title: Comparisons of 12-tetradecanoylphorbol-13-acetate (TPA) and PHA as mitogens in the T-lymphocyte colony assay.
abstract: 12-O-tetradecanoylphorbol-13-acetate (TPA) has multiple effects on the capacity of human T-lymphocytes to form colonies in soft agar. This compound is directly mitogenic for T-lymphocytes; the optimal concentration (100 ng/ml) stimulates an average of 2862 +/- 583 colonies/7.5 X 10(5) cells plated. Furthermore, TPA can act synergistically with PHA to induce a greater number of colonies than can either mitogen alone. Sephadex G10 nonadherent (NA) cells can be directly stimulated by TPA; by contrast, these isolated T cells do not respond to PHA alone. These data indicate that the phorbol ester is able to provide an inductive signal for T cells, allowing them to respond to the plant lectin. Using T-cell subsets isolated by monoclonal antibodies and complement cytotoxicity, PHA is able to induce colony growth of T4 cells; T8 cells fail to respond unless cocultured with exogenous IL-2. TPA can directly stimulate colony formation by both subsets. In cultures stimulated with either TPA or PHA, approximately equal numbers of colonies are generated in the presence of IL-2, suggesting that T4 and T8 cells have similar proliferative capabilities. Phenotypic studies of cells contained in colonies showed differences between the two mitogens. With PHA, more than 98% are both T11 and T3 positive; by contrast, approximately one-third of the cells stimulated by TPA are T11 +, T3-.
mesh_terms: D002469:Cell Separation; D003114:Colony-Forming Units Assay; D003470:Culture Media; D004357:Drug Synergism; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D010641:Phenotype; D010835:Phytohemagglutinins / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D007376:Interleukin-2; D010835:Phytohemagglutinins; D013755:Tetradecanoylphorbol Acetate