title: Individual and synergistic cytokine effects controlling the expansion of cord blood CD34(+) cells and megakaryocyte progenitors in culture.
abstract: OBJECTIVE
  Expansion of hematopoietic progenitors ex vivo is currently investigated as a means of reducing cytopenia following stem cell transplantation. The principal objective of this study was to develop a new cytokine cocktail that would maximize the expansion of megakaryocyte (Mk) progenitors that could be used to reduce periods of thrombocytopenia.
  
  
  METHODS
  We measured the individual and synergistic effects of six cytokines [stem cell factor (SCF), FLT-3 ligand (FL), interleukin (IL)-3, IL-6, IL-9 and IL-11] commonly used to expand cord blood (CB) CD34(+) cells on the expansion of CB Mk progenitors and major myeloid populations by factorial design.
  
  
  RESULTS
  These results revealed an elaborate array of cytokine individual effects complemented by a large number of synergistic and antagonistic interaction effects. Notably, strong interactions with SCF were observed with most cytokines and its concentration level was the most influential factor for the expansion and differentiation kinetics of CB CD34(+) cells. A response surface methodology was then applied to optimize the concentrations of the selected cytokines. The newly developed cocktail composed of SCF, thrombopoietin (TPO) and FL increased the expansion of Mk progenitors and maintained efficient expansion of clonogenic progenitors and CD34(+) cells. CB cells expanded with the new cocktail were shown to provide good short- and long-term human platelet recovery and lymphomyeloid reconstitution in NOD/SCID mice.
  
  
  CONCLUSIONS
  Collectively, these results define a complex cytokine network that regulates the growth and differentiation of immature and committed hematopoietic cells in culture, and confirm that cytokine interactions have major influences on the fate of hematopoietic cells.
authors.affiliation: Héma-Québec, Département de Recherche et Développement, Québec City, PQ, Canada. nicolas.pineault@hema-quebec.qc.ca
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pineault
authors.forename: Valérie
authors.initials: V
authors.lastname: Cortin
authors.forename: Lucie
authors.initials: L
authors.lastname: Boyer
authors.forename: Alain
authors.initials: A
authors.lastname: Garnier
authors.forename: Amélie
authors.initials: A
authors.lastname: Robert
authors.forename: Cynthia
authors.initials: C
authors.lastname: Thérien
authors.forename: Denis-Claude
authors.initials: DC
authors.lastname: Roy
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism*; D016207:Cytokines / Q000494:pharmacology*; D004357:Drug Synergism; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D006801:Humans; D017370:Interleukin-11 / Q000494:pharmacology; D007377:Interleukin-3 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D016906:Interleukin-9 / Q000494:pharmacology; D055016:Megakaryocyte Progenitor Cells / Q000166:cytology* / Q000187:drug effects*; D008565:Membrane Proteins / Q000494:pharmacology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D019089:Stem Cell Factor / Q000494:pharmacology
chemical_list: D018952:Antigens, CD34; D016207:Cytokines; D017370:Interleukin-11; D007377:Interleukin-3; D015850:Interleukin-6; D016906:Interleukin-9; D008565:Membrane Proteins; D019089:Stem Cell Factor; C084881:flt3 ligand protein