title: MHC class I-mediated exogenous antigen presentation by exosomes secreted from immature and mature bone marrow derived dendritic cells.
abstract: Exosomes are 50-90 nm vesicles with antigen presenting ability carrying major histocompatibility complex (MHC) class I, class II, abundant co-stimulatory molecules and some tetraspan proteins. Although dendritic cells (DCs) are one of the professional antigen presenting cells capable of presenting exogenous antigens in MHC class I-mediated antigen specific manner (cross-presentation), the cross-presentation ability by exosomes from immature or mature DCs are unknown. Here we show that exosomes released from ovalbumin (OVA) protein-pulsed bone marrow derived dendritic cells (BM-DCs) weakly present the peptide determinants to OVA specific MHC class I-restricted CD8(+) T cell hybridomas. The exosomes secreted by OVA(257-264) peptide- or OVA protein-pulsed mature BM-DCs activated OVA specific MHC class I-restricted T cell hybridomas more efficiently than those from immature BM-DCs. Transporters associated with antigen processing (TAP) deficient mice-derived BM-DCs were also used to examine whether functional TAP activity was required for cross-presentation by exosomes. The exosomes obtained from OVA(257-264) peptide-pulsed BM-DCs derived from TAP(-/-) mice showed a significant antigen presenting ability to OVA specific MHC class I-restricted T cell hybridomas. Altogether, our data indicate that BM-DCs secrete exosomes with weak cross-presentation ability.
authors.affiliation: Department of Immunology, Yokohama City University, School of Medicine, 3-9 Fukuura, Kanazawa-ku, 236-0004, Yokohama, Japan.
authors.forename: Saho
authors.initials: S
authors.lastname: Utsugi-Kobukai
authors.forename: Haruka
authors.initials: H
authors.lastname: Fujimaki
authors.forename: Chie
authors.initials: C
authors.lastname: Hotta
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakazawa
authors.forename: Mutsuhiko
authors.initials: M
authors.lastname: Minami
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology* / Q000502:physiology; D001854:Bone Marrow Cells / Q000276:immunology* / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology* / Q000378:metabolism; D006825:Hybridomas / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D015395:Histocompatibility Antigens Class I