title: BCR targeting of biotin-{alpha}-galactosylceramide leads to enhanced presentation on CD1d and requires transport of BCR to CD1d-containing endocytic compartments.
abstract: CD1d is a non-polymorphic MHC class I-related protein that binds and presents glycolipid antigens to T cell antigen receptors expressed by NK-like T (NKT) cells. CD1d-dependent immune responses play critical roles in infectious disease, autoimmunity, allergy and cancer. We tested the hypothesis that B cell antigen receptor (BCR) targeting of a biotin-modified version of the CD1d-binding antigen alpha-galactosylceramide (biotin-alpha-GalCer) results in enhanced murine CD1d-mediated presentation as compared with presentation of non-targeted biotin-alpha-GalCer. Presentation of BCR-targeted antigen to NKT cells was enhanced 100- to 1000-fold compared with non-targeted antigen. CD1d presentation of BCR-targeted antigen was observed after 4 h treatment, consistent with a requirement for endosomal trafficking. Furthermore, unlike non-targeted antigen, BCR-targeted antigen was not loaded directly onto cell-surface CD1d. Blocking BCR signaling with the Syk tyrosine kinase inhibitor piceatannol inhibited presentation of BCR-targeted antigen but not non-targeted antigen. Piceatannol blocked transport of the BCR to CD1d-containing endosomes, showing that intersection of BCR-targeted antigen with endosomes is required for enhanced mCD1d antigen presentation. Our data suggest that the BCR facilitates capture of low quantities of mCD1d antigens to enhance CD1d-dependent immune responses.
authors.affiliation: Department of Microbiology and Immunology, 632W Borwell Building, Dartmouth Medical School, One Medical Center Drive, Lebanon, NH 03756, USA.
authors.forename: Gillian A
authors.initials: GA
authors.lastname: Lang
authors.forename: Petr A
authors.initials: PA
authors.lastname: Illarionov
authors.forename: Aharona
authors.initials: A
authors.lastname: Glatman-Freedman
authors.forename: Gurdyal S
authors.initials: GS
authors.lastname: Besra
authors.forename: Mark L
authors.initials: ML
authors.lastname: Lang
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects / Q000276:immunology*; D018949:Antigens, CD1 / Q000276:immunology*; D055610:Antigens, CD1d; D001710:Biotin / Q000031:analogs & derivatives* / Q000276:immunology / Q000494:pharmacology; D002460:Cell Line; D011992:Endosomes / Q000276:immunology*; D004792:Enzyme Precursors / Q000037:antagonists & inhibitors / Q000276:immunology; D005699:Galactosylceramides / Q000276:immunology* / Q000494:pharmacology; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D047908:Intracellular Signaling Peptides and Proteins; D007694:Killer Cells, Natural / Q000276:immunology; D051379:Mice; D021381:Protein Transport / Q000187:drug effects / Q000276:immunology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000276:immunology; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*; D013267:Stilbenes / Q000494:pharmacology; D000072377:Syk Kinase; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D018949:Antigens, CD1; D055610:Antigens, CD1d; D004792:Enzyme Precursors; D005699:Galactosylceramides; D015395:Histocompatibility Antigens Class I; D047908:Intracellular Signaling Peptides and Proteins; D011947:Receptors, Antigen, B-Cell; D013267:Stilbenes; C050344:biotin-galactosylceramide; C041525:3,3',4,5'-tetrahydroxystilbene; D001710:Biotin; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; C000606897:Syk protein, mouse