Fig. 1

SARS-CoV-2 NSP13 suppresses type I and type II IFN signaling. A NSP13 suppresses IFN-β- and IFN-γ- induced ISRE and GAS promoter activity. HEK293T cells were transfected with pISRE-Luc or pGAS-Luc, SV40 Renilla luciferase and increasing doses of NSP13 plasmid (200, 400 and 600 ng). At 24 h post transfection, cells were stimulated by 1000 U/mL of IFN-β or 100 ng/mL of IFN-γ. Dual luciferase activity was measured 24 h post IFN treatment. B–G Suppression of IFN-β and IFN-γ signaling by NSP13. A549 cells were either mock transfected or transfected with NSP13 plasmid. At 26 h post transfection, cells were stimulated by 1000 U/mL IFN-β or 100 ng/mL IFN-γ for 6 h. ISG transcripts were analyzed by RT-qPCR. Results were representative of three independent experiments. The statistical significance of the differences between the indicated groups was evaluated by one-tailed Student t test for unpaired samples with equal variance. *P < 0.05. **P < 0.01. ***P < 0.001