Institute of Biomedical and Biomolecular Science (IBBS)

Cellular targeting and trafficking of non-viral vectors

To achieve long-term gene expression, targeting vectors must navigate a series of extracellular and intracellular obstacles (Fig.1) before reaching nuclei of the target cells, where the therapeutic gene can be expressed. Poor nuclear entry, especially into non-dividing cells, is a limiting factor in non-viral gene delivery

We have engineered a novel chimeric vector relying on the controlled assembly of a TAT-tagged multi-subunit DNA binding protein with expression plasmids containing specific recognition site. Maintenance of nano-complexes in an appropriate stoichiometric ratio was both necessary and sufficient to produce >8-fold increase in the activity of the therapeutic alpha-galactosidase A following intramuscular administration in the model of Fabry disease.

Cell penetration peptides (CPP), such as TAT, have been shown to improve delivery of macromolecules, when linked directly. In our system TAT-enhanced targeting took place even though it was linked to the DNA molecule indirectly, via two non-covalent bonds. This result indicates that CPP can be used for targeting modular vectors and therapeutic nano-devices (Lavigne et al, FASEB J 2008).