Efficient transduction and engraftment of G-CSF-mobilized peripheral blood CD34+ cells in nonhuman primates using GALV-pseudotyped gammaretroviral vectors

Mol Ther. 2006 Aug;14(2):212-7. doi: 10.1016/j.ymthe.2006.01.016. Epub 2006 Apr 21.


The optimal stem cell source for stem cell gene therapy has yet to be determined. Most large-animal studies have utilized peripheral blood or marrow-derived cells collected after administration of granulocyte colony-stimulating factor (G-SCF) and stem cell factor (SCF); however, SCF is unavailable for clinical use in the United States and the European Union. A recent study in a competitive repopulation assay in the rhesus macaque showed very inefficient marking of G-CSF-mobilized (G/only) peripheral blood (G-PBSC) CD34(+) cells relative to G-CSF and SCF-mobilized cells using vectors with an amphotropic pseudotype. Because G-PBSC would be the preferred target cell population for most clinical stem cell gene therapy applications, we asked whether we could achieve efficient transduction and engraftment of G-PBSC using Phoenix-GALV-pseudotyped vectors. We transplanted three baboons with G/only mobilized CD34(+) cells transduced with GALV-pseudotyped retroviral vectors. We observed high-level, persistent engraftment of gene-modified G-PBSC in all animals with gene marking levels in granulocytes up to 60%. We analyzed amphotropic (PIT2) and GALV (PIT1) receptor expression in G/only cells and found preferential expression of PIT1 after G/only, which may explain the inferior results with amphotropic pseudotypes. These findings demonstrate that high stem cell gene transfer levels can be achieved using G-CSF-mobilized PBSC with Phoenix-GALV-pseudotyped vectors.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antigens, CD34 / analysis
  • Flow Cytometry
  • Gene Transfer Techniques
  • Granulocyte Colony-Stimulating Factor / pharmacology*
  • Hematopoiesis
  • Hematopoietic Stem Cell Mobilization*
  • Hematopoietic Stem Cell Transplantation*
  • Humans
  • Leukemia Virus, Gibbon Ape / genetics*
  • Papio
  • Recombinant Proteins
  • Sodium-Phosphate Cotransporter Proteins, Type III / analysis
  • Transduction, Genetic*


  • Antigens, CD34
  • Recombinant Proteins
  • Sodium-Phosphate Cotransporter Proteins, Type III
  • Granulocyte Colony-Stimulating Factor