title: Nucleic acid-sensing TLRs and autoimmunity: novel insights from structural and cell biology.
abstract: Invasion of pathogenic microorganisms or tissue damage activates innate immune signaling receptors that sample subcellular locations for foreign molecular structures, altered host molecules, or signs of compartment breaches. Upon engagement of innate immune receptors an acute but transient inflammatory response is initiated, aimed at the clearance of pathogens and cellular debris. Among the molecules that are sensed are nucleic acids, which activate several members of the transmembrane Toll-like receptor (TLR) family. Inappropriate recognition of nucleic acids by TLRs can cause inflammatory pathologies and autoimmunity. Here, we review the mechanisms involved in triggering nucleic acid-sensing TLRs and indicate checkpoints that restrict their activation to endolysosomal compartments. These mechanisms are crucial to sample the content of endosomes for nucleic acids in the context of infection or tissue damage, yet prevent accidental activation by host nucleic acids under physiological conditions. Decoding the molecular mechanisms that regulate nucleic acid recognition by TLRs is central to understand pathologies linked to unrestricted nucleic acid sensing and to develop novel therapeutic strategies.
authors.affiliation: Institute of Innate Immunity, University Hospitals Bonn, Bonn, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Pelka
authors.affiliation: Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Shibata
authors.affiliation: Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Miyake
authors.affiliation: Institute of Innate Immunity, University Hospitals Bonn, Bonn, Germany.|German Center for Neurodegenerative Diseases, Bonn, Germany.|Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Eicke
authors.initials: E
authors.lastname: Latz
mesh_terms: D000818:Animals; D015551:Autoimmunity; D006706:Homeostasis; D054884:Host-Pathogen Interactions; D006801:Humans; D007113:Immunity, Innate; D007249:Inflammation; D009696:Nucleic Acids / Q000276:immunology*; D015398:Signal Transduction; D051193:Toll-Like Receptors / Q000378:metabolism*
chemical_list: D009696:Nucleic Acids; D051193:Toll-Like Receptors
keywords: TLR; UNC93B1; autoimmunity; nucleic acid sensing