Fig. 3: α₁AT inhibits SARS-CoV-2 infection and replication.

a TMPRSS2-expressing Vero E6 cells were treated with Prolastin (α₁AT), EK1 or camostat mesylate (CM) for 1 h, and infected with SARS-CoV-2 isolates either from France (gray) or the Netherlands (blue) at a MOI of 0.001. Virus-induced cytopathic effects were assessed at 2 days post infection by MTS assay (see Supplementary Fig. 4 a, b for raw and cell viability data). b TMPRSS2-expressing Vero E6 cells were treated with Prolastin (α₁AT) at indicated timepoints prior to, simultaneously with or post infection with SARS-CoV-2 at a MOI of 0.001. Camostat mesylate (CM) control was added 1 h prior to infection. Infection rates were assessed at 2 days post infection by MTS assay (see also Supplementary Fig. 5a, b for raw and cell viability data). c TMPRSS2-expressing Vero E6 cells were treated with Prolastin (α₁AT) or CM 1 h prior to, simultaneously with or 1.5 h post infection with SARS-CoV-2. At 1.5 h post infection cellulose overlay was performed. At 2 days post infection, cells were stained with crystal violet (see Supplementary Fig. 6a, b) and plaque areas were quantified. The mean ± SEM from n = 1 (a, EK1 and CM) or n = 2 independent experiments in biological triplicates (a, α₁AT, b) or duplicates (c) and quadruplicates (c, infected) are shown. (2-way ANOVA with Dunett´s multiple comparison test (a, b), ordinary one-way ANOVA with Dunett´s multiple comparison test (c)). Source data are provided as a Source data file.