title: Surface molecules on stimulated plasmacytoid dendritic cells are sufficient to cross-activate resting myeloid dendritic cells.
abstract: Human plasmacytoid dendritic cells (pDCs) and myeloid dendritic cells (mDCs) are 2 types of antigen-presenting cells that exert complementary roles in innate immune responses. We demonstrated previously that in the presence of suboptimal stimulation or when only 1 dendritic cell type is directly stimulated, contact-dependent crosstalk between mDCs and pDCs leads to the activation of both cell types and thus provides them with the ability to induce an optimal T-cell response. The precise mechanism is currently unknown. Here we demonstrate that pDCs, unable to secrete soluble factors because of previous stimulation, induce optimal mDC maturation, indicating that resting immature mDCs are fully competent to respond to Toll-like receptor-9-engaged pDCs in the absence of soluble factors. Thus, we conclude that immature mDCs already express receptors recognized by ligands that are upregulated on the surface of activated pDCs. Intercellular adhesion molecule-1 upregulated by activated pDCs may play a role in a donor-dependent manner.
authors.affiliation: Novartis Vaccines and Diagnostics, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: Cantisani
authors.forename: Chiara
authors.initials: C
authors.lastname: Sammicheli
authors.forename: Simona
authors.initials: S
authors.lastname: Tavarini
authors.forename: Ugo
authors.initials: U
authors.lastname: D'Oro
authors.forename: Andreas
authors.initials: A
authors.lastname: Wack
authors.forename: Diego
authors.initials: D
authors.lastname: Piccioli
mesh_terms: D017951:Antigen Presentation; D000954:Antigens, Surface / Q000378:metabolism*; D002450:Cell Communication; D002454:Cell Differentiation / Q000276:immunology; D002469:Cell Separation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D007113:Immunity, Innate; D007114:Immunization; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology / Q000378:metabolism; D007365:Intercellular Junctions / Q000378:metabolism; D022423:Myeloid Cells / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D051217:Toll-Like Receptor 9 / Q000276:immunology / Q000378:metabolism
chemical_list: D000954:Antigens, Surface; D051217:Toll-Like Receptor 9; D018799:Intercellular Adhesion Molecule-1