Mouse peritoneal macrophages produce CFU-gm and CFU-meg growth-promoting factors.
The effect of peritoneal macrophage-conditioned medium (macrophage CM) from lipopolysaccharide-injected mice on granulocyte-macrophage colony (CFU-gm) and megakaryocyte colony (CFU-meg) formation was examined using a plasma clot culture system. Macrophage CM stimulated mouse bone marrow cells to form CFU-gm and CFU-meg in the presence of pokeweed mitogen-stimulated spleen cell-conditioned medium, but it had no effect on colony formation in the absence of exogenous colony-stimulating factors (CSF). CFU-gm and CFU-meg colony formation was enhanced by low concentrations of exogenous GM-CSF or Meg-CSF alone. These data demonstrate that macrophage CM contains an activity that sensitized CFU-gm and CFU-meg to exogenous CSF.
D000818:Animals; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003115:Colony-Stimulating Factors / Q000096:biosynthesis* / Q000494:pharmacology; D003470:Culture Media / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006098:Granulocytes / Q000166:cytology*; D006133:Growth Substances / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism*; D008533:Megakaryocytes / Q000166:cytology*; D051379:Mice; D008815:Mice, Inbred Strains; D010529:Peritoneal Cavity / Q000166:cytology; D013154:Spleen / Q000166:cytology; D013234:Stem Cells / Q000166:cytology*
D003115:Colony-Stimulating Factors; D003470:Culture Media; D006133:Growth Substances; D008070:Lipopolysaccharides; D016178:Granulocyte-Macrophage Colony-Stimulating Factor