title: The active role played by xenogeneic endothelial cells in the indirect presentation pathway is not lymphocyte trans-co-stimulation.
abstract: The human CD4+ T lymphocyte response to major histocompatibility complex (MHC) class II-negative porcine endothelial cells is dependent on the presence of human monocytes through a human leukocyte antigen (HLA) class II-restricted indirect presentation pathway. Because the role of porcine endothelial cells had been previously shown to do more than simply supply xenopeptides, co-stimulatory signals were analysed. Endothelial cells were shown to express the CD54, CD58, CD59 and CD86 transcripts; however, no membrane B7 molecule could be detected. Blocking experiments in a direct pathway model confirmed that porcine endothelial cells could provide co-stimulatory signals to human T cells through the CD2 and LFA-1 pathways. Nevertheless, the proliferation achieved in the indirect presentation model required co-stimulation by LFA-1, CD2 and CD28, engaged by co-stimulation molecules expressed in the cis-form by the human monocytes. These results clearly show that the active role played by the endothelial cells in the indirect pathway is not lymphocyte trans-co-stimulation and suggest that cis-co-stimulation dominates trans-co-stimulation when both are present.
authors.affiliation: EA 3249 Cellules Hématopoïétiques, Hémostase et Greffe and IFR 135 Imagerie et Exploration fonctionelles, Université François Rabelais, Tours, France.
authors.forename: Angélique
authors.initials: A
authors.lastname: Brossay
authors.forename: Solène
authors.initials: S
authors.lastname: Harang
authors.forename: Olivier
authors.initials: O
authors.lastname: Hérault
authors.forename: Pierre
authors.initials: P
authors.lastname: Bardos
authors.forename: Hervé
authors.initials: H
authors.lastname: Watier
mesh_terms: D000069594:Abatacept; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology; D015478:Antigens, Heterophile / Q000276:immunology*; D001011:Aorta / Q000166:cytology; D018122:B7-1 Antigen / Q000235:genetics / Q000276:immunology; D051940:B7-2 Antigen; D018801:CD2 Antigens / Q000276:immunology / Q000378:metabolism; D000071178:CD48 Antigen; D018968:CD58 Antigens / Q000235:genetics / Q000276:immunology; D018957:CD59 Antigens / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000276:immunology*; D006801:Humans; D018796:Immunoconjugates / Q000276:immunology / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000276:immunology; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D013552:Swine; D013556:Swine, Miniature; D014183:Transplantation, Heterologous / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D015478:Antigens, Heterophile; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D018801:CD2 Antigens; D000071178:CD48 Antigen; D018968:CD58 Antigens; D018957:CD59 Antigens; C497964:CD86 protein, human; D018796:Immunoconjugates; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1; D000069594:Abatacept