Fig. 1

Construction of pseudo-SARS-CoV-2 virus and screening of specific antibodies directed to spike proteins. a Structures of SARS-CoV-2 and the SARS-CoV-2 pseudovirus. b Infectivity of SARS-CoV-2 pseudovirus. HEK-293FT-hACE2 cells transduced with VSV pseudovirus encoding GFP were used as a positive control. c Detection of SARS-CoV-2 S protein incorporated in lentivirus via western blotting. The wild-type spike glycoprotein overexpressed in 293 cells and VSV pseudovirus without spike glycoprotein were used as the positive control and the negative control, respectively. d Detection of target sequence synthesized and cloned in SARS-CoV-2 lentivirus via RT-qPCR using a 2019-nCoV nucleic acid detection kit (Sansure Bio, China). The VSV pseudotype virus was prepared using the same procedure without the target sequence taken as the negative sample. e Identification of potential antibodies binding to the polypeptide fragment of spike glycoproteins via western blot with the lysate of SARS-CoV-2 pseudovirus after heating for 10 min at 100 °C. The SARS-CoV-2 S protein expressed via 293T cells transfected with vector-encoded wild-type SARS-CoV-2 S glycoprotein used as a control. f. Identification of potential antibodies binding to the active Spike glycoproteins of SARS-CoV-2 through the particle gel with pseudovirus resuspension. The VSV pseudotype virus was prepared suing the same procedure and used as a negative control