Inhibition of type I IFN-induced luciferase activity in 2′5′

OASLuc L cells by recombinant muIfnar-2a. Murine L929 cells were stably transfected with a cDNA encoding luciferase linked to the IFN responsive promoter 2′5′oligoadenylate synthetase (2′5′OASLuc L cells). Different concentrations of recombinant muIfnar-2a were preincubated with the indicated concentrations of type I IFN at 37°C for 1 hour: (A) 10 IU/mL (▪), 1 IU/mL (▴), or 0 (▾) recombinant muIFNα1 or (B) 10 IU/mL (▪), 1 IU/mL (▴), or 0 (▾) recombinant muIFNβ, and then added to 2′5′OASLuc L cells and incubated for a further 7 hours. The data are presented as the mean ± SEM (n = 8) fold induction of luciferase activity.