title: [In vitro expansion of cord blood megakaryocyte progenitor].
abstract: OBJECTIVE
  To expand cord blood megakaryocyte progenitor cells in vitro.
  
  
  METHODS
  Cord blood CD34+ cells were selected by magnetic cell sorting (MACS), and thrombopoietin (TPO), interleukin-11 (IL-11), and heparin were used in the expansion system of megakaryocyte progenitor. The expansion efficiency was measured by fluorescence-activated cell sorting (FACS) using the megakaryocytic specific monoclonal antibodies (CD34+, CD41a+, CD61+, CD34+CD41a+, CD41a+CD61+) and colony-forming units-megakaryocyte (CFU-MK) analysis. The expanded megakaryocyte progenitor were determined by histochemistry staining using CD41a and the observation of the ultrastructure of megakaryocyte (MK) by electron microscopy. The megakaryocyte function were examined by the platelet activation in vitro and nonobese diabetic/severe combined immunodifficiency (NOD/SCID) mice transplantation in vivo.
  
  
  RESULTS
  CD34+CD41a+ cells was expanded (4.0 +/- 1.7) folds on day 7 in TPO (50 ng/ml) group and (10.5 +/- 4.8) fold in TPO combined with IL-11 group; after heparin was joined in on day 0, a more significantly elevated expansion was found in the heparin, TPO, and IL-11 group [(29.9 +/- 6.4) folds than the above two groups; P < 0.05]. Meanwhile, the large CFU-MK colony (> 50 cells/colony) was (106.8 +/- 26.9) folds on day 7 (P < 0.05). The megakaryocyte expanding with TPO, IL-11 and heparin for 7 days in vitro transplanted the NOD/SCID mice fasten the recovery of platelet and white blood cell account and improved the survival. Megakaryocyte under culture displayed certain development of territories membrane. Platelet activation test comfirmed that the expanding megakaryocyte progenitor had the normal function.
  
  
  CONCLUSIONS
  TPO, IL-11, and heparin combination system for ex vivo expansion is an effective expansion system of megakaryocyte progenitor.
authors.affiliation: National Key Laboratory of Experimental Hematology, Institute of Hematology, CAMS and PUMC, Tianjin 300020, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Feng
authors.forename: Zhi-jian
authors.initials: ZJ
authors.lastname: Xiao
authors.forename: Shi-cai
authors.initials: SC
authors.lastname: Xu
authors.forename: Shi-hong
authors.initials: SH
authors.lastname: Lu
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Jin-hua
authors.initials: JH
authors.lastname: Liu
authors.forename: Zhong-chao
authors.initials: ZC
authors.lastname: Han
mesh_terms: D000818:Animals; D018952:Antigens, CD34; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D017370:Interleukin-11 / Q000494:pharmacology; D008297:Male; D008533:Megakaryocytes / Q000166:cytology* / Q000276:immunology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D013926:Thrombopoietin / Q000494:pharmacology
chemical_list: D018952:Antigens, CD34; D017370:Interleukin-11; D006493:Heparin; D013926:Thrombopoietin