1. Long-term transgene expression from plasmid DNA gene therapy vectors is negatively affected by CpG dinucleotides.
- Author
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Hodges BL, Taylor KM, Joseph MF, Bourgeois SA, and Scheule RK
- Subjects
- Animals, Cytomegalovirus genetics, DNA Methylation, DNA, Superhelical genetics, DNA, Superhelical metabolism, Factor IX analysis, Factor IX metabolism, Gene Expression, Hemophilia A therapy, Humans, Liver chemistry, Liver metabolism, Lysosomal Storage Diseases therapy, Mice, Promoter Regions, Genetic genetics, RNA, Messenger analysis, RNA, Messenger metabolism, Transduction, Genetic methods, Transgenes genetics, alpha-Galactosidase blood, alpha-Galactosidase metabolism, CpG Islands genetics, Factor IX genetics, Genetic Therapy methods, Genetic Vectors genetics, Plasmids genetics, alpha-Galactosidase genetics
- Abstract
CpG-reduced, CMV-based plasmid DNA constructs encoding human alpha-galactosidase A and factor IX were injected into C57Bl/6, BALB/c, and CD1 mice using hydrodynamics-based delivery of plasmid DNA (pDNA), and gene expression was monitored for 6 months. Linearized and supercoiled pDNAs were compared for their abilities to support long-term expression and to generate immune responses to the transgene product. In all mouse strains supercoiled CpG-reduced pDNA encoding alpha-galactosidase A and factor IX generated higher and more sustained levels of circulating gene product than their supercoiled CpG-replete analogs. Linearizing supercoiled CpG-reduced pDNA did not significantly increase levels of circulating gene product beyond levels supercoiled CpG-reduced pDNA could achieve. Linearizing supercoiled CpG-replete pDNA vectors significantly increased expression compared to their supercoiled CpG-replete analogs, but the increase was short-lived or subtherapeutic. Regardless of vector, liver depot expression did not elicit significant antibody responses to human alpha-galactosidase A or factor IX. Taken together, these data suggest that a clinically acceptable hydrodynamics-based approach targeting the liver combined with CpG-reduced pDNA vectors may represent a viable option for individuals with hemophilia, a lysosomal storage disease, or other disease in which prolonged depot expression of a therapeutic protein from the liver is desirable., (Copyright The American Society of Gene Therapy)
- Published
- 2004
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