In vivo gene marking of rhesus macaque long-term repopulating hematopoietic cells using a VSV-G pseudotyped versus amphotropic oncoretroviral vector.
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.
Shi
Patricia A
PA
Hematology Branch, National Heart, Lung, and Blood Institute, National Institues of Health, Bethesda, MD 20892, USA.
De Angioletti
Maria
M
Donahue
Robert E
RE
Notaro
Rosario
R
Luzzatto
Lucio
L
Dunbar
Cynthia E
CE
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
D018952:Antigens, CD34; D005819:Genetic Markers; D005954:Glucosephosphate Dehydrogenase