title: CD40 ligand-independent B cell activation revealed by CD40 ligand-deficient T cell clones: evidence for distinct activation requirements for antibody formation and B cell proliferation.
abstract: We report the capacity of CD40 ligand (CD40L)-negative T cell clones to activate human B cells. CD40L-negative T cells induce a level of B cell proliferation 10-20% of that seen with normal T cells. The signal provided by the negative clones is synergistic with that derived from a CD40L transfectant, and restores B cell proliferation to normal levels, showing that CD40L-negative T cell clones are not inherently inhibitory for B cells. Although their capacity to induce proliferation was much reduced, CD40L-negative T cell clones were still strong inducers of B cell differentiation to plasma cells. This differentiation to plasma cells was inhibited by a CD40L transfectant. The data are discussed with regard to the normal in vivo mechanism for maintaining B cell memory and memory antibody responses to T-dependent antigens.
authors.affiliation: Basel Institute for Immunology, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Lane
authors.forename: C
authors.initials: C
authors.lastname: Burdet
authors.forename: F
authors.initials: F
authors.lastname: McConnell
authors.forename: A
authors.initials: A
authors.lastname: Lanzavecchia
authors.forename: E
authors.initials: E
authors.lastname: Padovan
mesh_terms: D000917:Antibody Formation / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D023201:CD40 Ligand; D002455:Cell Division; D002999:Clone Cells; D006801:Humans; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D008562:Membrane Glycoproteins; D023201:CD40 Ligand