title: Exclusive expression of G-CSF receptor on myeloid progenitors in bone marrow CD34+ cells.
abstract: Although granulocyte colony-stimulating factor (G-CSF) has been reported to act on cells of neutrophilic lineage, the administration of G-CSF to induce the mobilization of various haematopoietic progenitors into the circulation. We analysed the expression of receptors for G-CSF (G-CSFR) on human bone marrow and G-CSF-mobilized peripheral blood CD34+ cells, and examined the proliferation and differentiation capabilities of sorted CD34+G-CSFR+ and CD34+G-CSFR- cells using methylcellulose clonal culture. Flow cytometric analysis showed that G-CSFR was expressed on 14.9 +/- 4.9% of bone marrow CD34+ cells, most of which were included in CD34+CD33+ and CD34+CD38+ cell fractions. In clonal cultures, CD34+G-CSFR+ cells produced only myeloid colonies, whereas CD34+G-CSFR- cells produced erythroid bursts, megakaryocyte and multilineage colonies. When incubated with the cytokine cocktail for 5 d, CD34+G-CSFR- cells generated CD34+G-CSFR+ myeloid progenitors. In G-CSF-mobilized peripheral blood, CD34+ cells contained 10.8 +/- 5.8% of G-CSFR+ cells, most of which were also myeloid progenitors, although CD34+G-CSFR- cells contained a substantial number of myeloid progenitors. These results indicated that the expression of G-CSFR on CD34+ cells is restricted to myeloid progenitors, suggesting that the specific activity of G-CSF on myelopoiesis depends on the exclusive expression of its receptor on myeloid progenitors, and that the mobilization of various haematopoietic progenitors is not a direct effect of G-CSF in humans.
authors.affiliation: Department of Clinical Oncology, The Institute of Medical Science, The University of Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ebihara
authors.forename: M J
authors.initials: MJ
authors.lastname: Xu
authors.forename: A
authors.initials: A
authors.lastname: Manabe
authors.forename: A
authors.initials: A
authors.lastname: Kikuchi
authors.forename: R
authors.initials: R
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Nakahata
authors.forename: K
authors.initials: K
authors.lastname: Tsuji
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000276:immunology*; D001854:Bone Marrow Cells / Q000276:immunology* / Q000378:metabolism*; D002452:Cell Count; D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D005434:Flow Cytometry / Q000379:methods; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D006801:Humans; D016188:Receptors, Granulocyte Colony-Stimulating Factor / Q000378:metabolism*
chemical_list: D018952:Antigens, CD34; D016188:Receptors, Granulocyte Colony-Stimulating Factor