Interferon-Inducible Protein IFI35 Negatively Regulates RIG-I Antiviral Signaling and Supports Vesicular Stomatitis Virus Replication

Abstract

Mammalian cells employ a variety of mechanisms, including production of interferons (IFNs), to counteract invading pathogens. In this study, we identified a novel role for a cellular protein, IFN-inducible protein 35 (IFP35/IFI35), in negatively regulating the host IFN response during vesicular stomatitis virus (VSV) infection. Specifically, we found that IFI35 inhibited activation of the RNA sensor, the retinoic acid-inducible gene I (RIG-I), leading to inhibition of IFN production and thus resulting in better replication of VSV. The identification of a cellular factor that attenuates the IFN response will have implications toward understanding inflammatory diseases in humans that have been found to be associated with defects in the regulation of host IFN production, such as systemic lupus erythematosus and psoriasis.