Scaffold attachment region-containing retrovirus vectors improve long-term proviral expression after transplantation of GFP-modified CD34+ baboon repopulating cells.
Sustained high-level proviral expression is important for clinical applications of gene therapy. Genetic elements including the beta-interferon scaffold attachment region (SAR) have been shown to improve transgene expression in hematopoietic cells. We hypothesized that SAR elements might improve expression and allow the preselection of successfully transduced cells. Thus, we transplanted green fluorescent protein (GFP)-selected cells, half of which had been transduced with either SAR or non-SAR-containing retrovirus vectors, into 3 animals. All animals showed delayed engraftment compared with historic controls (28 vs 15.5 days). GFP marking was seen at levels up to 8% but declined over the first 6 weeks. Importantly, fluorescence intensity was 2- to 9-fold increased in progeny of SAR versus non-SAR vector-modified cells in all hematopoietic lineages for the duration of follow-up (6-12 months). In conclusion, the use of SAR-containing vectors improved transgene expression in hematopoietic repopulating cells, which may obviate the need for multicopy integration to achieve high-level expression and reduce the risk for insertional mutagenesis.
Kurre
Peter
P
Clinical Research Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA 98109, USA.
Morris
Julia
J
Thomasson
Bobbie
B
Kohn
Donald B
DB
Kiem
Hans-Peter
HP
D000818:Animals; D015870:Gene Expression; D005822:Genetic Vectors; D006085:Graft Survival; D049452:Green Fluorescent Proteins; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism; D007700:Kinetics; D008164:Luminescent Proteins / Q000235:genetics; D045170:Matrix Attachment Regions / Q000235:genetics*; D010215:Papio; D011533:Proviruses / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012190:Retroviridae / Q000235:genetics; D013997:Time Factors; D014161:Transduction, Genetic / Q000379:methods* / Q000592:standards
D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins