PDF(Pubmed)
Abstract：
Animal models of authentic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection require operation in biosafety level 3 (BSL-3) containment. In the present study, we established a mouse model employing a single-cycle infectious virus replicon particle (VRP) system of SARS-CoV-2 that can be safely handled in BSL-2 laboratories. The VRP [ΔS-VRP(G)-Luc] contains a SARS-CoV-2 genome in which the spike gene was replaced by a firefly luciferase (Fluc) reporter gene (Rep-Luci), and incorporates the vesicular stomatitis virus glycoprotein on the surface. Intranasal inoculation of ΔS-VRP(G)-Luc can successfully transduce the Rep-Luci genome into mouse lungs, initiating self-replication of Rep-Luci and, accordingly, inducing acute lung injury mimicking the authentic SARS-CoV-2 pathology. In addition, the reporter Fluc expression can be monitored using a bioluminescence imaging approach, allowing a rapid and convenient determination of viral replication in ΔS-VRP(G)-Luc-infected mouse lungs. Upon treatment with an approved anti-SARS-CoV-2 drug, VV116, the viral replication in infected mouse lungs was significantly reduced, suggesting that the animal model is feasible for antiviral evaluation. In summary, we have developed a BSL-2-compliant mouse model of SARS-CoV-2 infection, providing an advanced approach to study aspects of the viral pathogenesis, viral-host interactions, as well as the efficacy of antiviral therapeutics in the future.IMPORTANCESevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly contagious and pathogenic in humans; thus, research on authentic SARS-CoV-2 has been restricted to biosafety level 3 (BSL-3) laboratories. However, due to the scarcity of BSL-3 facilities and trained personnel, the participation of a broad scientific community in SARS-CoV-2 research had been greatly limited, hindering the advancement of our understanding on the basic virology as well as the urgently necessitated drug development. Previously, our colleagues Jin et al. had generated a SARS-CoV-2 replicon by replacing the essential spike gene in the viral genome with a Fluc reporter (Rep-Luci), which can be safely operated under BSL-2 conditions. By incorporating the Rep-Luci into viral replicon particles carrying vesicular stomatitis virus glycoprotein on their surface, and via intranasal inoculation, we successfully transduced the Rep-Luci into mouse lungs, developing a mouse model mimicking SARS-CoV-2 infection. Our model can serve as a useful platform for SARS-CoV-2 pathological studies and antiviral evaluation under BSL2 containment.
摘要：
真正的严重急性呼吸道综合症冠状病毒2（SARS-CoV-2）感染的动物模型需要在生物安全3级（BSL-3）密闭条件下进行操作。在本研究中,我们使用SARS-CoV-2的单周期感染性病毒复制子颗粒（VRP）系统建立了小鼠模型，该模型可以在BSL-2实验室中安全处理。VRP[ΔS-VRP（G）-Luc]包含SARS-CoV-2基因组，其中刺突基因被萤火虫荧光素酶（Fluc）报告基因（Rep-Luci）取代，并在表面掺入水泡性口炎病毒糖蛋白。经鼻内接种ΔS-VRP(G)-Luc可成功将Rep-Luci基因组导入小鼠肺,启动Rep-Luci的自我复制，因此,模拟真正的SARS-CoV-2病理诱导急性肺损伤。此外,可以使用生物发光成像方法监测报告子Fluc表达，允许在ΔS-VRP（G）-Luc感染的小鼠肺中快速和方便地确定病毒复制。经批准的抗SARS-CoV-2药物治疗后，VV116，病毒在感染小鼠肺部的复制显著减少，提示该动物模型用于抗病毒评价是可行的。总之,我们开发了符合BSL-2标准的SARS-CoV-2感染小鼠模型，提供一种先进的方法来研究病毒发病机理的各个方面，病毒-宿主相互作用，以及未来抗病毒疗法的疗效。重要急性呼吸道综合症冠状病毒2（SARS-CoV-2）在人类中具有高度传染性和致病性；因此，对真正的SARS-CoV-2的研究仅限于生物安全3级（BSL-3）实验室。然而,由于缺乏BSL-3设施和训练有素的人员，广泛的科学界对SARS-CoV-2研究的参与受到了极大的限制，阻碍了我们对基本病毒学的理解以及迫切需要的药物开发的进步。以前,我们的同事Jin等人。通过用Fluc报告基因（Rep-Luci）替换病毒基因组中的必需刺突基因，产生了SARS-CoV-2复制子，可以在BSL-2条件下安全操作。通过将Rep-Luci掺入表面携带水泡性口炎病毒糖蛋白的病毒复制子颗粒中，通过鼻内接种，我们成功地将Rep-Luci导入小鼠肺,开发模拟SARS-CoV-2感染的小鼠模型。我们的模型可以作为SARS-CoV-2病理学研究和BSL2遏制下抗病毒评估的有用平台。
