CCR2 signaling restricts SARS-CoV-2 infection

Using mouse-adapted SARS-CoV-2 and B.1.351 variant infection model, it was demonstrated that an inflammatory response in the lung characterized by the expression of pro-inflammatory cytokines and interferon-stimulatied genes was prominent in the infected mice. The mouse adapted virus infection led to the increase of circulating monocytes and CD45+ cells infiltrating into the lung parenchyma. Single cell RNA seq revealed that these monocytes were hyperinflammatory. Using CCR2 knockout mice, it was shown that CCR2 is important for the infiltration of these cells and reducing of viral burden.