Study of CD40 ligand expression in B-cell chronic lymphocytic leukemia.
CD40 ligand (CD40L) is a membrane molecule that plays a key role in T cell-B cell cooperation, providing B cells the helper signals needed for activation, proliferation, differentiation and prevention of apoptosis. Patients with B-cell chronic lymphocytic leukemia (B-CLL) were studied to verify the following hypotheses: a) whether defective CD40L expression on activated T cells could account for deficient helper signals and therefore for hypogammaglobulinemia; b) whether aberrant CD40L expression on B cells could be a mechanism by which leukemic cells stimulate themselves via CD40 to escape apoptosis. Results showed physiological expression of CD40L on in vitro activated CD4+ cells, while this expression was absent on fresh and activated B cells. Abnormalities in CD40/CD40L interaction do not seem to play a role either in the pathogenesis of hypogammaglobulinemia or in lymphocyte accumulation in B-CLL.
Brugnoni
D
D
Servizio di Immunologia Clinica, Spedali Civili di Brescia, Italy.
Rossi
G
G
Tucci
A
A
Cattaneo
R
R
Airò
P
P
D000328:Adult; D000361:Agammaglobulinemia / Q000209:etiology; D000368:Aged; D000369:Aged, 80 and over; D023201:CD40 Ligand; D005260:Female; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications / Q000235:genetics*; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D008875:Middle Aged; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism; D014407:Tumor Cells, Cultured
D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D023201:CD40 Ligand