P130 IRF9 binds to the interferon-B promoter and mediates interferon production in the absence of IRF3 in response to double-stranded RNA

IntroductionGiven its importance in IFNβ and IFN-stimulated gene (ISG) production, IFN regulatory factor 3 (IRF3) is rapidly degraded or inactivated by most viruses. As cells retain production of IFNβ in the absence of IRF3, we investigated which IRF compensates for IRF3.MethodsWe focused on fibroblasts, as these are potent inducers of IFNβ and thus play a key role in pathogen defense. Primary fibroblasts from IRF1−/−IRF3−/−, IRF7−/−IRF3−/− and …