Exclusive expression of G-CSF receptor on myeloid progenitors in bone marrow CD34+ cells.
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.
Ebihara
Y
Y
Department of Clinical Oncology, The Institute of Medical Science, The University of Tokyo, Japan.
Xu
M J
MJ
Manabe
A
A
Kikuchi
A
A
Tanaka
R
R
Kato
S
S
Nakahata
T
T
Tsuji
K
K
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*
D018952:Antigens, CD34; D016188:Receptors, Granulocyte Colony-Stimulating Factor