Figure 6.

S-RBD meditated cell fusion. Increasing concentrations of SARS-CoV-2 S-RBD fragment were added to either HEK293T or HEK293-ACE2 cells for 0–16 h before epifluorescence microscopy (1 µM RBD and 16 h’ time point in (A) and magnification in (B)). The number of cell fusions observed after incubation with increasing concentration of RBD has been quantified by measuring the number of polynuclei cells (C). the effect of soluble ACE2, Efavirenz and Dolutegravir has been analyzed by adding the protein or drugs simultaneously with the RBD and by quantifying the cell fusion 16 h after treatment (D). Data were obtained from at least two independent experiments and are reported as means ±SD. At least 50 cells have been quantified in each conditions. ** p < 0.05; *** p < 0.001.