title: Platelet characteristic antigens of CD34+ cells in cryopreserved cord blood: a study of platelet-derived microparticles in transplant processing.
abstract: OBJECTIVE
  In previous studies, we found that platelet microparticles (PMPs) bind to cord blood (CB) CD34+ cells and transfer adhesion molecules to them, which enhances their engraftment. Before applying this phenomenon in actual transplants, we investigated the effect of PMPs on cryopreserved CD34+ cells in CB.
  
  
  METHODS
  We cryopreserved 18 CB units, then evaluated the binding of PMPs to CD34+ cells after thawing, by varying the expression of platelet characteristic antigens (CD41a, CD61, CD62P and CXCR4) on these cells. Adherence of the CD34+ cells, coated with freeze/thaw-induced PMPs, to endothelium and fibronectin was also studied, as were the effects of thrombin-induced PMPs from both fresh and preserved CB platelets.
  
  
  RESULTS
  PMPs induced by freezing and thawing adhered less well to CD34+ cells than did those from fresh CB, and cells coated with these PMPs had poor adherence. However, thrombin-induced PMPs from both fresh and preserved CB platelets bound equally well to cryopreserved CD34+ cells and improved their adhesion properties.
  
  
  CONCLUSIONS
  PMPs could be a useful tool for enhancing engraftment after CB transplantation.
authors.affiliation: Medical Experimental Centre, Guangzhou 12th People's Hospital, Guangzhou, China. binliu7@hotmail.com
authors.forename: B
authors.initials: B
authors.lastname: Liu
authors.forename: J S
authors.initials: JS
authors.lastname: Chen
authors.forename: M
authors.initials: M
authors.lastname: Cao
authors.forename: S L
authors.initials: SL
authors.lastname: Gu
authors.forename: C
authors.initials: C
authors.lastname: Liao
authors.forename: D Z
authors.initials: DZ
authors.lastname: Li
authors.forename: H Z
authors.initials: HZ
authors.lastname: Zhong
mesh_terms: D017304:Annexin A5 / Q000502:physiology; D018952:Antigens, CD34 / Q000032:analysis*; D001792:Blood Platelets / Q000737:chemistry*; D002452:Cell Count; D018925:Chemokines / Q000032:analysis; D015925:Cryopreservation; D004730:Endothelium, Vascular / Q000502:physiology; D005312:Fetal Blood / Q000166:cytology* / Q000637:transplantation*; D005353:Fibronectins / Q000502:physiology; D006085:Graft Survival / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques; D039661:Integrin beta3 / Q000032:analysis; D019007:P-Selectin / Q000032:analysis; D015539:Platelet Activation / Q000502:physiology; D010973:Platelet Adhesiveness / Q000502:physiology*; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000032:analysis; D013917:Thrombin / Q000502:physiology
chemical_list: D017304:Annexin A5; D018952:Antigens, CD34; D018925:Chemokines; D005353:Fibronectins; D039661:Integrin beta3; D019007:P-Selectin; D019038:Platelet Glycoprotein GPIb-IX Complex; D013917:Thrombin