Efficient transduction of skeletal muscle using vectors based on adeno-associated virus serotype 6

Vectors based on recombinant adeno-associated viruses (rAAV) have emerged as tools of choice for gene transfer to skeletal muscle. rAAV vectors demonstrate efficient, safe, and stable transduction. Multiple serotypes of AAV exist, but vectors based on serotype 2 (rAAV2) are the most thoroughly characterized and frequently employed. Here, we characterize transduction of the skeletal musculature using rAAV vectors pseudotyped with serotype 6 capsid proteins (rAAV6). We demonstrate that rAAV6 vectors can efficiently transduce the skeletal musculature of mice at levels >500-fold higher than is achievable with rAAV2 vectors and can readily saturate individual muscles following direct injection. Further, rAAV6 vectors are capable of transducing the diaphragm and intercostal muscles of mice after a simple injection into the intrathoracic cavity and are capable of widespread transduction throughout the musculature of mice injected in the intraperitoneal space as newborn pups. These results demonstrate that rAAV6 vectors hold great potential for use in gene delivery protocols targeting the skeletal musculature.