Femoral intra-arterial injection: a tool to deliver and assess recombinant AAV constructs in rodents whole hind limb

With the aim of simplifying recombinant-adeno-associated virus (rAAV) delivery in muscle, a new femoral intra-arterial technique was designed and tested in rodents (rats and mice). Two serotypes, several promoters and transgenes (reporter or therapeutic) were tested using this administration route. The new route is both easy to perform and efficient. Its usefulness as a tool to assess gene delivery constructs in the muscle was established in the context of recombinant AAV serotypes 1 and 2, and with the ubiquitous CMV and two muscle-specific (C5-12 and CK6) promoters. Both serum monitoring of a secreted protein (murine alkaline phosphatase: muSEAP) and slide staining were used to compare the different constructs. Significantly different patterns of expression in kinetics of expression (muSEAP) and homogeneity of fiber transduction (staining) were evidenced with the different promoters tested, and compared with intra-muscular expression patterns. Detailed studies of differential transduction in leg and thigh muscles showed equivalent efficacy, except in rectus femoris, and to a lesser extent in soleus. In light of these results and prior data, intra-arterially mediated gene transfer mechanism is discussed.