FIG 8.

Partial inhibition of infectivity by combined TMPRSS2 and cathepsin inhibitors in U2OS cells. The TMPRSS2 inhibitor camostat and the cathepsin inhibitor E64D were evaluated for their capacity to block PV infectivity, alone or in combination. The percent infectivity inhibition was measured by the mean decrease in luciferase activity for 3 independent experiments, with 2 technical replicates per experiment: [1 − (RLU treated/RLU untreated)] × 100. The percent infectivity inhibition is reported in radar plots for camostat (blue line), E64D (green line), or the combination of the two inhibitors (red line) in HEK-ACE2 (A), HEK-ACE2-TMPRSS2 (B), Calu-3 (C), U2OS-ACE2 (D), and U2OS-ACE2-TMPRSS2 (E) cells. The names of PV carrying the D614G mutation are in red.