title: Demonstration of burst-promoting activity of recombinant human GM-CSF on circulating erythroid progenitors using an assay involving the delayed addition of erythropoietin.
abstract: We demonstrate through the use of an in vitro assay involving the delayed addition of erythropoietin that human recombinant GM-CSF, cloned from a mature T cell line, Mo, clearly has burst-promoting activity (BPA) on peripheral blood erythroid progenitors at picomolar concentrations. Delay for up to 72 hours of the addition of erythropoietin to semi-solid methylcellulose cultures of concentrated peripheral blood progenitors minimizes or eliminates BPA-independent erythroid colony formation with little loss of BPA-dependent erythroid colony formation. This assay will prove useful in accurately detecting sources of BPA.
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D004920:Erythropoiesis / Q000187:drug effects*; D004921:Erythropoietin / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000187:drug effects; D006801:Humans; D008722:Methods; D011994:Recombinant Proteins / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D003115:Colony-Stimulating Factors; D011994:Recombinant Proteins; D004921:Erythropoietin