title: Invariant chain is a new chaperone for TLR7 in B cells.
abstract: The innate immune system provides the first barrier against pathogens. Intracellular Toll-like receptors (TLR3, 7 and 9) localise in endosomes and sense nucleotides from viruses and bacteria. This recognition induces their conformational changes resulting in the production of proinflammatory cytokines and MHC class II (MHCII) antigenic presentation. In the absence of stimulation, TLRs are retained in the endoplasmic reticulum. Upon stimulation, they relocate to the endo-lysosomal compartment, allowing the recruitment of the adaptor molecules, MyD88 or TRIF. Increasing evidences describe a cross talk between proteins that regulate both innate and adaptive immune responses. For example, proteolytic enzymes which are required for breaking down exogenous antigen to generate suitable peptides for MHCII molecules are also essential to activate endosomal TLRs and MHCII molecules were recently described to regulate TLR signalling. But other proteins are possibly involved and regulated differentially between cell types. We have observed that intracellular TLR trafficking and signalling in B cells are different from dendritic cells and macrophages and involved the MHCII chaperone molecule, the invariant chain (Ii).
authors.affiliation: Division of Immunology, Children Hospital, Boston, MA 02115, USA.
authors.forename: Mira
authors.initials: M
authors.lastname: Tohmé
authors.affiliation: INEM, U1151-CNRS UMR 8253, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Faculté de médecine, 75015 Paris, France. Electronic address: benedicte.manoury@inserm.fr.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Manoury
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000235:genetics / Q000276:immunology; D017951:Antigen Presentation; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics / Q000276:immunology*; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D011992:Endosomes / Q000276:immunology / Q000378:metabolism; D005786:Gene Expression Regulation; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D018832:Molecular Chaperones / Q000235:genetics / Q000276:immunology*; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000276:immunology; D021381:Protein Transport; D015398:Signal Transduction; D051199:Toll-Like Receptor 7 / Q000235:genetics / Q000276:immunology*
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D000942:Antigens, Bacterial; D000944:Antigens, Differentiation, B-Lymphocyte; D000956:Antigens, Viral; D000949:Histocompatibility Antigens Class II; C507779:MYD88 protein, human; D018832:Molecular Chaperones; D053594:Myeloid Differentiation Factor 88; C470409:TICAM1 protein, human; C495348:TLR7 protein, human; D051199:Toll-Like Receptor 7; C045084:invariant chain
keywords: B cells; Invariant chain; MHC class II molecules; TLRs