Thrombopoiesis-stimulating factor: its effects on megakaryocyte colony formation in vitro and its relation to human granulocyte-macrophage colony-stimulating factor.
The effects of thrombopoiesis-stimulating factor (TSF) on human marrow megakaryocyte colony formation in vitro were studied by the plasma clot method. TSF was found to stimulate megakaryocyte as well as granulocyte-macrophage colony formation in vitro at optimal concentrations of 200-300 pg/ml of medium containing 2.5% horse serum. This colony-stimulating effect of TSF was not affected by polyclonal antibodies to human (h) interleukin 3 (IL-3) or to granulocyte colony-stimulating factor (G-CSF) but was neutralized by monoclonal or polyclonal antibodies to human granulocyte-macrophage colony-stimulating factor (hGM-CSF). In order to differentiate among cross-reactivity between TSF and hGM-CSF, induction of colony growth via release of GM-CSF, and presence of hGM-CSF in TSF preparations, TSF was tested on murine marrow cells, which are not responsive to hGM-CSF. TSF induced growth of murine megakaryocyte colony-forming units (CFU-MK) and granulocyte-macrophage colony-forming units (CFU-GM) in vitro with a dose response similar to that observed on human marrow cells; however, this effect could not be neutralized by antibodies to either human or murine GM-CSF. Using a double-antibody enzyme-linked immunosorbent assay, TSF preparations were found to contain 36 +/- 4 U of hGM-CSF per picogram of TSF protein. These findings indicate that hGM-CSF is responsible for the megakaryocyte colony-promoting effects of TSF on human marrow cells in vitro.
Department of Medicine, Veterans Administration Medical Center, Nashville, Tennessee 37212.
E N
EN
Dessypris
S
S
Chuncharunee
K E
KE
Frierson
D000818:Animals; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006023:Glycoproteins / Q000494:pharmacology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000494:pharmacology; D006410:Hematopoiesis / Q000187:drug effects*; D006801:Humans; D007158:Immunologic Techniques; D066298:In Vitro Techniques; D007377:Interleukin-3 / Q000494:pharmacology; D008533:Megakaryocytes / Q000502:physiology*; D051379:Mice; D013045:Species Specificity; D013926:Thrombopoietin / Q000494:pharmacology*
D003115:Colony-Stimulating Factors; D006023:Glycoproteins; D006133:Growth Substances; D007377:Interleukin-3; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D013926:Thrombopoietin