacity during the process of passaging.
摘要：
猪三角洲冠状病毒（PDCoV），跨物种传播的肠道病毒，经常引起仔猪严重的腹泻和呕吐症状，这不仅对全球养猪业构成重大威胁，也是潜在的公共安全风险。在之前的研究中,我们分离出一种候选疫苗,PDCoVCZ2020-P100，通过在体外传代亲本PDCoV菌株，表现出减弱的毒力和增强的复制。然而,主要菌株和传代菌株之间这些差异的潜在因素仍然未知.在这项研究中,我们使用RNA测序呈现了感染PDCoVCZ2020-P1株和P100株的猪肾上皮细胞（LLC-PK1）细胞的转录水平。我们在P1感染的细胞中鉴定了105个差异表达基因（DEGs），在P100感染的细胞中鉴定了295个DEGs。富集分析表明，许多DEGs在免疫和炎症反应中表现出富集，在P100感染组中富含DEGs的上调越来越高。值得注意的是,在P100感染组中，DEGs集中在MAPK途径中，EphA2和c-Fos显著上调。与P1相比，EphA2和c-Fos的敲低可减少PDCoV感染并显着损害P100复制，这表明EphA2和c-Fos高度参与传代病毒复制的新机制。我们的发现阐明了感染P1和P100的宿主细胞的基因表达模式的相似性和区别，证实了EphA2和c-Fos在高传代PDCoV复制中起关键作用。这些结果增强了我们对传代过程中毒力和复制能力变化的理解。
