title: Mitogenic activity elaborated by macrophage-like cell lines acts as competence factor(s) for BALB/c 3T3 cells.
abstract: The culture medium from several murine macrophage-like cell lines contained a mitogenic activity that functioned synergistically with platelet-poor plasma to induce DNA synthesis in quiescent density-inhibited BALB/c 3T3 fibroblasts. This mitogenic activity was generated by P388D1 (and other established lines of) macrophage-like cells that were cultured either in medium alone or in medium supplemented with platelet-poor plasma. The amount of mitogenic activity produced was directly related to the length of time the macrophage-like cells were maintained in the medium. Serum-free medium conditioned by macrophage-cells did not stimulate DNA synthesis in density-inhibited 3T3 cells in the absence of plasma; however, a transient (4-hr) exposure to serum-free macrophage-conditioned medium allowed quiescent cells to respond to plasma-derived progression factors. The addition of plasma to 3T3 cells that had been treated with the macrophage-conditioned medium brought about DNA synthesis after a 12-hr lag. The mitogenic activity that was in macrophage-conditioned medium bound to DEAE-Sephadex and eluted in a single peak using a linear NaCl gradient. This macrophage-derived competence factor was not mitogenic for lymphocytes and was clearly separated by DEAE-Sephadex chromatography from the major peak of the previously described mitogenic monokine, Interleukin-1 (lymphocyte activating factor).
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004261:DNA Replication / Q000187:drug effects; D005347:Fibroblasts / Q000502:physiology; D006133:Growth Substances / Q000302:isolation & purification; D007700:Kinetics; D008264:Macrophages / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008934:Mitogens / Q000302:isolation & purification / Q000494:pharmacology; D010455:Peptides / Q000302:isolation & purification; D010982:Platelet-Derived Growth Factor; D011506:Proteins / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D006133:Growth Substances; D008934:Mitogens; D010455:Peptides; D010982:Platelet-Derived Growth Factor; D011506:Proteins