Fig. 2.

Stimulatory activity of different SARS-COV-2 lineages towards IFN-β promoter was investigated in Calu-3 cells transfected with the IFN-β promoter-mediated firefly luciferase (pIFN-β) and the SV40 promoter-mediated Renilla luciferase reporter plasmids. At 12h post-transfection, cells were mock-infected or infected with a MOI=0.01 of selected virus variants. Firefly and Renilla luciferase activities were estimated with respect to the mock sample at 48h post-infection. Three (n=3) independent experiments were performed. Representative data are presented as mean logarithm values of relative luminescence unit (RLU) ± standard deviations (SD). With respect to Wuhan-1 reference strain, significance was determined using unpaired, two-tailed Student's t-test as p<0.0001, ^⁎⁎⁎⁎; p>0.05, n.s.