%0 Journal Article %T Gene Transfer of Heme Oxygenase-1 Using an Adeno-Associated Virus Serotype 6 Vector Prolongs Cardiac Allograft Survival %A Jacqueline M. Evans %A Sonia Navarro %A Tomoko Doki %A John M. Stewart %A Noboru Mitsuhashi %A Mary Kearns-Jonker %J Journal of Transplantation %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/740653 %X Introduction. Allograft survival can be prolonged by overexpression of cytoprotective genes such as heme oxygenase-1 (HO-1). Modifications in vector design and delivery have provided new opportunities to safely and effectively administer HO-1 into the heart prior to transplantation to improve long-term graft outcome. Methods. HO-1 was delivered to the donor heart using an adeno-associated virus vector (AAV) with a pseudotype 6 capsid and vascular endothelial growth factor (VEGF) to enhance myocardial tropism and microvascular permeability. Survival of mouse cardiac allografts, fully or partially mismatched at the MHC, was determined with and without cyclosporine A. Intragraft cytokine gene expression was examined by PCR. Results. The use of AAV6 to deliver HO-1 to the donor heart, combined with immunosuppression, prolonged allograft survival by 55.3% when donor and recipient were completely mismatched at the MHC and by 94.6% if partially mismatched. The combination of gene therapy and immunosuppression was more beneficial than treatment with either AAV6-HO-1 or CsA alone. IL-17a, b, e and f were induced in the heart at rejection. Conclusions. Pretreatment of cardiac allografts with AAV6-HO-1 plus cyclosporine A prolonged graft survival. HO-1 gene therapy represents a beneficial adjunct to immunosuppressive therapy in cardiac transplantation. 1. Introduction Chronic graft vasculopathy (CGV), also referred to as ˇ°transplant-associated arteriosclerosis,ˇ± is a widespread and progressive process characterized by intimal hyperplasia, inflammation, and fibrosis of the graft arterial microvasculature [1]. CGV is a major challenge for heart and other organ transplant recipients [1¨C4]. Although modern immunosuppressive agents have significantly improved short-term outcomes, long-term outcomes have been less favorable [4]. Ten year survival of adults undergoing heart transplantation is currently at 55% [5]. Moreover, immunosuppressive therapy is hampered by a multitude of potentially life-threatening side effects as well as the need for lifelong compliance and rigorous monitoring [4, 6]. Tissue-directed gene therapy in which a therapeutic molecule is produced within the graft itself could reduce the necessity for systemic immunosuppressive agents [7]. Candidate cytoprotective genes include various heat shock proteins (HSPs) [8], B-cell leukemia/lymphoma-2(bcl-2), nitric oxide synthase, interleukins 4 and 10 [9, 10], and transforming growth factor- (TGF- ) [11]. The well-characterized gene heme oxygenase-1 (HO-1, HSP-32) prevents ischemia reperfusion (I/R) injury %U http://www.hindawi.com/journals/jtrans/2012/740653/