title: CD40 ligand-dependent maturation of human monocyte-derived dendritic cells by activated platelets.
abstract: Atherosclerosis is defined as an inflammatory immunological disease that is triggered by platelet activation, endothelial injury and consequent innate and adaptive immune processes. Dendritic cells are critical for the cell-mediated arm of the immune response as they activate naïve T cells after maturation. Platelets play a crucial role in thrombus formation in the injured vessel walls. We investigated the role of resting and thrombin-activated platelets in dendritic cell maturation in vitro using platelets and monocyte-derived dendritic cells from healthy donors. Resting platelet supernatants did not affect maturation, whereas supernatants from thrombin-activated platelets induced dendritic cell maturation as demonstrated by FACS analysis of HLA-DR expression. This effect was inhibited by anti CD40 ligand antibody, but not by aspirin pretreatment of platelets. Supernatants of platelet-dendritic cell co-cultures induced augmented monocyte migration when platelets were activated by thrombin, again reversible by blocking CD40 ligand. These data show that activated platelets trigger dendritic cell maturation independent of cyclooxygenase-derived arachidonic acid metabolites by mechanisms involving CD40 ligand, which is also involved in monocyte chemotactic mediator release from platelets and dendritic cells. The results of this study suggest a role of CD40 ligand from activated platelets in connecting innate and adaptive immunity.
authors: Dept Internal Medicine, University of Innsbruck, Austria.
authors: N C
authors: NC
authors: Kaneider
authors: A
authors: A
authors: Kaser
authors: H
authors: H
authors: Tilg
authors: G
authors: G
authors: Ricevuti
authors: C J
authors: CJ
authors: Wiedermann
mesh_terms: D001792:Blood Platelets / Q000276:immunology / Q000378:metabolism; D023201:CD40 Ligand / Q000502:physiology*; D002450:Cell Communication / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D009000:Monocytes / Q000166:cytology* / Q000276:immunology; D015539:Platelet Activation / Q000276:immunology*
chemical_list: D023201:CD40 Ligand