Guangdong Laboratory for Lingnan Modern Agriculture, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Institute of Animal Husbandry and Veterinary Medicine, Fujian Academy of Agricultural Sciences, Fuzhou, China.
J Virol. 2023 Feb 28;97(2):e0194722. doi: 10.1128/jvi.01947-22. Epub 2023 Jan 19.
Members of deltacoronavirus (DCoV) have mostly been identified in diverse avian species as natural reservoirs, though the porcine DCoV (PDCoV) is a major swine enteropathogenic virus with global spread. The important role of aminopeptidase N (APN) orthologues from various mammalian and avian species in PDCoV cellular entry and interspecies transmission has been revealed recently. In this study, comparative analysis indicated that three avian DCoVs, bulbul DCoV HKU11, munia DCoV HKU13, and sparrow DCoV HKU17 (Chinese strain), and PDCoV in the subgenera are grouped together at whole-genome levels; however, the spike (S) glycoprotein and its S1 subunit of HKU17 are more closely related to night heron DCoV HKU19 in . Nevertheless, the S1 protein of HKU11, HKU13, or HKU17 bound to or interacted with chicken APN (chAPN) or porcine APN (pAPN) by flow cytometry analysis of cell surface expression of APN and by coimmunoprecipitation in APN-overexpressing cells. Expression of chAPN or pAPN allowed entry of pseudotyped lentiviruses with the S proteins from HKU11, HKU13 and HKU17 into nonsusceptible cells and natural avian and porcine cells, which could be inhibited by the antibody against APN or anti-PDCoV-S1. APN knockdown by siRNA or knockout by CRISPR/Cas9 in chicken or swine cell lines significantly or almost completely blocked infection of these pseudoviruses. Hence, we demonstrate that HKU11, HKU13, and HKU17 with divergent S genes likely engage chAPN or pAPN to enter the cells, suggesting a potential interspecies transmission from wild birds to poultry and from birds to mammals by certain avian DCoVs. The receptor usage of avian deltacoronaviruses (DCoVs) has not been investigated thus far, though porcine deltacoronavirus (PDCoV) has been shown to utilize aminopeptidase N (APN) as a cell receptor. We report here that chicken or porcine APN also mediates cellular entry by three avian DCoV (HKU11, HKU13, and HKU17) spike pseudoviruses, and the S1 subunit of three avian DCoVs binds to APN and in the surface of avian and porcine cells. The results fill the gaps in knowledge about the avian DCoV receptor and elucidate important insights for the monitoring and prevention of potential interspecies transmission of certain avian DCoVs. In view of the diversity of DCoVs, whether this coronavirus genus will cause novel virus to emerge in other mammals from birds, are worthy of further surveillance and investigation.
德尔塔冠状病毒（DCoV）的成员主要在不同的禽类物种中被鉴定为天然宿主，尽管猪德尔塔冠状病毒（PDCoV）是一种具有全球传播能力的主要猪肠道致病性病毒。最近揭示了各种哺乳动物和禽类的氨肽酶 N（APN）同源物在 PDCoV 细胞进入和种间传播中的重要作用。在这项研究中，比较分析表明，三种禽 DCoV，即八哥 DCoV HKU11、文鸟 DCoV HKU13 和麻雀 DCoV HKU17（中国株），以及亚属中的 PDCoV，在全基因组水平上聚集在一起；然而，HKU17 的刺突（S）糖蛋白及其 S1 亚基与夜鹭 DCoV HKU19 更为密切相关。然而，通过流式细胞术分析 APN 表面表达和在 APN 过表达细胞中的共免疫沉淀，HKU11、HKU13 或 HKU17 的 S1 蛋白与鸡 APN（chAPN）或猪 APN（pAPN）结合或相互作用。表达 chAPN 或 pAPN 允许带有 S 蛋白的假型慢病毒进入非易感细胞以及天然禽和猪细胞，而针对 APN 或抗 PDCoV-S1 的抗体可以抑制这种进入。在鸡或猪细胞系中通过 siRNA 敲低或通过 CRISPR/Cas9 敲除 APN，可显著或几乎完全阻止这些假病毒的感染。因此，我们证明了具有不同 S 基因的 HKU11、HKU13 和 HKU17 可能通过 chAPN 或 pAPN 进入细胞，这表明某些禽 DCoV 可能通过野生鸟类向家禽以及从鸟类向哺乳动物传播。目前尚未研究禽德尔塔冠状病毒（DCoV）的受体使用情况，尽管已表明猪德尔塔冠状病毒（PDCoV）利用氨肽酶 N（APN）作为细胞受体。我们在此报告，鸡或猪 APN 也介导三种禽 DCoV（HKU11、HKU13 和 HKU17）刺突假病毒的细胞进入，并且三种禽 DCoV 的 S1 亚基与 APN 结合并位于禽和猪细胞的表面。该结果填补了禽 DCoV 受体知识方面的空白，并为监测和预防某些禽 DCoV 的潜在种间传播提供了重要的见解。鉴于 DCoV 的多样性，这种冠状病毒属是否会导致新型病毒从鸟类传播到其他哺乳动物，值得进一步监测和调查。
