title: Recombinant murine granulocyte macrophage colony-stimulating factor has megakaryocyte colony-stimulating activity and augments megakaryocyte colony stimulation by interleukin 3.
abstract: Recombinant murine granulocyte macrophage colony-stimulating factor (rGM-CSF) has been produced in Escherichia coli and purified to homogeneity. GM-CSF has an established role as an in vitro regulator of granulocyte and macrophage colony formation. We have determined that rGM-CSF also has intrinsic activity as a megakaryocyte colony-stimulating factor and that rGM-CSF augments the effect of interleukin 3 (IL-3) on megakaryocyte colony formation. The dose-response curve for megakaryocyte colony induction with rGM-CSF showed plateau megakaryocyte stimulation at 9 ng/ml. When IL-3 (at a plateau dose for megakaryocyte colony induction) was added to rGM-CSF over a 0-22-ng/ml dose range, the resultant megakaryocyte colony stimulation approximated the sum of the levels of stimulation produced by either factor alone. These results establish GM-CSF as a multilineage growth factor with definite megakaryocyte colony-stimulating activity and indicate that both GM-CSF and IL-3 are important in the regulation of megakaryocytopoiesis.
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D003114:Colony-Forming Units Assay; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D004357:Drug Synergism; D005260:Female; D006098:Granulocytes; D006410:Hematopoiesis / Q000187:drug effects*; D006412:Hematopoietic Stem Cells / Q000187:drug effects*; D007377:Interleukin-3 / Q000494:pharmacology*; D008264:Macrophages; D008533:Megakaryocytes / Q000166:cytology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000494:pharmacology
chemical_list: D003115:Colony-Stimulating Factors; D007377:Interleukin-3; D011994:Recombinant Proteins