title: A Stro-1(+) human universal stromal feeder layer to expand/maintain human bone marrow hematopoietic stem/progenitor cells in a serum-free culture system.
abstract: OBJECTIVE
  To compare the ability of allogeneic versus autologous purified human Stro-1(+) mesenchymal stem cell (MSC) populations from different human donors to support the ex vivo expansion and maintenance of human hematopoietic stem/progenitor cells (HSCs). Furthermore, we compared the results obtained with MSC as a feeder layer to traditional allogeneic stromal layers grown in long-term bone marrow culture media (LT-ST).
  
  
  METHODS
  Adult human bone marrow CD34(+)-enriched cells were cultured in serum-free medium for 2 to 3 weeks over the respective MSC-irradiated feeder layers or over traditional allogeneic LT- ST stromal layers in the presence of stem cell factor, basic fibroblast growth factor, leukemia inhibitory factor, and Flt-3 and analyzed every 2 to 4 days for expansion, phenotype, and clonogenic ability.
  
  
  RESULTS
  There was a progressive expansion of total numbers of cells in all the experimental groups; however, allogeneic MSCs were more efficient at expanding CD34(+)CD38(-) cells and showed a higher clonogenic potential than both allogeneic LT-ST and autologous MSCs. The differentiative potential of cells cultured on both MSC and LT-ST was primarily shifted toward myeloid lineage; however, only MSCs were able to maintain/expand a CD7(+) population with lymphocytic potential. Importantly, transplantation into preimmune fetal sheep demonstrated that the HSCs cultured over MSCs retained their engraftment capability.
  
  
  CONCLUSIONS
  These results indicate that purified Stro-1(+) MSCs may be used as a universal and reproducible stromal feeder layer to efficiently expand and maintain human bone marrow HSCs ex vivo.
authors.affiliation: Department of Animal Biotechnology, University of Nevada, Reno, NV 89557, USA.
authors.forename: Raquel
authors.initials: R
authors.lastname: Gonçalves
authors.forename: Cláudia
authors.initials: C
authors.lastname: Lobato da Silva
authors.forename: Joaquim M S
authors.initials: JM
authors.lastname: Cabral
authors.forename: Esmail D
authors.initials: ED
authors.lastname: Zanjani
authors.forename: Graça
authors.initials: G
authors.lastname: Almeida-Porada
mesh_terms: D051997:ADP-ribosyl Cyclase 1; D018952:Antigens, CD34; D002478:Cells, Cultured; D018920:Coculture Techniques; D016895:Culture Media, Serum-Free; D006133:Growth Substances / Q000494:pharmacology; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D017154:Stromal Cells / Q000166:cytology; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous
chemical_list: D018952:Antigens, CD34; D016895:Culture Media, Serum-Free; D006133:Growth Substances; D051997:ADP-ribosyl Cyclase 1