Development of Adenovirus Hybrid Vectors for Sleeping Beauty Transposition in Large Mammals

Abstract

The Sleeping Beauty (SB) transposase system for somatic integration offers great potential for in vivo gene therapeutic applications and genome engineering. Until recently, however, efficacy of SB transposase as a gene transfer vector especially in large animals was lacking. Herein, we report about the newest viral vector development for delivery of the SB transposase system into large mammals. Over the past decade various hyperactive versions of SB transposase and advanced adenovirus vectors enabling efficient and safe delivery of transgenes in vivo were developed. Already several years ago it was demonstrated that adenovirus vectors can be used for delivery of the SB transposase system into murine liver. Our newest study showed for the first time that a hyperactive transposase system delivered by high-capacity adenoviral vectors can result in somatic integration of exogenous DNA in canine liver, facilitating stabilized transgene expression and phenotypic correction for up to three years in a canine model of human disease. In this review we discuss safety issues and further improvements of this adenovirus based hybrid vector system for somatic integration. In the future this approach paves new paths towards the possible cure of human genetic diseases and novel strategies for in vivo genome engineering in large mammals.

Integration Profile and Safety of an Adenovirus Hybrid-Vector Utilizing Hyperactive Sleeping Beauty Transposase for Somatic Integration

“…The original AdV/SB hybrid-vector system consisted of two independent HC-AdVs, of which one HC-AdV provided the integration machinery based on the unmodified version of the SB transposase and the other one contained the SB transposon carrying the transgene. This particular molecular design was called “two-vector-system” [12], [18]. For further improvements hyperactive versions of the SB transposase were generated including the hyperactive mutants HSB5 and SB100× with 10- to 100-fold increased integration efficiencies [19], [20].…”

Gene therapy for hemophilia

“…Ironically, in order to achieve targeted delivery of transposon/integrase systems, some investigators have returned to viral vectors. For instance, engineered adenoviral vectors incorporating SB transposons have been used to achieve sustained F.IX expression in mice and in hemophilic dogs (182-184). …”

DNA transposon-based gene vehicles - scenes from an evolutionary drive

“…Most recently, we developed lentiviral protein transduction for direct delivery of transposase protein, allowing efficient DNA transposition in lentivirally transduced cells (Figure 7, panel d) [215]. Efforts to combine viral gene delivery with non-viral integration systems in ‘hybrid’ vectors have recently been reviewed [209,216,217]. …”