title: [Effect of endothelial cell-targeted soluble Notch ligand hD1R protein on expansion and engraftment of cord blood hematopoietic stem/progenitor cells].
abstract: OBJECTIVE
  To evaluate the effects of endothelial cell- targeted soluble Notch ligand hD1R protein on expansion and engraftment of cord blood hematopoietic stem/progenitor cell (CB HSPCs).
  
  
  METHODS
  Recombinant hD1R protein was first induced and purified. Human cord blood CD34⁺ cells were co-cultured on human umbilical vein endothelial cells (HUVECs) supplemented with a cocktail containing 5 types of human cytokines including TPO, SCF, FL, IL-6, IL-3 (5GF) and soluble hD1R. The expansion of CD34⁺ cells was tested under different culture conditions including PBS group (PBS replaces HUVEC), hD1R group, sup group (HUVEC supernatant replaces HUVEC), fix group (fixed HUVEC replaces HUVEC), Day 0 group (Control). Cell cycle and apoptosis of cultured cells were also analyzed. Their progeny expanded in PBS or hD1R group were transplanted into sublethally irradiated NOD/SCID mice. The percentages of human CD45⁺ (hCD45⁺) cells in the marrow of recipient mice were determined by FACS 12 weeks later.
  
  
  RESULTS
  hD1R induced more expansion in the total number of CD34⁺ cells cocultured with HUVECs plus 5GF, which was 87.50-fold increase compared to the Day 0 group, and 7.98-fold increase than that of PBS group. FACS analysis also showed that the percentage of CD34⁺ cells was 77.0% in G0/G1 phase in the hD1R group, which indicated that hD1R enhanced HSPCs expansion and inhibited apoptosis. Moreover, hD1R significantly promoted human HSPC engraftment after BM transplantation in irradiated mice.
  
  
  CONCLUSIONS
  The Notch-mediated ex vivo expansion system has been established and hD1R promoted expansion and engraftment of human CB HSPCs, which provided the evidence for further clinical application.
authors.affiliation: Department of Hematology, the 309th Hospital of Chinese People's Liberation Army, Beijing 100091, China.
authors.forename: Dengmei
authors.initials: D
authors.lastname: Tian
authors.affiliation: Department of Hematology, the 309th Hospital of Chinese People's Liberation Army, Beijing 100091, China.
authors.forename: Yingmin
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Hematology, the 309th Hospital of Chinese People's Liberation Army, Beijing 100091, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Han
authors.affiliation: Department of Hematology, the 309th Hospital of Chinese People's Liberation Army, Beijing 100091, China.
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D018952:Antigens, CD34; D002478:Cells, Cultured; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000276:immunology*; D005312:Fetal Blood; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice
chemical_list: D018952:Antigens, CD34; D008565:Membrane Proteins