Introducing a Novel Method of Intravascular Adeno-associated Virusmediated Gene Delivery

Introduction: Adeno-associated virus (AAV) has shown therapeutic potential as a viral vector in various studies of gene therapy. However, research on its use in targeting intravascular cells in a localized manner is lacking. We introduce a novel method to deliver various AAV serotypes intravascularly and examine their efficiency in transducing cells of the murine carotid artery. Objective: The study aimed to examine the transduction efficiency of AAV-mediated gene delivery in cells of the murine carotid artery both with and without a fully-formed aneurysm. Results of infection were visualized with green fluorescence protein (GFP) reporter gene. Methods: Naive murine carotid artery or experimentally-induced murine carotid aneurysm was ligated distally and proximally. A small incision was made and 5 uL AAV2, AAV5, AAV8, or AAV9 was microsurgically injected and allowed to incubate for 30 min. Incision was closed and tissue was excised three weeks following AAV injection. Carotid artery or aneurysm tissue was excised and fixed in 4% paraformaldehyde solution. On both naive carotid artery tissue and aneurysm tissue, GFP was visualized by immunofluorescence using antibody against GFP. Results: Three out of four serotypes of AAV successfully transduced cells within both the murine aneurysm tissue and the naive carotid artery tissue. AAV5- and AAV9-transduced aneurysm tissue showed the greatest presence of GFP, with AAV8 showing less overall fluorescence. AAV2 showed no fluorescence. Conclusion: AAV-mediated gene delivery is an effective way to transduce cells intravascularly with a transgene of interest. Our method can be generalized across a wide variety of studies to further research or treat other vascular disease.