title: Observations on memory B-cell development.
abstract: We dissect in this article the roles of CD40 and its ligand in memory B-cell formation. Our data indicate that CD40 ligation does not directly lead to GC formation but it plays an indirect role related to maturation of helper T cells; signalling is bidirectional, to B cells, via CD40, upregulating cytokine receptor expression and to T cells, via CD40L, causing secretion of cytokines necessary for GC initiation. Later in the GC, CD40 selects mutated B cells for entry into the memory pool. This second T-cell-mediated CD40 ligation has consequences distinct from the first (rescue versus proliferation) that arise from rewiring of CD40 signal transduction pathways.
authors.affiliation: Department of Immunology, Royal Postgraduate Medical School, Hammersmith Hospital, Du Cane Road, London, W12 0NN, U.K.
authors.forename: D
authors.initials: D
authors.lastname: Gray
authors.forename: S
authors.initials: S
authors.lastname: Bergthorsdottir
authors.forename: D
authors.initials: D
authors.lastname: van Essen
authors.forename: M
authors.initials: M
authors.lastname: Wykes
authors.forename: J
authors.initials: J
authors.lastname: Poudrier
authors.forename: K
authors.initials: K
authors.lastname: Siepmann
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D019013:CD40 Antigens / Q000378:metabolism; D023201:CD40 Ligand; D002454:Cell Differentiation; D018858:Germinal Center / Q000166:cytology / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory; D008562:Membrane Glycoproteins / Q000378:metabolism; D010950:Plasma Cells / Q000166:cytology / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology / Q000276:immunology
chemical_list: D019013:CD40 Antigens; D008562:Membrane Glycoproteins; D023201:CD40 Ligand