Antiviral effect of siRNA in vitro
Next, we investigated the antiviral effects of the four selected siRNAs
(siN-3, siN-4, siR-7 and siR-11) in vitro . To evaluate their
antiviral effect, we transfected Vero E6 cells with complexes of
siRNA/Lipofectamine 3000 and four hours after transfection cells were
infected with SARS-CoV-2 at MOI 0.0001. After 48 hours infection cells
were lysed and viral RNA (vRNA) concentration was determined by qRT-PCR.
We found a significant difference in vRNA concentration between cells
treated with specific siR-7, compared to both unspecific
siLuc-transfected and infected cells (P<0.05) (fig.2d). In
addition, a significant reduction of vRNA in cells treated with siN-4
(P<0.05) compared to SARS-CoV-2 infected cells and a trend
towards significance (P=0.0571) to reduce the amount of vRNA compared to
unspecific siLuc-transfected cells were observed. According to these
results the siR-7 targeting SARS-CoV-2 RdRp gene was chosen as best
candidate for further analysis.