title: Interleukin-9 stimulates the proliferation of enriched human erythroid progenitor cells: additive effect with GM-CSF.
abstract: In the study we report here we investigated the colony-stimulating activities of interleukin-9 (IL-9). In the presence of erythropoietin, IL-9 was found to stimulate the proliferation of relatively early erythroid progenitor cells (BFU-E) from normal human bone marrow cells depleted of mononuclear phagocytes and T lymphocytes. Neutralization experiments demonstrated that the observed BFU-E-stimulating effect was not the result of intermediate production of IL-3 or GM-CSF by residual accessory cells in response to IL-9. Accordingly, the effects of IL-9 were preserved when cell suspensions were further depleted of accessory cells using CD34 enrichment of progenitor cells. Furthermore, IL-9 did not stimulate bone marrow mononuclear cells to express mRNA for IL-3, GM-CSF, EPA (erythroid-promoting activity), or IL-4, as determined by a cDNA-PCR method. IL-9 is likely to act on a subpopulation of IL-3-responsive erythroid progenitor cells that are not stimulated by GM-CSF, since plateau concentration of IL-9 and GM-CSF had additive effects on BFU-E formation, whereas a combination of IL-9 and IL-3 did not. In addition to its burst-promoting activity, IL-9 was found to have a modest stimulatory activity on myeloid progenitor cells (CFU-GM) in some experiments, suggesting that this effect may be donor related.
authors.affiliation: Department of Hematology, University Medical Center, Leiden, The Netherlands.
authors.forename: M R
authors.initials: MR
authors.lastname: Schaafsma
authors.forename: J H
authors.initials: JH
authors.lastname: Falkenburg
authors.forename: N
authors.initials: N
authors.lastname: Duinkerken
authors.forename: J
authors.initials: J
authors.lastname: Van Snick
authors.forename: J E
authors.initials: JE
authors.lastname: Landegent
authors.forename: R
authors.initials: R
authors.lastname: Willemze
authors.forename: W E
authors.initials: WE
authors.lastname: Fibbe
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D004357:Drug Synergism; D015672:Erythroid Precursor Cells / Q000166:cytology*; D004921:Erythropoietin / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D016906:Interleukin-9 / Q000494:pharmacology*; D051379:Mice; D011994:Recombinant Proteins / Q000494:pharmacology; D013268:Stimulation, Chemical
chemical_list: D016906:Interleukin-9; D011994:Recombinant Proteins; D004921:Erythropoietin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor