Innate immune RNA-sensing pattern-recognition receptors (RNA-sensing PRRs)

Innate immune RNA-sensing pattern-recognition receptors (PRRs) are a specialized group of proteins responsible for detecting foreign or mislocalized RNA, primarily from viruses or damaged host cells. These receptors are strategically located within the cell: Toll-like receptors (TLRs) such as TLR3, TLR7, and TLR8 reside in endosomes, while RIG-I-like receptors (RLRs) like RIG-I and MDA5 are found in the cytoplasm (Chow et al., 2018, "RIG-I and Other RNA Sensors in Antiviral Immunity"). Upon binding to specific RNA motifs—such as double-stranded RNA or 5'-triphosphorylated RNA—these receptors trigger signaling cascades involving adapter proteins like TRIF, MyD88, or MAVS. This activation leads to the production of type I interferons and pro-inflammatory cytokines, which are essential for establishing an antiviral state and modulating the adaptive immune response (Wu and Chen, 2014, "Innate immune sensing and signaling of cytosolic nucleic acids"). Dysregulation of these pathways is linked to various pathologies, including chronic viral infections, autoimmune disorders like systemic lupus erythematosus, and autoinflammatory conditions (Schlee and Hartmann, 2016, "Discriminating self from non-self in nucleic acid sensing"). Consequently, these receptors are major therapeutic targets; agonists are being developed as vaccine adjuvants and cancer immunotherapies, while antagonists are explored for treating inflammatory and autoimmune diseases (Kawai and Akira, 2010, "The role of pattern-recognition receptors in innate immunity").

Other names

RNA pattern-recognition receptorsNucleic acid-sensing receptorsEndosomal and cytosolic RNA sensorsRNA-sensing PRRs

Agonism of endosomal or cytosolic sensors to induce type I interferon and pro-inflammatory cytokine production for antiviral or antitumor effects; Antagonism to inhibit aberrant immune activation in autoimmune diseases.