title: Cord blood CD34+ cells expanded on Wharton's jelly multipotent mesenchymal stromal cells improve the hematopoietic engraftment in NOD/SCID mice.
abstract: OBJECTIVE
  This study aims to investigate the capability of Wharton's jelly multipotent mesenchymal stromal cells (WJ-MSC) to support the in vitro expansion of hematopoietic stem/progenitor cells (HSPC) derived from cord blood (CB) in the absence of exogenous cytokines, and the effect on engraftment of the expanded cells in a mouse model.
  
  
  METHODS
  CB-CD34+ cells were seeded on WJ-MSC layer and cultured in HP01 serum-free medium. Day-7 and day-13 expanded cells were transplanted in NOD/SCID mice. After 8 wk, engraftment was evaluated in mouse bone marrow as percentage of human CD45+ cells.
  
  
  RESULTS
  CD34+ population was expanded without increasing the differentiation rate. Co-culture increased the expansion of the CD34+ cells by 2.0 and 7.3 times after 7 and 13 d, respectively, and maintained the CD34+ cells up to day 20. In particular, earlier CD34+/CD90+ and CD34+/CD33- subtypes were increased. An advantage of the day-7 co-cultured HSPC in respect of HSPC at day 0 in the engraftment of NOD/SCID mice was obtained both as percentage of mice engrafted (100% vs. 75%) and as percentage of chimerism.
  
  
  CONCLUSIONS
  Although the increase in hematopoietic progenitors is not dramatic as in the presence of added cytokines, this study demonstrates the effectiveness of the WJ-MSC not only to preserve the CD34+ population but also to improve the repopulating efficacy of the amplified HSPC, also in the absence of added cytokines and growth factors.
authors.affiliation: Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Milazzo
authors.forename: Francesca
authors.initials: F
authors.lastname: Vulcano
authors.forename: Alessandra
authors.initials: A
authors.lastname: Barca
authors.forename: Giampiero
authors.initials: G
authors.lastname: Macioce
authors.forename: Emanuela
authors.initials: E
authors.lastname: Paldino
authors.forename: Stefania
authors.initials: S
authors.lastname: Rossi
authors.forename: Carmela
authors.initials: C
authors.lastname: Ciccarelli
authors.forename: Hamisa J
authors.initials: HJ
authors.lastname: Hassan
authors.forename: Adele
authors.initials: A
authors.lastname: Giampaolo
mesh_terms: D000818:Animals; D018952:Antigens, CD34; D015415:Biomarkers; D049109:Cell Proliferation; D018920:Coculture Techniques; D005260:Female; D005312:Fetal Blood / Q000166:cytology* / Q000378:metabolism; D015870:Gene Expression; D006085:Graft Survival; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D018183:Transplantation Chimera; D014183:Transplantation, Heterologous; D059631:Wharton Jelly / Q000166:cytology* / Q000378:metabolism; D014916:Whole-Body Irradiation
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers
keywords: Wharton's jelly; cord blood transplantation; hematopoietic engraftment; multipotent mesenchymal stromal cells; non-obese diabetic/severe combined immunodeficient mice