Fig. 6

Anti-vimentin antibodies specifically diminished the uptake of SARS-CoV VLPs and spike protein by Vero E6 cells. a The effect of anti-vimentin antibodies and anti-ACE2 antibodies on the uptake of SARS-CoV VLPs. Vero E6 cells were pretreated with rabbit anti-vimentin antibodies RP (RP4002, Immuno Bioscience Corp.) or goat anti-ACE2 antibodies for 30 min prior to the 2-h incubation with SARS-CoV VLPs. The cells were then subjected to flow cytometry analysis for quantitation of the SARS-CoV VLP-positive cells as described in Methods. Rabbit pre-immune serum (PI), and goat IgG as indicated were used as antibody isotype controls in the neutralization experiments. The number of cells pretreated with isotype antibodies was normalized to 100 %, subsequently the relative uptake of SARS-CoV VLPs after antibody neutralization was calculated and shown underneath the bar chart. b The effect of anti-vimentin antibodies on the uptake of spike protein. Vero E6 cells were pretreated with increasing doses of rabbit anti-vimentin antibodies RP (RP4002, Immuno Bioscience Corp.) or mouse anti-vimentin antibodies V (V5255, Sigma) as indicated for 30 min prior to the 2-h incubation with SARS-CoV spike protein. SARS-CoV spike-positive cells were then quantitated by flow cytometry analysis. The number of cells uptake SARS-CoV spike protein after antibody neutralization was calculated and normalized against the number of cells pretreated with IgG control in each set of experiment. * indicates the P value < 0.05