FIG 4.

SARS-CoV-2 RBD binding and viral infectivity with different ACE2 orthologs. (A) HRT-18G (shaded histogram), HRT-18G/hACE2 (blue trace), HRT-18G/fACE2 (orange trace), and HRT-18G/mACE2 (purple trace) cell lines were incubated with 7.8 ng of the Alexa Fluor 647-labeled SARS-CoV-2 S-protein RBD and analyzed for SARS-CoV-2 S-protein RBD/ACE2 binding by flow cytometry. (B) Same as panel A except that cells were incubated with different concentrations of the Alexa Fluor 647-labeled RBD. The MFI of the population is reported on the y axis. (C) HRT-18G/hACE2, HRT-18G/fACE2, HRT-18G/mACE2, and HRT-18G cells were infected with GFP-expressing SARS-CoV-2 pseudovirus for the specified times, washed to remove excess virus, and incubated for 16 h, and GFP-expressing cells were quantified by flow cytometry. All data presented are representative of results from three independent biological experiments.