These include difficulties in large scale production, the high cost of the recombinant enzyme, the need for repeated and life-long infusions, as well the possibility that current dosing regimens may not be adequate to treat all muscle cells in an affected individual. These realities have prompted our research interest

into alternative therapeutic options for GSD-II patients. Past and ongoing developments within our Inhibitors,research,lifescience,medical laboratories show the promise of virus mediated gene transfer of the hGAA gene for potential therapeutic use in all GSD-II patients. Gene Therapy for GSD-II Clearly, any gene transfer “vector” will have advantages and limitations depending on the specific requirements of the gene therapy application. Virus based JNK inhibitor in vivo vectors are generated by recombinant Inhibitors,research,lifescience,medical DNA technologies, in which deleterious virus genes are removed, and replaced with desirable gene products, such as the hGAA gene (5). Use of appropriate packaging cell lines allows high level growth of the recombinant vectors in tissue culture, and the vectors are purified to high concentration for use in animal models. The two predominantly used gene transfer vectors for GSD-II treatment are Adeno-associated viruses (AAV) and Adenoviruses (Ads).

These viral vectors Inhibitors,research,lifescience,medical have been confirmed to be able to “transduce” the human GAA (hGAA) gene to target cells in tissue culture systems, as Inhibitors,research,lifescience,medical well several animal models of GSD-II. Adenovirus (Ad) based gene therapy for GSD-II: Ad based vectors are one of the best characterized gene transfer vectors; their numerous benefits have made them widely useful in basic biology studies, cell and gene therapy applications, as well for vaccine development (6–9). Using an in vitro model, it was demonstrated that an Ad vector could mediated transfer of a GAA gene into cultured fibroblasts and myotubes from a GSD-II patient, and this resulted in: 1) de novo synthesis of GAA enzyme, 2) clearance of lysosomal glycogen, and 3) secretion of 110 kDA GAA being taken up by recipient Inhibitors,research,lifescience,medical cells (10). Subsequently, in vivo studies showed that there was insufficient secretion

of muscle derived hGAA to allow cross-correction of non-transduced muscle cells (11–13). For example, Pauly and colleagues demonstrated that intramuscular injection into cardiac or skeletal muscles of normal neonatal rats 17-DMAG (Alvespimycin) HCl of a first generation Ad vectors expressing hGAA resulted in high levels of GAA expression only within the injected muscles, but systemic correction of non-injected muscles was not achieved (14). Obviously, any therapeutic strategy for GSD-II should allow for treatment of all muscle cells in an affected individual. This is a significant hurdle to surpass, as up to 40% of one’s mass may be muscle tissue. Due to this significant limitation, we set out to create a system that could achieve this goal.