Infectious Clones Produce SARS-CoV-2 That Causes Severe Pulmonary Disease in Infected K18-Human ACE2 Mice.

Newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic, which has caused extensive mortality and morbidity and wreaked havoc on socioeconomic structures. The urgent need to better understand SARS-CoV-2 biology and enable continued development of effective countermeasures is aided by the production of laboratory tools that facilitate SARS-CoV-2 research. We previously created a directly accessible SARS-CoV-2 toolkit containing user-friendly reverse genetic (RG) infectious clones of SARS-CoV-2. Here, using K18-human ACE2 (hACE2) mice, we confirmed the validity of RG-rescued SARS-CoV-2 viruses to reproduce the infection profile, clinical disease, and pathogenesis already established in mice infected with natural SARS-CoV-2 isolates, often patient derived. RG-rescued SARS-CoV-2-infected K18-hACE2 mice developed substantial clinical disease and weight loss by day 6 postinfection. RG-rescued SARS-CoV-2 was recovered from the lungs and brains of infected K18-hACE2 mice, and infection resulted in viral pneumonia with considerable changes in lung pathology, as seen previously with natural SARS-CoV-2 infection. In mice infected with RG-rescued SARS-CoV-2-mCherry, mCherry was detected in areas of lung consolidation and colocalized with clinically relevant SARS-CoV-2-assocated immunopathology. RG-rescued SARS-CoV-2 viruses successfully recapitulated many of the features of severe COVID-19 associated with the K18-hACE2 model of SARS-CoV-2 infection. With utility in vivo, the RG-rescued SARS-CoV-2 viruses will be valuable resources to advance numerous areas of SARS-CoV-2 basic research and COVID-19 vaccine development.IMPORTANCE To develop COVID-19 countermeasures, powerful research tools are essential. We produced a SARS-COV-2 reverse genetic (RG) infectious clone toolkit that will benefit a variety of investigations. In this study, we further prove the toolkit's value by demonstrating the in vivo utility of RG-rescued SARS-CoV-2 isolates. RG-rescued SARS-CoV-2 isolates reproduce disease signs and pathology characteristic of the K18-hACE2 mouse model of severe COVID-19 in infected mice. Having been validated as a model of severe COVID-19 previously using only natural SARS-CoV-2 isolated from patients, this is the first investigation of RG-rescued SARS-CoV-2 viruses in K18-hACE2 mice. The RG-rescued SARS-CoV-2 viruses will facilitate basic understanding of SARS-CoV-2 and the preclinical development of COVID-19 therapeutics.

Liu X ，Zaid A ，Freitas JR ，McMillan NA ，Mahalingam S ，Taylor A ... -  《mBio》

SARS-CoV-2 Causes Lung Infection without Severe Disease in Human ACE2 Knock-In Mice.

Winkler ES ，Chen RE ，Alam F ，Yildiz S ，Case JB ，Uccellini MB ，Holtzman MJ ，Garcia-Sastre A ，Schotsaert M ，Diamond MS ... -  《-》

The K18-Human ACE2 Transgenic Mouse Model Recapitulates Non-severe and Severe COVID-19 in Response to an Infectious Dose of the SARS-CoV-2 Virus.

Dong W ，Mead H ，Tian L ，Park JG ，Garcia JI ，Jaramillo S ，Barr T ，Kollath DS ，Coyne VK ，Stone NE ，Jones A ，Zhang J ，Li A ，Wang LS ，Milanes-Yearsley M ，Torrelles JB ，Martinez-Sobrido L ，Keim PS ，Barker BM ，Caligiuri MA ，Yu J ... -  《-》

Mouse-Adapted SARS-CoV-2 MA10 Strain Displays Differential Pulmonary Tropism and Accelerated Viral Replication, Neurodissemination, and Pulmonary Host Responses in K18-hACE2 Mice.

Thieulent CJ ，Dittmar W ，Balasuriya UBR ，Crossland NA ，Wen X ，Richt JA ，Carossino M ... -  《mSphere》

Human convalescent plasma protects K18-hACE2 mice against severe respiratory disease.

Golden JW ，Zeng X ，Cline CR ，Garrison AR ，White LE ，Fitzpatrick CJ ，Kwilas SA ，Bowling PA ，Fiallos JO ，Moore JL ，Sifford WB ，Ricks KM ，Mucker EM ，Smith JM ，Hooper JW ... -  《-》