title: Erythroid burst-promoting activity of purified recombinant human GM-CSF and interleukin-3: studies with anti-GM-CSF and anti-IL-3 sera and studies in serum-free cultures.
abstract: We studied the erythroid burst-promoting activity (BPA) of recombinant human granulocyte/macrophage colony-stimulating factor (GM-CSF) and Interleukin-3 (IL-3) with two experimental approaches. First we studied the effects of polyclonal antisera prepared against human GM-CSF and gibbon IL-3 on colony formation from 1,000 bone marrow null cells/dish in serum-containing culture. Both GM-CSF and IL-3 independently enhanced erythroid burst formation; however, IL-3 showed more BPA activity than GM-CSF. These data are in agreement with an emerging view that the primary targets of IL-3 are primitive progenitors and that the targets of GM-CSF are intermediate progenitors, including erythroid burst-forming units (BFU-E). The proliferation of one population of BFU-E was independent of GM-CSF or IL-3. To characterize this population of BFU-E further, we developed a serum-free culture assay for the purified progenitors by incorporating insulin-like growth factor-1 (IGF-1) to the serum-free medium. The development of erythroid bursts was supported by IL-3, IGF-1, and erythropoietin (Ep) in a serum-free culture system and to a lesser extent by the combination of GM-CSF, IGF-1, and Ep. Although the burst-promoting ability of GM-CSF and IL-3 was again demonstrated in this system, unlike serum-containing culture Ep alone did not support burst formation. These results indicate that when fetal calf serum (FCS) is present, the culture system contains BPA that is not GM-CSF or IL-3.
mesh_terms: D000328:Adult; D000818:Animals; D001790:Blood Physiological Phenomena; D003114:Colony-Forming Units Assay; D003115:Colony-Stimulating Factors / Q000276:immunology / Q000494:pharmacology*; D006224:Cricetinae; D003470:Culture Media / Q000032:analysis; D004920:Erythropoiesis / Q000187:drug effects; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000276:immunology / Q000494:pharmacology*; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology*; D007377:Interleukin-3 / Q000276:immunology / Q000494:pharmacology*; D008222:Lymphokines / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D019714:Tissue Inhibitor of Metalloproteinases
chemical_list: D003115:Colony-Stimulating Factors; D003470:Culture Media; D006133:Growth Substances; D007106:Immune Sera; D007377:Interleukin-3; D008222:Lymphokines; D011994:Recombinant Proteins; D019714:Tissue Inhibitor of Metalloproteinases; D016178:Granulocyte-Macrophage Colony-Stimulating Factor