title: Foamy-virus-mediated gene transfer to canine repopulating cells.
abstract: Foamy virus (FV) vectors are particularly attractive gene-transfer vectors for stem-cell gene therapy because they form a stable transduction intermediate in quiescent cells and can efficiently transduce hematopoietic stem cells. Here, we studied the use of FV vectors to transduce long-term hematopoietic repopulating cells in the dog, a clinically relevant large animal model. Mobilized canine peripheral blood (PB) CD34+ cells were transduced with an enhanced green fluorescent protein (EGFP)-expressing FV vector in an 18-hour transduction protocol. All 3 dogs studied had rapid neutrophil engraftment to greater than 500/microL with a median of 10 days. Transgene expression was detected in all cell lineages (B cells, T cells, granulocytes, red blood cells, and platelets), indicating multilineage engraftment of transduced cells. Up to 19% of blood cells were EGFP+, and this was confirmed at the DNA level by real-time polymerase chain reaction (PCR) and Southern blot analysis. These transduction rates were higher than the best results we obtained previously with lentiviral vectors in a similar transduction protocol. Integration site analysis also demonstrated polyclonal repopulation and the transduction of multipotential hematopoietic repopulating cells. These data suggest that FV vectors should be useful for stem-cell gene therapy, particularly for applications in which short transduction protocols are critical.
authors.affiliation: Clinical Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N D1-100, PO Box 19024, Seattle, WA 98109-1024, USA. hkiem@fhcrc.org
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Kiem
authors.forename: James
authors.initials: J
authors.lastname: Allen
authors.forename: Grant
authors.initials: G
authors.lastname: Trobridge
authors.forename: Erik
authors.initials: E
authors.lastname: Olson
authors.forename: Kirsten
authors.initials: K
authors.lastname: Keyser
authors.forename: Laura
authors.initials: L
authors.lastname: Peterson
authors.forename: David W
authors.initials: DW
authors.lastname: Russell
mesh_terms: D000818:Animals; D001773:Blood Cells / Q000166:cytology / Q000378:metabolism; D015139:Blotting, Southern; D019070:Cell Lineage; D003114:Colony-Forming Units Assay; D004285:Dogs; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000235:genetics*; D006085:Graft Survival; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000821:virology*; D051379:Mice; D036102:Peripheral Blood Stem Cell Transplantation; D010735:Phosphoglycerate Kinase / Q000235:genetics; D016133:Polymerase Chain Reaction; D011828:Radiation Chimera; D016092:Spumavirus / Q000235:genetics*; D014161:Transduction, Genetic; D019076:Transgenes; D014182:Transplantation, Autologous
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D010735:Phosphoglycerate Kinase