title: Monocyte-conditioned medium and interleukin 1 induce granulocyte-macrophage colony-stimulating factor production in the adherent cell layer of murine bone marrow cultures.
abstract: We have studied how production of colony-stimulating factors (CSF) can be induced in murine long-term bone marrow cultures (LTBMC). We found that the adherent cells, but not the nonadherent cells, of LTBMC synthesized and secreted large amounts of CSF upon stimulation with monocyte-conditioned medium (MCM) from the early phase of monocyte culturing. This CSF induced both granulocyte- and macrophage-containing colonies. Interleukin 1 (IL-1) also induced CSF production by the adherent cells, although not to the same extent as MCM. Medium conditioned by E-rosette-positive lymphocytes could not substitute for MCM. CSF production varied in long-term bone marrow cultures less than two weeks old, but thereafter the amount of CSF obtained was relatively independent of the age of the cultures (2-26 weeks). No correlation was found between the content of granulocyte-macrophage colony-forming cells (GM-CFC) in the nonadherent cell fraction of LTBMC and the ability of the adherent cell layer to produce CSF. These results suggest a two-stage process for CSF synthesis. Monocytes produce a factor(s) that, in a second step, leads to bioassayable levels of CSF in the supernatant of adherent cells in LTBMC.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000187:drug effects / Q000378:metabolism; D001854:Bone Marrow Cells; D002448:Cell Adhesion; D002452:Cell Count; D003115:Colony-Stimulating Factors / Q000096:biosynthesis*; D003470:Culture Media; D003513:Cycloheximide / Q000494:pharmacology; D006098:Granulocytes / Q000166:cytology* / Q000378:metabolism; D007375:Interleukin-1 / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D009000:Monocytes / Q000378:metabolism*; D013997:Time Factors
chemical_list: D003115:Colony-Stimulating Factors; D003470:Culture Media; D007375:Interleukin-1; D003513:Cycloheximide