title: B lymphoblasts show oxidase activity in response to cross-linking of surface IgM and HLA-DR.
abstract: Human B lymphocytes express components of the superoxide generating system of phagocytes, NADPH oxidase. We studied regulation of this 'B-cell oxidase' during in vitro blast transformation, using Lucigenin-amplified chemiluminescence (CL) to detect superoxide release. While freshly isolated tonsil B lymphocytes showed no CL responses, culture with phorbol myristate acetate (PMA) and ionomycin induced susceptibility to CL triggering by anti-IgM and anti-HLA-DR. Maximal effects were observed after 3 days of culture with 0.4 ng/ml PMA + 1 microgram/ml ionomycin. Cells from such B lymphoblast cultures showed no CL responses to opsonized zymosan. In contrast, peripheral blood mononuclear cells, where monocytes are the predominant oxidant source, showed CL responses to opsonized zymosan but not to anti-IgM and anti-HLA-DR, either before or after culture with PMA + ionomycin. Culture of B cells with the surface immunoglobulin cross-linking agent staphylococcus aureus Cowan I also led to emergence of a CL, response to anti-IgM, which was enhanced by interferon-gamma. Interestingly, markedly fewer B blasts than freshly isolated B lymphocytes expressed cytochrome b-558 surface antigen. Thus, the B-cell oxidase is up-regulated during blast transformation and can be triggered via surface IgM and HLA-DR; however, this appears to be restricted to a subset of B lymphoblasts.
authors.affiliation: Institute of Clinical Immunology, University of Bern, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Furukawa
authors.forename: R
authors.initials: R
authors.lastname: Tengler
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: A
authors.initials: A
authors.lastname: Urwyler
authors.forename: A L
authors.initials: AL
authors.lastname: de Weck
authors.forename: S
authors.initials: S
authors.lastname: Kanegasaki
authors.forename: F E
authors.initials: FE
authors.lastname: Maly
mesh_terms: D001402:B-Lymphocytes / Q000201:enzymology*; D003573:Cytochrome b Group / Q000096:biosynthesis; D003574:Cytochrome c Group / Q000378:metabolism; D004306:Dose-Response Relationship, Immunologic; D006684:HLA-DR Antigens / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology; D015759:Ionomycin; D007963:Leukocytes, Mononuclear; D008213:Lymphocyte Activation; D009247:NADH, NADPH Oxidoreductases / Q000096:biosynthesis*; D019255:NADPH Oxidases; D014066:Palatine Tonsil / Q000276:immunology; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate; D013997:Time Factors; D015854:Up-Regulation; D015054:Zymosan / Q000276:immunology
chemical_list: D003573:Cytochrome b Group; D003574:Cytochrome c Group; D006684:HLA-DR Antigens; D007075:Immunoglobulin M; D013481:Superoxides; D015759:Ionomycin; D007371:Interferon-gamma; D015054:Zymosan; C036888:cytochrome b558; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D013755:Tetradecanoylphorbol Acetate