Fig. 4.

Effect of other protease inhibitors on SARS-CoV-2 entry. (A) SARS-CoV-2 pseudovirus entry into three types of target cells in the presence of protease inhibitors. For pseudoviruses treated with PPCi, the pseudoviruses were packaged in the presence of PPCi (5 µM) before they were subjected to cell entry. For pseudoviruses treated with TMPRSS2 inhibitor camostat or lysosomal protease inhibitor E64d, pseudovirus entry was performed in the presence of camostat (50 µM) or E64d (50 µM). The cleavage state of SARS-CoV-2 spike was the same as in Fig. 3A (5 µM PPCi condition). The entry efficiency of SARS-CoV-2 pseudoviruses without any treatment was taken as 100%. Error bars indicate SD (n = 4). ***P < 0.001; *P < 0.05. (B) SARS-CoV pseudovirus entry into three types of target cells. The treatments were done in the same way as in A.