title: Comparison of the biological activity of two sources of colony-stimulating factor (CSF).
abstract: Two possible standard sources of colony-stimulating factor (CSF) have been available commercially; one is GCT-conditioned medium (GCT-CM) and the other is T3M-5A-CSF. To clarify their biological activity and determine whether they can provide a stimulus identical with leukocyte feeders, the number and the morphology of colonies stimulated by them were compared. A dose-response study and a mixing experiment between them suggested the presence of inhibitor(s) in GCT-CM but not in T3M-5A-CSF. Both types of CSF stimulated mainly granulocytic colonies at day 7. T3M-5A-CSF caused a dose-dependent increase in macrophagic colonies at day 14. The number of colonies stimulated by GCT-CM and T3M-5A-CSF did not differ from that of leukocyte feeders, but the morphology of colonies differed significantly. These results indicate that there is a qualitative difference in the effect of GCT-CM and T3M-5A-CSF on human bone marrow cells, and that they do not supply a stimulus identical with leukocyte feeders. Though GCT-CM and T3M-5A-CSF are expected to serve as useful tools in the standard CFU-C assay, we should observe their characteristics and accumulate more information about their behavior on normal as well as on patient bone marrow cells.
mesh_terms: D001853:Bone Marrow / Q000502:physiology*; D002478:Cells, Cultured; D002999:Clone Cells; D003115:Colony-Stimulating Factors / Q000302:isolation & purification / Q000494:pharmacology*; D003470:Culture Media; D046508:Culture Techniques / Q000379:methods; D006801:Humans; D007700:Kinetics; D007962:Leukocytes / Q000502:physiology
chemical_list: D003115:Colony-Stimulating Factors; D003470:Culture Media