Platelet-associated CD154 in immune thrombocytopenic purpura.
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.
Solanilla
Anne
A
CNRS FRE 2617 and UMR 5540, Université de Bordeaux 2, France.
Pasquet
Jean-Max
JM
Viallard
Jean-François
JF
Contin
Cécile
C
Grosset
Christophe
C
Déchanet-Merville
Julie
J
Dupouy
Maryse
M
Landry
Marc
M
Belloc
Francis
F
Nurden
Paquita
P
Blanco
Patrick
P
Moreau
Jean-François
JF
Pellegrin
Jean-Luc
JL
Nurden
Alan T
AT
Ripoche
Jean
J
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
D023201:CD40 Ligand