title: LPF-induced T cell colony formation: effect of PMA and interleukin-2, and surface marker analysis.
abstract: We demonstrated that a primary exposure to the lymphocytosis promoting factor (LPF) of Bordetella pertussis-induced T cell colony formation. Colony formation was observed when mononuclear cells (MNC) were cultured at concentrations of more than 1 X 10(6)/ml, and reached a peak on day 8. However, the number of colonies generated with LPF was about one-third induced with phytohaemagglutinin (PHA). Removal of monocytes from MNC or T cells resulted in the failure of colony formation, but colony growth could be restored by the addition of monocytes or B enriched cells, indicating that they were required for the optimal colony growth induced by LPF. In the absence of accessory cells, optimal colony growth from monocyte depleted T cells could be obtained when an appropriate concentration of phorbol myristate acetate (PMA) or interleukin-2 (IL-2) was added in the cultures with LPF. PMA did not enhance LPF-induced colony formation in the cultures containing a sufficient amount of exogeneous IL-2. These findings suggest that IL-2 is essential to LPF-induced colony formation. Surface marker analysis showed that most of LPF-induced colony cells were T cells. The percentages of T4+ and T gamma cells of LPF-induced colony cells were more, and T8+ cells less, than those of PHA-induced colony cells. Ia1, T9 and Tac antigens were detected on many colony cells induced by LPF or PHA. These results indicate that the phenotype of LPF-induced colony cells differs from those of PHA, but the sequential antigen expression on lymphocytes triggered by IL-2 might be similar in both LPF- and PHA-induced colony formation.
mesh_terms: D000954:Antigens, Surface / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology; D001427:Bacterial Toxins / Q000494:pharmacology*; D002999:Clone Cells / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000276:immunology* / Q000494:pharmacology*; D007958:Leukocyte Count; D009000:Monocytes / Q000276:immunology; D037342:Pertussis Toxin; D010641:Phenotype; D010704:Phorbols / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D010566:Virulence Factors, Bordetella
chemical_list: D000954:Antigens, Surface; D001427:Bacterial Toxins; D007376:Interleukin-2; D010704:Phorbols; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D013755:Tetradecanoylphorbol Acetate