Fig. 2.

SARS-CoV-2 3CL inhibits IFN-β, ISRE, and NF-κB promoter activity. (A-C) Luciferase activity of lysates from 293T cells transfected with IFN-β-Luc for 24 h (A), ISRE-Luc (B), or NF-κB-Luc (C), along with 100 ng to 400 ng of the HA-3CL-expressing plasmid followed by SeV exposure for 6 h. The results are presented relative to the luciferase activity in control cells with the luciferase reporter and empty vector (top). Expression of the indicated transfected plasmids was detected by immunoblotting with an anti-3CL antibody (1:1000) (below). *P < 0.05; **P < 0.001; ***P < 0.001 (unpaired, two-tailed Student’s t-test). Data are representative of at least three independent experiments.