Endothelial Cells Promote Expansion of Long-Term Engrafting Marrow Hematopoietic Stem and Progenitor Cells in Primates

Stem Cells Transl Med. 2017 Mar;6(3):864-876. doi: 10.5966/sctm.2016-0240. Epub 2016 Oct 14.


Successful expansion of bone marrow (BM) hematopoietic stem and progenitor cells (HSPCs) would benefit many HSPC transplantation and gene therapy/editing applications. However, current expansion technologies have been limited by a loss of multipotency and self-renewal properties ex vivo. We hypothesized that an ex vivo vascular niche would provide prohematopoietic signals to expand HSPCs while maintaining multipotency and self-renewal. To test this hypothesis, BM autologous CD34+ cells were expanded in endothelial cell (EC) coculture and transplanted in nonhuman primates. CD34+ C38- HSPCs cocultured with ECs expanded up to 17-fold, with a significant increase in hematopoietic colony-forming activity compared with cells cultured with cytokines alone (colony-forming unit-granulocyte-erythroid-macrophage-monocyte; p < .005). BM CD34+ cells that were transduced with green fluorescent protein lentivirus vector and expanded on ECs engrafted long term with multilineage polyclonal reconstitution. Gene marking was observed in granulocytes, lymphocytes, platelets, and erythrocytes. Whole transcriptome analysis indicated that EC coculture altered the expression profile of 75 genes in the BM CD34+ cells without impeding the long-term engraftment potential. These findings show that an ex vivo vascular niche is an effective platform for expansion of adult BM HSPCs. Stem Cells Translational Medicine 2017;6:864-876.

Keywords: Bone marrow transplantation; CD34+ cells; Endothelial cells; Gene therapy; Hematopoietic stem progenitor cell.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD34 / metabolism
  • Bone Marrow Cells / cytology*
  • Cell Lineage
  • Cell Proliferation
  • Endothelial Cells / cytology*
  • Endothelial Cells / metabolism
  • Gene Expression Profiling
  • Hematopoiesis
  • Hematopoietic Stem Cell Transplantation*
  • Hematopoietic Stem Cells / cytology*
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Primates
  • Time Factors


  • Antigens, CD34