title: Acquisition of CD40 expression during murine B-cell differentiation.
abstract: Expression of CD40 on mouse cells was investigated comparing the binding to cells of a monoclonal antibody against CD40, to that of a soluble fusion protein consisting of the extracellular domains of the mouse CD40-ligand. The analysis of a series of established cell lines failed to demonstrate expression of CD40 on pro- or pre-B cells, and indicated that CD40 expression was restricted to cells that had undergone productive heavy- and light-chain gene rearrangements, and expressed surface Ig. In cells from normal mice, CD40 first becomes detectable, although at low levels, on a subset of small pre-B-II cells in bone marrow, the levels of CD40 expression increasing thereafter during B-cell maturation. Thus, immature B cells (IgM+ IgDlo B220lo) express intermediate levels of CD40, and mature B cells (IgM+ IgDhi B220hi) express high levels of CD40. Anatomical location also seems to correlate with the levels of CD40 expression, as B cells expressing the highest levels of CD40 were found in lymph nodes and Peyer's patches.
authors.affiliation: Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Grandien
authors.forename: A
authors.initials: A
authors.lastname: Brás
authors.forename: C
authors.initials: C
authors.lastname: Martinez
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology; D019013:CD40 Antigens / Q000096:biosynthesis* / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002460:Cell Line; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D005434:Flow Cytometry; D017493:Leukocyte Common Antigens / Q000276:immunology; D051917:Leukosialin; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010581:Peyer's Patches / Q000276:immunology; D012795:Sialoglycoproteins / Q000276:immunology; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D019013:CD40 Antigens; D051917:Leukosialin; D012795:Sialoglycoproteins; C497863:Spn protein, mouse; D017493:Leukocyte Common Antigens