Table 1.
SARS-CoV-2 variants used in ViroSpot reduction and plaque assays to evaluate antiviral properties of stenoparib and remdesivir.
Fig 1.
Dose-response curves for stenoparib and remdesivir on wild type SARS-CoV-2 and four variant SARS-CoV-2 strains.
Normalized percent inhibition (Y-axis) of wt SARS-CoV-2 and variant strains alpha, beta, delta, and gamma in Vero E6 cells treated with (A) stenoparib or (B) remdesivir at the indicated concentrations (X-axis). Error bars are the standard deviation.
Fig 2.
Activity of stenoparib and remdesivir on the alpha SARS-CoV-2 variant and cytotoxicity of stenoparib and remdesivir in Vero E6 cells.
(A) Virus plaque assays. Vero E6 cells were infected for 2 hours with SARS-CoV-2 alpha variant, washed, and overlaid with low-melting temp agarose/MEM with or without stenoparib and/or remdesivir at the concentrations indicated. The cell monolayers were fixed with 4% paraformaldehyde and stained with 0.1% crystal violet prior to manual counting of plaques. The experiment was performed using technical triplicates and error bars represent the standard deviation of three independent experiments. For pairwise comparisons to untreated cells, * indicates p-values less than 0.05 and ** indicates p-values less than 0.01. (B) Photographs of plaque assay plate wells after crystal violet staining. Labels indicate the concentrations of stenoparib or remdesivir. Abbreviations: S = stenoparib, R = remdesivir at the concentrations indicated (i.e. 2.5 / 0.5 = 2.5 μM stenoparib, 0.5 μM remdesivir). (C) Cytotoxicity measurements performed by the lactate dehydrogenase release assay (Promega Cytotox 96) 48 hours after infection. Inhibitors stenoparib or remdesivir were used at the indicated concentrations (X-axis). The assays were performed according to the manufacturer’s recommendations. Results from drug treatments were normalized to the fraction of maximum cytotoxicity (% Cytotoxicity; Y-axis) achieved by detergent lysis of cells. The samples were processed in triplicate and error bars represent the standard deviation of five independent experiments.