Autoimmunity caused by constitutive activation of cytoplasmic viral RNA sensors

RIG-I-like receptors (RLRs) are well-known viral sensors that trigger the antiviral interferon (IFN) response by recognizing the non-self signatures of viral RNAs. The proper induction of the IFN response is known to play a crucial role in protecting against viral infections, whereas aberrant activation can lead to autoimmune disorders. We herein provided an overview of the antiviral IFN response and autoimmunity, with a focus on recent studies describing autoimmunity caused by mutations in the cytoplasmic viral RNA sensor, melanoma differentiation-associated gene 5 (MDA5).