RESULTS
G-protein deficient VSV bearing C-terminal 21 aminoacid truncated Spike
protein were packaged in HEK293T cell line (Figure 1 ). To fully
eliminate ancestral VSV-G, Spike pseudoviruses were serially passaged in
pmD2.SpikeCdel21 transfected Vero E6 cells.
Hydroxychloroquine (HCQ) effectively inhibits viral entry and has been
proposed for prophylaxis/treatment of SARS-CoV-2 infection. Therefore,
HCQ was used to display inhibition of pseudovirus entry and construction
of reliable pseudovirus assays. Harvested VSV-ΔG-Sdel21 pseudotyped
virus were analyzed for viral entry using HCQ (20-50 µM). Virus
infectivity was decreased with increasing concentration of
hydroxychloroquine based on percentage of GFP-positive cell(Figure 2A and 2B) . The number of GFP-positive cells in
VSV-ΔG-Sdel21-infected Vero E6 cells were significantly reduced from
30% to 10% in highest concentration of HCQ compared to positive
control (p<0.0001). Representative image of positive control
was given in Figure 2S.