Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture; Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing 210014, China; College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
Institute of Pathogenic Microorganism, Jiangxi Agricultural University, Nanchang 330045, China.
Vet Microbiol. 2024 Oct;297:110211. doi: 10.1016/j.vetmic.2024.110211. Epub 2024 Jul 31.
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.
猪德尔塔冠状病毒（PDCoV）是一种跨种传播的肠道病毒，常引起仔猪严重腹泻和呕吐症状，不仅对全球养猪业构成重大威胁，也对公共安全构成潜在风险。在之前的研究中，我们通过在体外传代一种亲本 PDCoV 株分离出候选疫苗 PDCoV CZ2020-P100，该候选疫苗具有较弱的毒力和增强的复制能力。然而，这些原代和传代株之间差异的背后的因素仍不清楚。在这项研究中，我们使用 RNA-seq 技术研究了 PDCoV CZ2020-P1 株和 P100 株感染猪肾上皮细胞（LLC-PK1）后的转录组。我们发现 P1 感染细胞中有 105 个差异表达基因（DEGs），P100 感染细胞中有 295 个 DEGs。富集分析表明，许多 DEGs 参与了免疫和炎症反应，P100 感染组中更多和更高水平的 DEGs 被富集。值得注意的是，DEGs 在 P100 感染组中集中在 MAPK 通路中，EphA2 和 c-Fos 显著上调。与 P1 相比，EphA2 和 c-Fos 的敲低降低了 PDCoV 感染并显著抑制了 P100 的复制，表明 EphA2 和 c-Fos 高度参与了传代病毒的复制。我们的研究结果阐明了感染 P1 和 P100 的宿主细胞基因表达谱的相似性和差异，证实了 EphA2 和 c-Fos 在高传代 PDCoV 复制中起着关键作用。这些结果提高了我们对传代过程中毒力和复制能力变化的认识。
