title: Binding of iodinated recombinant human GM-CSF to the blast cells of acute myeloblastic leukemia.
abstract: Granulocyte/macrophage-colony-stimulating factor (GM-CSF) is an effective growth factor for the blasts of acute myeloblastic leukemia (AML). Radioiodinated Chinese hamster ovary (CHO)-cell derived GM-CSF was prepared using Bolton-Hunter reagent to label free amino groups on the protein. Normal human neutrophils and the blast cells from AML patients were examined for binding. We found that there were fewer receptors of higher affinity on blast cells compared with neutrophils. After brief culture in suspension, receptor number increased and affinity decreased. Experiments provided evidence that GM-CSF from Escherichia coli had a higher affinity for neutrophils (kd = 20 pM) than the CHO-cell derived protein (kd = 500 pM-1 nM). This difference was reflected in the increased effectiveness of the E. coli protein over the CHO protein to stimulate colony formation in both normal bone marrow cells and AML blasts.
authors.affiliation: Ontario Cancer Institute, Toronto, Canada.
authors.forename: C A
authors.initials: CA
authors.lastname: Kelleher
authors.forename: G G
authors.initials: GG
authors.lastname: Wong
authors.forename: S C
authors.initials: SC
authors.lastname: Clark
authors.forename: P F
authors.initials: PF
authors.lastname: Schendel
authors.forename: M D
authors.initials: MD
authors.lastname: Minden
authors.forename: E A
authors.initials: EA
authors.lastname: McCulloch
mesh_terms: D003115:Colony-Stimulating Factors / Q000378:metabolism*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000378:metabolism*; D006801:Humans; D007457:Iodine Radioisotopes; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000032:analysis*; D016184:Receptors, Colony-Stimulating Factor; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D003115:Colony-Stimulating Factors; D006133:Growth Substances; D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D016184:Receptors, Colony-Stimulating Factor; D011994:Recombinant Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor