Yin Lingdan, Chen Jianfei, Li Liang, Guo Shanshan, Xue Mei, Zhang Jialin, Liu Xiang, Feng Li, Liu Pinghuang
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
J Virol. 2020 Jul 1;94(14). doi: 10.1128/JVI.00480-20.
Porcine deltacoronavirus (PDCoV) is an economically important enteropathogen of swine with worldwide distribution. PDCoV primarily infects the small intestine instead of the large intestine However, the underlying mechanism of PDCoV tropism to different intestinal segments remains poorly understood as a result of the lack of a suitable intestinal model that recapitulates the cellular diversity and complex functions of the gastrointestinal tract. Here, we established the PDCoV infection model of crypt-derived enteroids from different intestinal segments. Enteroids were susceptible to PDCoV, and multiple types of different functional intestinal epithelia were infected by PDCoV and We further found that PDCoV favorably infected the jejunum and ileum and restrictedly replicated in the duodenum and colon. Mechanistically, enteroids from different intestinal regions displayed a distinct gene expression profile, and the differential expression of primary viral receptor host aminopeptidase N (APN) instead of the interferon (IFN) responses determined the susceptibility of different intestinal segments to PDCoV, although PDCoV substantially elicited antiviral genes production in enteroids after infection. Additional studies showed that PDCoV infection significantly induced the expression of type I and III IFNs at the late stage of infection, and exogenous IFN inhibited PDCoV replication in enteroids. Hence, our results provide critical inputs to further dissect the molecular mechanisms of PDCoV-host interactions and pathogenesis. The zoonotic potential of the PDCoV, a coronavirus efficiently infecting cells from a broad range species, including porcine, chicken, and human, emphasizes the urgent need to further study the cell and tissue tropism of PDCoV in its natural host. Herein, we generated crypt stem cell-derived enteroids from porcine different intestinal regions, which well recapitulated the events of PDCoV infection that PDCoV targeted multiple types of intestinal epithelia and preferably infected the jejunum and ileum over the duodenum and colon. Mechanistically, we demonstrated that the expression of APN receptor rather than the IFN responses determined the susceptibility of different regions of the intestines to PDCoV infection, though PDCoV infection markedly elicited the IFN responses. Our findings provide important insights into how the distinct gene expression profiles of the intestinal segments determine the cell and tissue tropism of PDCoV.
猪德尔塔冠状病毒（PDCoV）是一种在全球范围内分布的、对养猪业具有重要经济影响的肠道病原体。PDCoV主要感染小肠而非大肠。然而，由于缺乏一个能够重现胃肠道细胞多样性和复杂功能的合适肠道模型，PDCoV对不同肠段的嗜性潜在机制仍知之甚少。在此，我们建立了来自不同肠段的隐窝源肠类器官的PDCoV感染模型。肠类器官对PDCoV易感，多种不同功能的肠上皮细胞被PDCoV感染。我们进一步发现，PDCoV易于感染空肠和回肠，并在十二指肠和结肠中有限复制。从机制上讲，来自不同肠道区域的肠类器官表现出不同的基因表达谱，虽然PDCoV感染后在肠类器官中大量诱导抗病毒基因的产生，但主要病毒受体宿主氨肽酶N（APN）的差异表达而非干扰素（IFN）反应决定了不同肠段对PDCoV的易感性。额外的研究表明，PDCoV感染在感染后期显著诱导I型和III型IFN的表达，并且外源性IFN抑制肠类器官中PDCoV的复制。因此，我们的结果为进一步剖析PDCoV与宿主相互作用及发病机制的分子机制提供了关键信息。PDCoV这种能有效感染包括猪、鸡和人在内的多种物种细胞的冠状病毒的人畜共患病潜力，凸显了进一步研究PDCoV在其自然宿主中的细胞和组织嗜性的迫切需求。在此，我们从猪的不同肠道区域生成了隐窝干细胞源肠类器官，其很好地重现了PDCoV感染事件，即PDCoV靶向多种类型的肠上皮细胞，并且相较于十二指肠和结肠，更倾向于感染空肠和回肠。从机制上讲，我们证明APN受体的表达而非IFN反应决定了肠道不同区域对PDCoV感染的易感性，尽管PDCoV感染显著引发了IFN反应。我们的研究结果为肠道段独特的基因表达谱如何决定PDCoV的细胞和组织嗜性提供了重要见解。
