Fig 1: Virological features of BA.2(A) 293T cells were transfected with ACE2 or co-transfected with ACE2 and TMPRSS2, followed by transduction with pseudoviruses expressing the spike of SARS-CoV-2 WT, Delta, BA.1, or BA.2 at 24 h post transfection. Pseudovirus entry was quantified by measuring the luciferase signal (n = 6). Fold change in the luciferase signal was normalized to the mean luciferase readouts of cells with only ACE2 overexpression.(B) VeroE6 and VeroE6-TMPRSS2 cells were transduced with pseudoviruses expressing the spike of WT, Delta, BA.1, or BA.2. Pseudovirus entry was quantified by measuring the luciferase signal (n = 8). Fold change in the luciferase signal was normalized to the mean luciferase readouts of VeroE6 cells.(C) VeroE6-TMPRSS2 cells were pre-treated with 1, 25, or 50 µM camostat or DMSO for 2 h, followed by transduction with pseudoviruses expressing the spike of WT, Delta, BA.1, or BA.2 in the presence of camostat. Pseudovirus entry was quantified by measuring the luciferase signal of the cell lysates at 24 h post transduction (n = 6).(D–G) Calu3 and Caco2 cells were pre-treated with 1, 25, or 50 µM camostat (D and F), E64D (E and G), or DMSO (D–G) for 2 h, followed by challenging the cells with authentic WT, Delta, BA.1, or BA.2. The amount of viral sgE RNA in the harvested cell lysates at 24 hpi was determined by qRT-PCR (n = 6).(H) VeroE6-TMPRSS2 cells were infected with the WT, Delta, BA.1, or BA.2 and fixed with 4% paraformaldehyde at the designated time points, followed by crystal violet staining. Plaque diameters were measured by Adobe Photoshop. Plaque diameters for the WT and Delta at 5 dpi were too large to be measured.See also Figures S1 and S2. Data represent mean ± SD from the indicated number of biological repeats. Statistical significance was determined with two way-ANOVA. Data were obtained from three independent experiments. Each data point represents one biological repeat. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. ND, not determined.