title: Activation of human B lymphocytes by 8' substituted guanosine derivatives.
abstract: The 8-substituted guanosine derivatives (8-sGs), mercaptoguanosine and bromoguanosine, are shown to induce immunoglobulin production and proliferation in a subset of normal human B lymphocytes. Limiting dilution analysis indicated that the 8-sG-responsive B cell pool is approximately 10 times larger than that activated by pokeweed mitogen (PWM), 10 times smaller than that activated by Epstein-Barr virus (EBV), and contains approximately equal proportions of cells committed to the expression of IgG, IgA or IgM isotypes. Although some B cells seem able to respond to 8-sGs in the absence of T helper cells, maximal immunoglobulin production is only observed in the presence of T cells. The 8-sG response pattern of human B lymphocytes appeared similar but not identical to that reported for rodent cells. The mitogenic 8-sGs are unique activators as they bypass surface membrane interactions obligatory for other agents including anti-IgM, Staphylococcus aureus particles, PWM, and EBV.
authors.affiliation: Hospital for Sick Children, Department of Paediatrics, Toronto, Ontario, Canada.
authors.forename: H M
authors.initials: HM
authors.lastname: Dosch
authors.forename: V
authors.initials: V
authors.lastname: Osundwa
authors.forename: P
authors.initials: P
authors.lastname: Lam
mesh_terms: D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D006151:Guanosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004854:Herpesvirus 4, Human / Q000276:immunology; D006801:Humans; D007132:Immunoglobulin Isotypes / Q000096:biosynthesis; D066298:In Vitro Techniques; D008213:Lymphocyte Activation / Q000187:drug effects*; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology; D013872:Thionucleosides / Q000494:pharmacology
chemical_list: D007132:Immunoglobulin Isotypes; D011043:Pokeweed Mitogens; D013872:Thionucleosides; D006151:Guanosine; C035169:8-bromoguanosine; C037031:8-thioguanosine