title: Generation of CFU-c suppressor T cells in vitro. IV. effect of time on the inhibitory activity of mitogen-primed normal T lymphocytes.
abstract: Bone marrow and peripheral blood T cells were obtained from 15 normal individuals by E rosetting and cultured in round-bottomed microwells for 7 days in RPMI or in RPMI supplemented with mitogens (pokeweed mitogen, phytohemagglutinin or concanavalin A). Supernatants and cells were harvested on days 1, 2, 3, 4 and 7 and co-cultured with normal marrow cells in semi-solid agar to test their CFU-c suppressor activity. The results of this study indicate that (a) RPMI treated cells and their supernatants have no effect or an enhancing effect on CFU-c growth; (b) all 3 mitogens generate CFU-c suppressor T cells on day 1 of culture; (c) the inhibitory activity is detectable until day 4 of culture, though overall reduced, and is completely lost on day; 7 (d) the trend for supernatants of mitogen-treated T cells is quite similar with a tendency to complete loss of the inhibitory effect on day 7. We interpret these data as indicating that T cells release a soluble inhibitor of CFU-c growth within a few hours from polyclonal activation, the production of which is either controlled or lost with time in culture.
mesh_terms: D000741:Anemia, Aplastic / Q000097:blood / Q000276:immunology; D001854:Bone Marrow Cells; D002470:Cell Survival; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003208:Concanavalin A / Q000494:pharmacology; D006410:Hematopoiesis; D006801:Humans; D008213:Lymphocyte Activation; D008934:Mitogens / Q000494:pharmacology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000145:classification / Q000166:cytology / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000276:immunology
chemical_list: D008934:Mitogens; D010835:Phytohemagglutinins; D003208:Concanavalin A