FIGURE 3.

HCoV-NL63 S-protein-mediated pseudovirus entry is not affected by cathepsin (Cath) inhibitors. Human ACE2-transfected HEK293T cells were preincubated for 3 h (A, B) or 30 min (C) with infection inhibitors and then incubated with SARS/MLV, NL63/MLV, HIV/MLV, or VSV-G/MLV in the presence of indicated cathepsin inhibitors (A), the broad cysteine protease inhibitor E64d (B), or NH₄Cl, an inhibitor of endosomal acidification (C). Infectivity was assessed as described under”Experimental Procedures.“