The Use of Adeno-Associated Virus to Circumvent the Maturation-Dependent Viral Transduction of Muscle Fibers

Abstract

Muscle-based gene therapy using adenovirus, retrovirus, and herpes simplex virus has been hindered by viral cytotoxicity, host immune response, and the maturation-dependent viral transduction of muscle fibers. The development of new mutant vectors has greatly reduced the toxicity and the immune rejection problems, but the inability of viral vectors to penetrate and transduce mature myofibers remains an important issue. Research has been focused on the characterization of barriers to viral transduction in mature myofibers to develop strategies to circumvent the maturation-dependent viral transduction of myofibers. Here, we report that adeno-associated virus (AAV) can be used to overcome the maturation-dependent viral transduction of myofibers. We have investigated by which mechanism AAV can penetrate and efficiently transduce mature muscle fibers, and have shown that this viral vector is not blocked by the basal lamina and that AAV transduction of myofibers is independent of myoblast mediation. Although AAV can efficiently transduce mature myofibers, a differential transduction is still observed among the different types of myofibers that correlates with the expression of the heparan sulfate proteoglycan receptors, the muscle maturity, the number of viral particles used, and the time postinjection. The identification of the mechanisms by which AAV transduces mature myofibers will help in the development of strategies to achieve an efficient muscle-based gene therapy for inherited and acquired diseases.

Efficient and long-term intracardiac gene transfer in δ-sarcoglycan-deficiency hamster by adeno-associated virus-2 vectors

“…However, for hereditary cardiomyopathies and other heart conditions where extensive gene transfer is required, adenoviral and nonviral vectors would face formidable hurdles to achieve widespread transgene expression. When delivered through blood circulation, both Ad vectors and naked plasmid DNA were not only hindered by their size constraint in exiting the capillary blood vessels, but also limited by the extracellular matrix barrier 32,33 and the lack of receptors for naked DNA on the cardiomyocytes. Recently, Ad vectors carrying Lac-Z reporter gene and d-sarcoglycan gene were delivered into the heart of normal and Bio14.6 hamster hearts after transient aortic occlusion.…”

Non-viral gene delivery in skeletal muscle: a protein factory

“…The pore size of basal lamina has also been shown to selectively limit the penetration of larger viruses, such as adenovirus, by comparison with the smaller ones, such as AAV. 102 Such size constraints may also be limiting factors for efficient delivery of large plasmids. To improve dissemination of both viral and non-viral vectors, some proteases have been tested for their ability to break down the barriers.…”

Adeno-associated virus-mediated gene transfer of the heart/muscle adenine nucleotide translocator (ANT) in mouse

“…By contrast, virus-mediated gene transduction, particularly using adeno-associated viral (AAV) vectors 12 has proven more successful. The nonpathogenic AAV has a relatively high affinity for muscle 13 and can efficiently infect both dividing and nondividing muscle cells. Infection with recombinant AAV (rAAV) virus results in both a persistent episomal form as well as integration into the host genome.…”