title: Capacities of migrating CD1b+ lymph dendritic cells to present Salmonella antigens to naive T cells.
abstract: Dendritic cells (DCs) are well known as professional antigen-presenting cells (APC) able to initiate specific T-cell responses to pathogens in lymph nodes (LN) draining the site of infection. However, the respective contribution of migratory and LN-resident DCs in this process remains unclear. As DC subsets represent important targets for vaccination strategies, more precise knowledge of DC subsets able to present vaccine antigens to T cells efficiently is required. To investigate the capacities of DCs migrating in the lymph (L-DCs) to initiate a specific T-cell response, we used physiologically generated DCs collected from a pseudoafferent lymphatic cannulation model in sheep. The CD1b+ L-DCs were assessed for presenting antigens from the vaccine attenuated strain of Salmonella enterica serovar Abortusovis. CD1b+ L-DCs were able to phagocytose, process and to present efficiently Salmonella antigens to effector/memory T cells in vitro. They were shown to be efficient APC for the priming of allogeneic naive T cells associated with inducing both IFN-γ and IL-4 responses. They were also efficient in presenting Salmonella antigens to autologous naive T cells associated with inducing both IFN-γ and IL-10 responses. The capacities of L-DCs to process and present Salmonella antigens to T cells were investigated in vivo after conjunctival inoculation of Salmonella. The CD1b+ L-DCs collected after inoculation were able to induce the proliferative response of CD4+ T cells suggesting the in vivo capture of Salmonella antigens by the CD1b+ L-DCs, and their potential to present them directly to CD4+ T cells. In this study, CD1b+ L-DCs present potential characteristics of APC to initiate by themselves T cell priming in the LN. They could be used as target cells for driving immune activation in vaccinal strategies.
authors.affiliation: UR1282 Infectiologie Animale et Santé Publique, Institut National de la Recherche Agronomique, Nouzilly, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Olivier
authors.forename: Benjamin
authors.initials: B
authors.lastname: Foret
authors.forename: Yves
authors.initials: Y
authors.lastname: Le Vern
authors.forename: Laurence A
authors.initials: LA
authors.lastname: Guilloteau
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D018949:Antigens, CD1 / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002465:Cell Movement / Q000276:immunology; D002478:Cells, Cultured; D003228:Conjunctiva / Q000276:immunology / Q000382:microbiology; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D004705:Endocytosis / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D015847:Interleukin-4 / Q000276:immunology / Q000378:metabolism; D019041:L-Selectin / Q000276:immunology / Q000378:metabolism; D008196:Lymph / Q000166:cytology / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D010587:Phagocytosis / Q000276:immunology; D012480:Salmonella Infections / Q000276:immunology / Q000382:microbiology; D019779:Salmonella enterica / Q000276:immunology*; D012756:Sheep; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D018949:Antigens, CD1; C419394:CD1b antigen; D019041:L-Selectin; D015847:Interleukin-4; D007371:Interferon-gamma