Figure 2.
Inhibitors 1, 2 and remdesivir potently blocked the infectivity and cytopathic effect of SARS-CoV-2WK-521 in VeroE6 cells. VeroE6 cells were exposed to SARS-CoV-2WK-521 at an MOI of 0.05 and cultured in the presence or absence of test compounds. After 3 days, the cells were fixed with 4% paraformaldehyde and immunocytochemistry was conducted using the IgG fraction from serum of a COVID-19-convalescent patient, who had high-titer SARS-CoV-2-binding IgG,44 and a green fluorescence-conjugated goat polyclonal anti-human-IgG-Alexa Fluor 488 Fab fragment as the primary and secondary antibodies, respectively. SARS-CoV-2 antigens, filamentous actin, and nuclei are shown in green, red, and blue, respectively.