Fig. 3.

Susceptibility of primary murine alveolar epithelial cells to infection by mouse-adapted SARS-CoV. (A) Murine cells were cultured as either an ATI or ATII cell phenotype for 5 days, then were inoculated with mouse-adapted SARS-CoV, isolate v2163 for 24 or 48 h. Infection was analyzed by immunofluorescence assay of viral nucleocapsid protein (red) and nuclei were stained with DAPI (blue). (B) Cells cultured for 5 days with an ATI cell phenotype were analyzed by immunofluorescence using rabbit antibodies against ACE2 or TMPRSS2 (green) and nuclei were stained with DAPI (blue). A fluorescently labeled antibody against rabbit IgG was used as a negative control.