Broad Cross-Species Infection of Cultured Cells by Bat HKU2-Related Swine Acute Diarrhea Syndrome Coronavirus and Identification of Its Replication in Murine Dendritic Cells In Vivo Highlight Its Potential for Diverse Interspecies Transmission
Broad Cross-Species Infection of Cultured Cells by Bat HKU2-Related Swine Acute Diarrhea Syndrome Coronavirus and Identification of Its Replication in Murine Dendritic Cells In Vivo Highlight Its Potential for Diverse Interspecies Transmission
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蝙蝠 HKU2 相关猪急性腹泻综合症冠状病毒对培养细胞的广泛跨物种感染及其在小鼠树突状细胞体内复制的鉴定突显了其多种跨物种传播的潜力
DOI：
10.1128/jvi.01448-19
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发表时间：
2019-12-01
影响因子：
5.4
通讯作者：
Huang, Yao-Wei
中科院分区：
文献类型：
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作者：
Yang, Yong-Le;Qin, Pan;Huang, Yao-Wei
2017年，中国广东的新生仔猪暴发严重腹泻，由此分离并发现了一种新型猪肠道甲型冠状病毒（SeACoV），该病毒源自菊头蝠冠状病毒HKU2（潘阳，田雪，秦鹏，王博等，《兽医微生物学》211卷：15 - 21页，2017年）。随后，另一研究团队将SeACoV称为猪急性腹泻综合征冠状病毒（SADS - CoV）（周鹏，范浩，兰天，杨晓丽等，《自然》556卷：255 - 258页，2018年）。本研究旨在从体外和体内探究SADS - CoV潜在的种属屏障。我们首先证明，SADS - CoV具有广泛的种属嗜性，能够感染来自多种物种的细胞系，包括蝙蝠、小鼠、大鼠、沙鼠、仓鼠、猪、鸡、非人灵长类动物以及人类。胰蛋白酶有助于SADS - CoV在体外的增殖，但并非必不可少。此外，通过口服或腹腔注射途径给C57BL / 6J小鼠接种该病毒。尽管小鼠仅表现出亚临床感染，但它们支持病毒在脾脏中的复制并延长感染时间。在淋巴滤泡边缘的边缘区脾细胞中检测到SADS - CoV非结构蛋白和双链RNA，这表明SADS - CoV在小鼠模型中活跃复制。我们通过免疫荧光和流式细胞术方法确定，脾脏树突状细胞（DCs）是病毒感染的主要靶细胞。最后，我们证明SADS - CoV进入细胞不依赖已知的冠状病毒受体。SADS - CoV在多种物种的不同细胞系中复制的能力以及对小鼠树突状细胞出人意料的嗜性，为深入了解这种源自蝙蝠的冠状病毒的生物学特性提供了重要线索，凸显了其跨越种属屏障的潜在能力。
重要意义：源自蝙蝠的冠状病毒（如严重急性呼吸综合征冠状病毒[SARS - CoV]和中东呼吸综合征冠状病毒[MERS - CoV]）在发生“宿主跳跃”事件后，已导致人类严重疾病。最近，一种类似蝙蝠HKU2的新型冠状病毒——猪急性腹泻综合征冠状病毒（SADS - CoV）在中国南方出现，导致新生仔猪致命性腹泻。鉴于除猪和蝙蝠外，SADS - CoV的动物宿主及人畜共患潜力仍不明确，评估其感染的种属屏障至关重要。一项体外易感性研究揭示了SADS - CoV广泛的种属嗜性，包括多种啮齿动物和人类细胞系。我们建立了SADS - CoV感染的小鼠模型，确定其在脾脏树突状细胞中活跃复制，这表明SADS - CoV具有感染啮齿动物的潜力。这些发现凸显了SADS - CoV潜在的跨物种传播能力，尽管还需要对其他动物种群进行进一步监测，以全面了解这种源自蝙蝠HKU2的冠状病毒的生态学特性。
Outbreaks of severe diarrhea in neonatal piglets in Guangdong, China, in 2017 resulted in the isolation and discovery of a novel swine enteric alphacoronavirus (SeACoV) derived from the species Rhinolophus bat coronavirus HKU2 (Y. Pan, X. Tian, P. Qin, B. Wang, et al., Vet Microbiol 211:15-21, 2017). SeACoV was later referred to as swine acute diarrhea syndrome CoV (SADS-CoV) by another group (P. Zhou, H. Fan, T. Lan, X.-L. Yang, et al., Nature 556:255-258, 2018). The present study was set up to investigate the potential species barriers of SADS-CoV in vitro and in vivo. We first demonstrated that SADS-CoV possesses a broad species tropism and is able to infect cell lines from diverse species, including bats, mice, rats, gerbils, hamsters, pigs, chickens, nonhuman primates, and humans. Trypsin contributes to but is not essential for SADS-CoV propagation in vitro. Furthermore, C57BL/6J mice were inoculated with the virus via oral or intraperitoneal routes. Although the mice exhibited only subclinical infection, they supported viral replication and prolonged infection in the spleen. SADS-CoV nonstructural proteins and double-stranded RNA were detected in splenocytes of the marginal zone on the edge of lymphatic follicles, indicating active replication of SADS-CoV in the mouse model. We identified that splenic dendritic cells (DCs) are the major targets of virus infection by immunofluorescence and flow cytometry approaches. Finally, we demonstrated that SADS-CoV does not utilize known CoV receptors for cellular entry. The ability of SADS-CoV to replicate in various cells lines from a broad range of species and the unexpected tropism for murine DCs provide important insights into the biology of this bat-origin CoV, highlighting its possible ability to cross interspecies barriers.IMPORTANCE Infections with bat-origin coronaviruses (CoVs) (severe acute respiratory syndrome CoV [SARS-CoV] and Middle East respiratory syndrome CoV [MERS-CoV]) have caused severe illness in humans after "host jump" events. Recently, a novel bat-HKU2-like CoV named swine acute diarrhea syndrome CoV (SADS-CoV) has emerged in southern China, causing lethal diarrhea in newborn piglets. It is important to assess the species barriers of SADS-CoV infection since the animal hosts (other than pigs and bats) and zoonotic potential are still unknown. An in vitro susceptibility study revealed a broad species tropism of SADS-CoV, including various rodent and human cell lines. We established a mouse model of SADS-CoV infection, identifying its active replication in splenic dendritic cells, which suggests that SADS-CoV has the potential to infect rodents. These findings highlight the potential crossspecies transmissibility of SADS-CoV, although further surveillance in other animal populations is needed to fully understand the ecology of this bat-HKU2-origin CoV.