title: Monocyte-independent stimulation of human B lymphocytes by phorbol myristate acetate.
abstract: Phorbol myristate acetate (PMA) induces a low level of proliferation in purified human B lymphocytes when added in nanomolar concentrations to the culture medium. Much higher levels of thymidine incorporation, however, are obtained in the presence of other B cell stimuli such as anti-IgM antibodies or Staphylococcus aureus Cowan Strain 1 (SAC). The peak activity of PMA was observed on day 3 of B cell cultures containing either anti-IgM or SAC. The rigorous depletion of monocytes as well as add-back experiments indicate that the effect of PMA on anti-IgM-stimulated B cells is not mediated by the stimulation of accessory cells. Thus, PMA acts as a very potent mitogenic agent for human B cells under culture conditions that are commonly used to assess B cell growth factor activity.
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D004357:Drug Synergism; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D007700:Kinetics; D008213:Lymphocyte Activation / Q000187:drug effects*; D009000:Monocytes / Q000276:immunology* / Q000502:physiology; D010704:Phorbols / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007075:Immunoglobulin M; D010704:Phorbols; D013755:Tetradecanoylphorbol Acetate