Cytoplasmic Viral RNA Sensors: RIG-I-Like Receptors

The interferon (IFN) response is a powerful system that was evolutionarily acquired by vertebrates including mammals to protect against viral infection. The cytoplasmic RNA helicases, RIG-I-like receptors (RLRs), were discovered in 2004 as viral sensors that trigger the antiviral IFN response by recognizing the nonself signatures of viral RNAs. The mechanisms underlying the recognition of viral RNAs and signal transduction leading to the production of type I IFN have been intensively studied following the discovery of RLRs. Moreover, a dysregulation in the expression of RLR or aberrant RLR signaling has been implicated in the development of a number of autoimmune diseases. We herein provide an overview of recent advances in RLR research and discussed future directions.