title: Platelet-associated CD154 in immune thrombocytopenic purpura.
abstract: CD40-ligand (CD154) is expressed on activated CD4+ T lymphocytes and is essential for the T cell-dependent activation of B lymphocytes. CD154 is also expressed at the activated platelet surface. In this study, we show that platelet-associated CD154 is increased in immune thrombocytopenic purpura (ITP), a disease characterized by an autoimmune response against proteins of the platelet membrane. CD154 and its messenger RNA were also present in increased amounts in the megakaryocytes of patients with ITP. We found that platelet-associated CD154 is competent to induce the CD40-dependent proliferation of B lymphocytes, and we observed an in vitro CD154-dependent production of antibodies to the GPIIb/IIIa complex (integrin alphaIIbbeta3) when platelets and peripheral blood B lymphocytes from ITP patients with circulating anti-GPIIb/IIIa antibody were cultured together. Therefore, platelet-associated CD154 expression is increased in ITP and is able to drive the activation of autoreactive B lymphocytes in this disease.
authors.affiliation: CNRS FRE 2617 and UMR 5540, Université de Bordeaux 2, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Solanilla
authors.forename: Jean-Max
authors.initials: JM
authors.lastname: Pasquet
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Viallard
authors.forename: Cécile
authors.initials: C
authors.lastname: Contin
authors.forename: Christophe
authors.initials: C
authors.lastname: Grosset
authors.forename: Julie
authors.initials: J
authors.lastname: Déchanet-Merville
authors.forename: Maryse
authors.initials: M
authors.lastname: Dupouy
authors.forename: Marc
authors.initials: M
authors.lastname: Landry
authors.forename: Francis
authors.initials: F
authors.lastname: Belloc
authors.forename: Paquita
authors.initials: P
authors.lastname: Nurden
authors.forename: Patrick
authors.initials: P
authors.lastname: Blanco
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Moreau
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Pellegrin
authors.forename: Alan T
authors.initials: AT
authors.lastname: Nurden
authors.forename: Jean
authors.initials: J
authors.lastname: Ripoche
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D001792:Blood Platelets / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology; D023201:CD40 Ligand / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D008213:Lymphocyte Activation; D011696:Purpura, Thrombocytopenic / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology
chemical_list: D023201:CD40 Ligand