title: Modulation of in vitro proliferation kinetics and primitive hematopoietic potential of individual human CD34+CD38-/lo cells in G0.
abstract: Whether cytokines can modulate the fate of primitive hematopoietic progenitor cells (HPCs) through successive in vitro cell divisions has not been established. Single human marrow CD34+CD38-/lo cells in the G0 phase of cell cycle were cultured under 7 different cytokine combinations, monitored for proliferation on days 3, 5, and 7, then assayed for long-term culture-initiating cell (LTC-IC) function on day 7. LTC-IC function was then retrospectively correlated with prior number of in vitro cell divisions to determine whether maintenance of LTC-IC function after in vitro cell division is dependent on cytokine exposure. In the presence of proliferation progression signals, initial cell division was independent of cytokine stimulation, suggesting that entry of primitive HPCs into the cell cycle is a stochastic property. However, kinetics of proliferation beyond day 3 and maintenance of LTC-IC function were sensitive to cytokine stimulation, such that LTC-IC underwent an initial long cell cycle, followed by more synchronized shorter cycles varying in length depending on the cytokine combination. Nonobese diabetic/severe combined immunodeficiency (NOD/SCID) transplantation studies revealed analogous results to those obtained with LTC-ICs. These data suggest that although exit from quiescence and commitment to proliferation might be stochastic, kinetics of proliferation, and possibly fate of primitive HPCs, might be modulated by extrinsic factors.
authors.affiliation: Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA. esrour@iupui.edu
authors.forename: Edward F
authors.initials: EF
authors.lastname: Srour
authors.forename: Xia
authors.initials: X
authors.lastname: Tong
authors.forename: Ki Woong
authors.initials: KW
authors.lastname: Sung
authors.forename: P Artur
authors.initials: PA
authors.lastname: Plett
authors.forename: Susan
authors.initials: S
authors.lastname: Rice
authors.forename: Joanne
authors.initials: J
authors.lastname: Daggy
authors.forename: Constantin T
authors.initials: CT
authors.lastname: Yiannoutsos
authors.forename: Rafat
authors.initials: R
authors.lastname: Abonour
authors.forename: Christie M
authors.initials: CM
authors.lastname: Orschell
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000378:metabolism; D051997:ADP-ribosyl Cyclase 1; D000328:Adult; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008562:Membrane Glycoproteins; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D016192:Resting Phase, Cell Cycle / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D016207:Cytokines; D008562:Membrane Glycoproteins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; C498155:Cd38 protein, mouse; D051997:ADP-ribosyl Cyclase 1