Figure 4.
Fab-IgG 15033-7 and DPP4270-295 synthetic peptide are able to inhibit pseudotype SARS-2-S virus infection. (A) eGFP expression detected by confocal image representative of one alveolosphere infected by VSVpp.SARS-2-S virus (S+). When alveolospheres were treated with antibody neutralizing Fab-IgG 15033-7, eGFP expression is not observed, while when treated with peptide DPP4270–295, the eGFP expression is much lower than that shown with pseudoviruses alone. Scale bar 20 µm. (B) Percentage of eGFP positive alveolospheres, 48 h post infection (hpi) with VSVpp.SARS-2-S WT protein and D614G, Alpha (B.1.1.7 lineage), Beta (B.1.351 lineage), Gamma (P.1 lineage) variants and treated with neutralizing antibody Fab-IgG 15033-7. n = 25–30 fields from three biological replicates and two different observers, * p < 0.05, ** p < 0.01, and *** p < 0.001 by one-way ANOVA test. (C) Transduction efficiency was quantified by measuring virus-encoded luciferase activity in cell infected for 48 h with pseudotypes SARS-2-S WT or variants alone and in combination with Fab-IgG 15033-7. Data are expressed as the percentage of infection and the average data from three biological replicates is presented. Error bars indicate the standard deviation (±SD). *** p < 0.001 by one-way ANOVA test. (D) Percentage of eGFP positive alveospheres 48 hpi with VSVpp.SARS-2-S WT protein and its variants and treated with synthetic peptide DPP4270–295. Two different observers analyzed 25-30 fields from three biological replicates; * p < 0.05 and ** p < 0.01 by one-way ANOVA test. (E) Transduction efficiency was quantified by measuring virus-encoded luciferase activity in cell infected for 48 h with pseudotype SARS-2-S WT or variants alone and in combination with synthetic peptide DPP4270–295. Data are expressed as percentage of infection and the average data from three biological replicates is presented. Error bars indicate the standard deviation (±SD). *** p < 0.001 by one-way ANOVA test.