title: Innate immunity to virus infection.
abstract: The innate immune system is essential for the initial detection of invading viruses and subsequent activation of adaptive immunity. Three classes of receptors, designated retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), Toll-like receptors (TLRs), and nucleotide oligomerization domain (NOD)-like receptors (NLRs), sense viral components, such as double-stranded RNA (dsRNA), single-stranded RNA, and DNA. RLRs and TLRs play essential roles in the production of type I interferons (IFNs) and proinflammatory cytokines in cell type-specific manners. While the RLRs play essential roles in the recognition of RNA viruses in various cells, plasmacytoid dendritic cells utilize TLRs for detecting virus invasion. NLRs play a role in the production of mature interleukin-1 beta to dsRNA stimulation. Activation of innate immune cells is critical for mounting adaptive immune responses. In this review, we discuss recent advances in our understanding of the mechanisms of viral RNA recognition by these different types of receptors and its relation to acquired immune responses.
authors.affiliation: Laboratory of Host Defense, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Takeuchi
authors.forename: Shizuo
authors.initials: S
authors.lastname: Akira
mesh_terms: D000818:Animals; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004722:Endoribonucleases / Q000276:immunology / Q000378:metabolism; D054884:Host-Pathogen Interactions / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D007113:Immunity, Innate; D007370:Interferon Type I / Q000276:immunology; D000072640:Interferon-Induced Helicase, IFIH1; D051336:Mitochondrial Membranes / Q000276:immunology; D024101:Mitochondrial Proteins / Q000276:immunology; D020365:RNA Helicases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012327:RNA Virus Infections / Q000276:immunology* / Q000503:physiopathology / Q000517:prevention & control; D012328:RNA Viruses / Q000502:physiology; D012367:RNA, Viral / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D011971:Receptors, Immunologic; D015398:Signal Transduction / Q000276:immunology; D054875:Ubiquitination / Q000276:immunology
chemical_list: D007370:Interferon Type I; D024101:Mitochondrial Proteins; C527006:NLRX1 protein, human; D012367:RNA, Viral; D011971:Receptors, Immunologic; C520569:DHX58 protein, human; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease; C452820:RIGI protein, human; C452815:IFIH1 protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases; D000072640:Interferon-Induced Helicase, IFIH1; D020365:RNA Helicases