title: Functional analysis of initial cell divisions defines the subsequent fate of individual human CD34(+)CD38(-) cells.
abstract: OBJECTIVE
  We assessed the relationship of individual cell divisional behavior with the functional fate of stem cell candidates at the single cell level.
  
  
  METHODS
  Individual CD34(+)CD38(-) cells derived from cord blood (88-352 cells in each of 25 experiments) were cultured in early-acting conditioned medium (EACM) or late-acting proliferation medium (LAPM). The initial cell divisions were microscopically monitored every 12 to 24 hours and then assessed for primitive function in the myeloid lymphoid-initiating cell assay and committed function in the colony-forming cell (CFC) assay.
  
  
  RESULTS
  Despite a higher proliferative capacity in LAPM, significantly more quiescent cells (11.1 +/- 1.7%) were found in LAPM than in EACM cultures (1.1 +/- 0.4%; p < 0.001). No differences were observed in the initially plated CD34(+)Cd38(-) cells that produced asymmetrically dividing progeny. The majority of cells with subsequent ML-IC function divided in EACM but were found among quiescent cells in LAPM conditions. All cycling cells with subsequent ML-IC capacity initially remained quiescent for at least 96 hours. All ML-IC had been recruited exclusively (100%) from either cytokine nonresponsive (quiescent) or slow and asymmetrically dividing cells (1-2 divisions). In contrast, the majority of CFCs entered the cell cycle immediately after plating, have divided more than two times, and only 20.2 +/- 5.5% of the cycled CFC divided asymmetrically.
  
  
  CONCLUSIONS
  Asymmetric divisional behavior of CD34(+)CD38(-)cells cannot be influenced by culture conditions. Primitive ML-IC can be distinguished from committed CFC by initial quiescence or asymmetric divisions. Committed CFC cycle rapidly and symmetrically.
authors.affiliation: Department of Medicine V, University of Heidelberg, Heidelberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Punzel
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.forename: Daihong
authors.initials: D
authors.lastname: Liu
authors.forename: Volker
authors.initials: V
authors.lastname: Eckstein
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Ho
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis*; D000943:Antigens, Differentiation / Q000032:analysis*; D002455:Cell Division / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D016207:Cytokines / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007231:Infant, Newborn; D007700:Kinetics; D008562:Membrane Glycoproteins; D009244:NAD+ Nucleosidase / Q000032:analysis* / Q000172:deficiency
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D017077:Culture Media, Conditioned; D016207:Cytokines; D008562:Membrane Glycoproteins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D009244:NAD+ Nucleosidase; D051997:ADP-ribosyl Cyclase 1