Fig. 1

Development of a pseudovirus model of SARS-CoV-2 infection. Infectivity of wild-type (WT), 19del, and 19del + D614G SARS-CoV-2 pseudoviruses. hACE2 expressing 293TT cells were infected with wild-type, 19del, or 19del + D614G SARS-CoV-2 pseudoviruses (quantified as 25ng of HIV Gag p24 protein) for 72 h. Cell lysates were collected and relative luminescence units (RLU) were measured (a). Schematic diagram of in vivo infection protocol (b). 6–8-week-old female BALB/c mice were infected intranasally (i.n.) with a hACE2-expressing adenovirus (2.5 × 10⁸ PFU) (AdV-hACE2). Five days later, mice were challenged with luciferase-expressing pseudoviruses (n = 3 per group) (quantified as 850ng of HIV Gag p24 protein). Mice were imaged on days 1, 4, 8, and 11 after pseudovirus infection. Untreated naïve mice (n = 3) were used as background controls. Representative bioluminescence and kinetics of mouse infection with 19del or 19del + D614G pseudoviruses (c). Quantification of bioluminescence signal in the nasal passage (d) and lungs (collected 13 days post infection) (e). Blocking SARS-CoV-2 PsV infection through RBD treatment. hAEC2-expressing 293TT cells were pre-treated with RBD (1ug/ml) one hour before pseudovirus challenge. Data expressed as mean ± SEM. Student’s t test used to analyze differences between groups. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001