title: Initiation in DNA synthesis by colony-stimulating factors in subsets of human CD34+ marrow cells.
abstract: Initiation of DNA synthesis by recombinant colony-stimulating factors (CSFs) was assessed in normal human marrow blast cells isolated by expression of CD34 antigen (tritiated thymidine incorporation). Continuous exposure to CSF was required. A mild increase in DNA synthesis was initiated by granulocyte CSF (G-CSF; greater than or equal to 1 ng/ml), to approximately 1.5 times control levels. A greater increase was initiated by granulocyte-macrophage CSF (GM-CSF), with a threshold of approximately 0.1 ng/ml and a plateau increment 2.5 times control levels. CD34+ cells were stimulated by interleukin 3 (IL-3) over a wide concentration range: two times control at 0.1/ml, three times control at 1 ng/ml, and four times control at 10 ng/ml. Overlap between responding populations was analyzed. G-CSF plus GM-CSF induced DNA synthesis greater than GM-CSF alone and supported the growth of much larger granulocyte-monocyte colonies. At saturating IL-3 concentrations, neither G-CSF nor GM-CSF induced additional DNA synthesis; at lower concentrations of IL-3, however, GM-CSF recruited additional cells into DNA synthesis. Using CD10 and CD19 antibodies to separate B-lineage cells, the CD34+ cells responding to CSF were observed to be in the non-B-lineage subset. Therefore 1) the response of CD34+ cell subsets CSFs is IL-3 greater than GM-CSF greater than G-CSF, and the IL-3-responsive population is heterogeneous for dose requirement; 2) a CD34+ subpopulation responding to concurrent G-CSF and GM-CSF includes increased proliferative potential cells; 3) IL-3-responsive cells include GM-CSF- and G-CSF-responsive cells, but cells responding to lower IL-3 concentration do not respond to GM-CSF; and 4) B-cell precursors do not respond to GM-CSF or IL-3 in this assay.
authors.affiliation: Oncology Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: L C
authors.initials: LC
authors.lastname: Strauss
authors.forename: S B
authors.initials: SB
authors.lastname: Welsh
authors.forename: C I
authors.initials: CI
authors.lastname: Civin
mesh_terms: D015703:Antigens, CD / Q000032:analysis*; D018941:Antigens, CD19; D018952:Antigens, CD34; D000943:Antigens, Differentiation / Q000032:analysis; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D000951:Antigens, Neoplasm / Q000032:analysis; D001854:Bone Marrow Cells; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D066298:In Vitro Techniques; D007377:Interleukin-3 / Q000494:pharmacology*; D015260:Neprilysin; D011994:Recombinant Proteins
chemical_list: D015703:Antigens, CD; D018941:Antigens, CD19; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; D000951:Antigens, Neoplasm; D007377:Interleukin-3; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D004247:DNA; D015260:Neprilysin