Gene Expression in Lung and Liver After Intravenous Infusion of Polyethylenimine Complexes of Sleeping Beauty Transposons

Abstract

Two methods of systemic gene delivery have been extensively explored, using the mouse as a model system: hydrodynamic delivery, wherein a DNA solution equivalent in volume to 10% of the mouse weight is injected intravenously in less than 10 sec, and condensation of DNA with polyethylenimine (PEI) for standard intravenous infusion. Our goal in this study was to evaluate quantitatively the kinetics of gene expression, using these two methods for delivery of Sleeping Beauty transposons. Transposons carrying a luciferase expression cassette were injected into mice either hydrodynamically or after condensation with PEI at a PEI nitrogen-to-DNA phosphate ratio of 7. Gene expression in the lungs and liver after hydrodynamic delivery resulted in exponential decay with a half-life of about 35-40 hr between days 1 and 14 postinjection. The decay kinetics of gene expression after PEI-mediated gene delivery were more complex; an initial decay rate of 6 hr was followed by a more gradual loss of activity. Consequently, the liver became the primary site of gene expression about 4 days after injection of PEI-DNA, and by 14 days expression in the liver was 10-fold higher than in the lung. Overall levels of gene expression 2 weeks postinjection were 100-to 1000-fold lower after PEI-mediated delivery compared with hydrodynamic injection. These results provide insight into the relative effectiveness and organ specificity of these two methods of nonviral gene delivery when coupled with the Sleeping Beauty transposon system.

Long-Term Prevention of Congenital Thrombotic Thrombocytopenic Purpura in ADAMTS13 Knockout Mice by Sleeping Beauty Transposon-Mediated Gene Therapy

“…Condensation of the SB plasmids with polyethylenimine or encapsulation in nanocapsules for standard intravenous infusion may be an interesting alternative to deliver the transgene into the liver. 40,41 A second issue regarding the clinical use of the SB transposon system is the safety of SB-mediated integration. It has been shown that SB has no preference for integration into transcription units and transcriptional regulatory regions and that the majority of insertions that do occur in genes are located in introns.…”

Transposons: Moving Forward from Preclinical Studies to Clinical Trials

“…As an alternative, PEI transfection has been explored as an alternative to HD in order to mediate in vivo transposon delivery through intravenous infusion into mice but was at least 100-fold less efficient compared to HD delivery. 167 Recently, in vivo administration of nanoparticles carrying transposons has emerged as an efficient method to deliver transgenes into circulating T cells in mice, and in situ engineered T cells exhibited similar activity to conventional engineered T cells generated by ex vivo gene transfer. 168 Nanoparticles represents a potentially attractive technology to deliver transposons into liver sinusoidal endothelial cells.…”

Using a magnetic field to redirect an oncolytic adenovirus complexed with iron oxide augments gene therapy efficacy

“…Previous studies demonstrated significant liver tropism of PLLand PEI-based cationic polymers in biodistribution studies [36,37]. To gain insight on the mobility of HmT-PCION complex in vivo, IVIS whole-body luciferase assays were performed to track the movement of HmT-PCION in a MCF7 tumor-bearing mouse model after treatment with PBS with MGF, HmT with MGF, or HmT-PCION with or without MGF (Fig.…”