title: In vivo gene marking of rhesus macaque long-term repopulating hematopoietic cells using a VSV-G pseudotyped versus amphotropic oncoretroviral vector.
abstract: BACKGROUND
  Gene transfer efficiency into primitive hematopoietic cells may be limited by their expression of surface receptors allowing vector entry. Vectors pseudotyped with the vesicular stomatitis virus (VSV-G) envelope do not need receptors to enter cells, and therefore may provide superior transduction efficiency.
  
  
  METHODS
  Using a competitive repopulation model in the rhesus macaque, we examined in vivo gene marking levels of blood cells transduced with two vectors: (i) a VSV-G pseudotyped retrovirus and (ii) a conventional amphotropic retrovirus. The VSV-G vector, containing the human glucose-6-phosphate dehydrogenase (G6PD) gene, was constructed for treatment of severe hemolytic anemia caused by G6PD deficiency. Three myeloablated animals were transplanted with peripheral blood CD34+ cells, half of which were transduced with the VSV-G vector and the other half with the amphotropic vector.
  
  
  RESULTS
  In all animals post-transplantation, levels of in vivo marking in circulating granulocytes and mononuclear cells were similar: 1% or less with both vectors. In one animal, the human G6PD enzyme transferred by the VSV-G vector was expressed in erythrocytes, early after transplantation, at a level of 45% of the endogenous rhesus G6PD protein.
  
  
  CONCLUSIONS
  In a clinically relevant animal model, we found similar in vivo marking with a VSV-G pseudotyped and a standard amphotropic oncoretroviral vector. Amphotropic receptor expression may not be a limiting factor in transduction efficiency, but VSV-G pseudotypes possess other practical advantages that may make them advantageous for clinical use.
authors.affiliation: Hematology Branch, National Heart, Lung, and Blood Institute, National Institues of Health, Bethesda, MD 20892, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Shi
authors.forename: Maria
authors.initials: M
authors.lastname: De Angioletti
authors.forename: Robert E
authors.initials: RE
authors.lastname: Donahue
authors.forename: Rosario
authors.initials: R
authors.lastname: Notaro
authors.forename: Lucio
authors.initials: L
authors.lastname: Luzzatto
authors.forename: Cynthia E
authors.initials: CE
authors.lastname: Dunbar
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D002478:Cells, Cultured; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D005819:Genetic Markers; D005822:Genetic Vectors; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000502:physiology; D006801:Humans; D008253:Macaca mulatta / Q000097:blood* / Q000235:genetics; D012190:Retroviridae / Q000235:genetics; D014161:Transduction, Genetic; D014721:Vesicular stomatitis Indiana virus
chemical_list: D018952:Antigens, CD34; D005819:Genetic Markers; D005954:Glucosephosphate Dehydrogenase