TABLE 1

Key features of mouse models used in studies of coronavirus infections

Mouse lineDisease modelKey findings[Ref.]
WildtypeSARSSARS-CoV infections resulted into shedding of large amounts of infectious virus with the development of lung injury due to lowering of ACE2 expression[64]
SARSSARS-CoV-infected C3−/− mice exhibited significantly less weight loss and less respiratory dysfunction with reduced lung pathology and lower cytokine and chemokine levels in both the lungs and the sera[65]
Ace2−/−SARSSARS-CoV infections resulted in less shedding infectious virus with mild lung pathological changes due to reduced amount of spike RNA[64]
ARDS/SARSACE2 blockade in mice resulted into enhanced vascular permeability, increased lung oedema, neutrophil accumulation, and worsened lung function[53, 64]
Tmprss2−/−SARSSARS-CoV infection in Tmprss2−/− mice showed attenuated inflammatory chemokine and/or cytokine responses[33]
COVID-19Transcriptional downregulation of Tmprss2 inhibits host SARS-CoV-2 entry.[63]
Tmprss2−/− hDPP4-TgMERSTmprss2−/− murine models infected by MERS-CoV showed improved immunopathology[33]
hACE2COVID-19Mouse model of COVID-19 showing similar pattern of human interstitial pneumonia with infiltration of significant macrophages and lymphocytes into the alveolar interstitium, and accumulation of macrophages in alveolar cavities following SARS-CoV-2 infection[6, 7, 66]
hACE2COVID-19This model developed productive SARS-CoV-2 infection and inflammatory pulmonary infiltrates as seen in COVID-19 patients
Evidence of inadequate antiviral activity and potential harms of endogenous type I IFN responses were observed
[5]
C3−/−SARSSARS-CoV-infected C3−/− mice exhibited significantly less weight loss and less respiratory dysfunction with reduced lung pathology and lower cytokine and chemokine levels in both the lungs and the sera[65]

Ace2−/−: angiotensinogen converting enzyme 2 knockout; SARS: severe acute respiratory syndrome; CoV: coronavirus; C3−/−: complement 3 knockout; ARDS: acute respiratory distress syndrome; Tmprss2−/−: transmembrane protease, serine 2 knockout; COVID-19: coronavirus disease 2019; hDPP4-Tg: human dipeptidyl peptidase 4 transgene; MERS: Middle East Respiratory Syndrome; hACE-2: transgenic mice bearing human ACE2; IFN: interferon.