Figure 3.

SP-A inhibits entry of SARS-CoV-2 pseudotyped lentiviral particles in susceptible host cells. We measured the luciferase intensity of the SP-A (0-50 μg/ml) pre-treated WT S protein pseudotyped lentiviral particles in the cell lines: (A) HEK293T-ACE2+TMPRSS2; (B) A549-ACE2. (C) Representative images of GFP-positive cells in HEK293T-ACE2+TMPRSS2 challenged with SP-A pre-treated and un-treated GFP-tagged SARS-CoV-2 pseudotyped particles. (D) GFP signal taken from 10 images per well, normalized to the cellular area and quantified by Image J software. The data were expressed as mean ± SEM of the percentage of positive cells/total cells per area analyzed (n=3). Scale bar = 100 μm. *P<0.05; **P<0.01, compared to control sample (0 μg/ml). #<0.05, ##<0.01, compared between two SP-A doses. ns = not significant.