title: [Study on the ex vivo expansion characteristics of umbilical cord blood CD34+ cells and mononuclear cells].
abstract: OBJECTIVE
  To explore the ex vivo expansion characteristics of selected CD(34)(+) cells and mononuclear cells (MNC).
  
  
  METHODS
  CD(34)(+) cells were isolated from umbilical cord blood MNC by MiniMACS system, expanded under the same conditions as that for MNC. The effects of re-isolation and the MNC supernatant (MNC-SN) on the selected CD(34)(+) cells were investigated. And the CD(34)(-) cells of MNC were cultured ex vivo.
  
  
  RESULTS
  In the culture of selected CD(34)(+) cells, both the colony density and the proportion of the CD(34)(+) cells declined continuously with the culturing, although they presented a high proliferation potential. However, in the culture of the MNC, from day 0 to day 7, the colony density and the proportion of CD(34)(+) cells were increased from 412 +/- 167/10(5) cells and (1.12 +/- 0.42)% to 1 162 +/- 566/10(5) cells and (4.17 +/- 1.44)%, respectively. It was found that both the total cells and the CD(34)(+) cells restored expansion potential by re-isolating. CD(34)(-) cells of MNC had the ability to form colony and could transform to CD(34)(+) cells. MNC-SN can promote colony forming ability and lead to CD(34)(+) cells differentiation at the same time.
  
  
  CONCLUSIONS
  In ex vivo culture, selected CD(34)(+) cells presented a high proliferation and differentiation potentials, and the CD(34)(-) cells produced during the cultivation had inhibition effect on CD(34)(+) cells expansion. CD(34)(-) cell population from cord blood MNC contained hematopoietic stem/progenitor cells and the cytokines secreted by CD(34)(-) cells could induce CD(34)(+) cells to more mature colony-forming cells.
authors.affiliation: The State Key Laboratory of Bioreactor Engineering, ECUST, Shanghai 200237, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Zi-zhen
authors.initials: ZZ
authors.lastname: Kang
authors.forename: Zhan-you
authors.initials: ZY
authors.lastname: Chi
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Wen-song
authors.initials: WS
authors.lastname: Tan
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis*; D002452:Cell Count; D002454:Cell Differentiation / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology*; D013997:Time Factors
chemical_list: D018952:Antigens, CD34