title: Phenotype and function of human B cells expressing CD70 (CD27 ligand).
abstract: CD70, the cellular ligand of the tumor necrosis factor receptor family member CD27, can be found on a limited number of germinal center (GC) B cells in some tonsils, on scattered lymphocytes residing in secondary lymphoid organs, and on a fraction of the circulating B cell population. Due to the restricted expression of CD70 in vivo, we analyzed signals that determine CD70 expression levels and characterized the phenotype and function of CD70+ B cells. Expression of CD70 on B cells activated in vitro was found to be dependent on the continuous presence of a B cell antigen receptor cross-linking agent, and induced or potentiated by CD40 ligation but was down-modulated by the Th2 cytokines interleukin (IL)-4 and IL-13. Both in peripheral blood and tonsil cell suspensions, CD70+ B cell subpopulations were found to be enriched for CD27- and IgG-expressing cells, but contained less IgD+ B cells. Additional analysis of markers which define specific differentiation stages (Bm1-5) of mature B cells within human tonsils did not place CD70-expressing B cells in one of these subsets. Functional experiments revealed that whereas both CD70- and CD70+ B cells can secrete immunoglobulin after activation with a combination of Staphylococcus aureus Cowan strain I and IL-2, only CD70+ B cells can produce large quantities of antibodies when stimulated in a T cell-dependent fashion. Our combined data imply that CD70 is a marker for mature B cells which have recently been primed by antigen in vivo.
authors.affiliation: Department of Clinical Viro-Immunology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam.
authors.forename: S M
authors.initials: SM
authors.lastname: Lens
authors.forename: R
authors.initials: R
authors.lastname: de Jong
authors.forename: B
authors.initials: B
authors.lastname: Hooibrink
authors.forename: G
authors.initials: G
authors.lastname: Koopman
authors.forename: S T
authors.initials: ST
authors.lastname: Pals
authors.forename: M H
authors.initials: MH
authors.lastname: van Oers
authors.forename: R A
authors.initials: RA
authors.lastname: van Lier
mesh_terms: D000917:Antibody Formation; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000145:classification* / Q000276:immunology / Q000378:metabolism*; D053282:CD27 Ligand; D002478:Cells, Cultured; D006801:Humans; D016130:Immunophenotyping; D008024:Ligands; D008211:Lymphocyte Cooperation; D008565:Membrane Proteins / Q000096:biosynthesis*; D014066:Palatine Tonsil / Q000276:immunology / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D053282:CD27 Ligand; C505771:CD70 protein, human; D008024:Ligands; D008565:Membrane Proteins