Fig. 5.

Inhibition of SARS-CoV-2 infection by RK-33 and C–4B in Calu-3 cells. A-B) Calu-3 cells were infected with SARS-CoV-2 at MOI 0.001 and, at the end of the adsorption period, were treated with RK-33 or C–4B at the indicated concentrations, or left untreated. At 24 h post infection, cells and supernatants were harvested and assayed for intracellular (A) and extracellular (B) RNA, respectively, by RT-qPCR. The graphs report means ± SD of normalized values from three independent experiments. ** = p < 0.01, *** = p < 0.001. Viral RNA levels are reported as fold changes with respect to the amount detected at 24h post infection. CoV-2: SARS-CoV-2. C) Calu-3 cells were infected with SARS-CoV-2 at MOI 0.001. At the end of the adsorption period, cells were treated with RK-33 or C–4B at the indicated concentrations or left untreated. Supernatants were collected at 24h post infection and subjected to limiting dilution assay on Vero E6 cells. Infectious viral titers are expressed as mean ± SD of Log₁₀TCID50/ml. The graphs report means ± SD of normalized values from three independent experiments. * = p < 0.05, ** = p < 0.01, *** = p < 0.001. NI: non-infected.