title: DNA-synthetic responses of fractionated human lymphocytes exposed to lymphocyte-derived mitogenic factor.
abstract: Human peripheral lymphocytes that have been exposed to phytohemagglutinin (PHA) release mitogenic factors (MF) on subsequent incubation in fresh medium. In this investigation, MF-rich supernatants were analyzed for their ability to induce DNA synthesis in various fractions of peripheral human lymphocytes. MF was found to induce higher DNA synthesis in T-cell preparations that in unfractionated lymphoid preparations or B-cell-rich fractions. Evidence is presented showing that some types of non-T-cell can inhibit the MF response of T cells. These cells are nonadherent and nonphagocytic and require DNA synthesis to express their inhibitory activity. These results suggest that the regulation of the action of lymphocyte-derived MF is cell-mediated.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D006801:Humans; D037102:Lectins / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000276:immunology* / Q000378:metabolism; D008934:Mitogens / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D037102:Lectins; D008934:Mitogens; D004247:DNA