Mouse hepatitis virus does not induce beta interferon synthesis and does not inhibit its induction by double-stranded RNA

Mouse hepatitis virus (MHV) does not induce interferon (IFN) production in fibroblasts or bone marrow-derived dendritic cells. In this report, we show that the essential IFN-beta transcription factors NF-kappa B and IFN regulatory factor 3 are not activated for nuclear translocation and gene induction during infection. However, MHV was unable to inhibit the activation of these factors and subsequent IFN-beta production induced by poly(I:C). Further, MHV infection did not inhibit IFN-beta production mediated by known host pattern recognition receptors (PRRs) (RIG-I, Mda-5, and TLR3). These results are consistent with the notion that double-stranded RNA, produced during MHV infection, is not accessible to cellular PRRs.