Fig. 1

Validation of SARS-CoV-2 S protein pseudotyped reporter viruses for the screening and quantification of antiviral drugs and neutralization antibodies. A A lentiviral particle, SARS-CoV-2(GFP) that was pseudotyped with the SARS-CoV-2 S protein, was used to infect A549(ACE2) target cells. GFP was used as the reporter to quantify viral infection, and was measured at 48 h post infection with flow cytometry. Propidium iodide (PI) was added during flow cytometry to stain for dying and dead cells. Arbidol (10 mM) was tested in the system for blocking viral infection. GFP + cells were quantified only in the viable cell population or in the whole cell population. B An example of using SARS-CoV-2(GFP) to screen for TCMs. Extract from Manchurian Wildginger (2 mg/ml) was used to pretreat cells which were infected in the presence of M. Wildginger. After infection, cells were cultured in the absence of M. Wildginger for 48 h. GFP expression was quantified. C A lentiviral particle, SARS-CoV-2(Luc) pseudotyped with the SARS-CoV-2 S protein, was used to infect A549(ACE2) target cells. Luciferease (Luc) was used as the reporter to quantify viral infection. Luc was measured at 72 h post infection. The SARS-CoV-2 neutralizing antiserum 8F was serially diluted and incubated with viral particles for 1 h. The complex was added to infect cells. Luc expression was quantified at 72 h post infection