Myocardial gene transfer and long‐term expression following intracoronary delivery of adeno‐associated virus

Abstract

Adeno-associated viral vectors (AAV) can direct long-term gene expression in post-mitotic cells. Previous studies have established that long-term cardiac gene transfer results from intramuscular injection into the heart. Cardiac gene transfer after direct intracoronary delivery of AAV in vivo, however, has been minimal in degree, and indirect intracoronary delivery, an approach used in an increasing number of studies, appears to be receiving more attention. To determine the utility of indirect intracoronary gene transfer of AAV, we used aortic and pulmonary artery cross clamping followed by proximal aortic injection of AAV encoding enhanced green fluorescent protein (AAV.EGFP) at 10(11) DNase resistant particles (drp; high-performance liquid chromatography (HPLC)-purified) per rat. Gene expression was quantified by fluorescent microscopy at four time points up to 1 year after vector delivery, revealing 20-32% transmural gene expression in the left ventricle at each time point. Histological analysis revealed little or no inflammatory response and levels of transgene expression were low in liver and undetectable in lung. In subsequent studies in pigs, direct intracoronary delivery into the left circumflex coronary artery of AAV.EGFP (2.64-5.28 x 10(13) drp; HPLC-purified) resulted in gene expression in 3 of 4 pigs 8 weeks following injection with no inflammatory response in the heart. PCR analysis confirmed AAV vector presence in the left circumflex perfusion bed. These data indicate that intracoronary delivery of AAV vector is associated with transgene expression in the heart, providing a means to obtain long-term expression of therapeutic genes.

Cardio-specific long-term gene expression in a porcine model after selective pressure-regulated retroinfusion of adeno-associated viral (AAV) vectors

“…8,20,21 Recent advances in AAV vector development resulted in vectors that can be applied efficiently via a transvascular route-at least in rodents. [2][3][4][5]8 These so called pseudotyped vectors take advantage of the ability of certain AAV serotypes to efficiently cross the blood vessel barrier. Systemic application of pseudotyped AAV-6, -8 or -9 vectors resulted in uniform and extensive transfer of a lacZ reporter gene in adult mice.…”

“…It has been previously demonstrated that transvascular (intracoronary or retrograde coronary venous) application of vectors for gene therapy is feasible. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] We have chosen pressure-regulated retroinfusion of the coronary veins, as a catheterbased delivery system, which has been previously proven to be safe for human application. 15,16 Recently, it has been shown to provide efficient gene transfer to ischemic and nonischemic myocardium.…”

Long-term expression and repeated administration of AAV type 1, 2 and 5 vectors in skeletal muscle of immunocompetent adult mice

“…[1][2][3][4][5] Skeletal muscles represent an essential target for numerous clinical applications such as neuromuscular disorders 6 or clinical conditions in which a reservoir strategy for a therapeutic protein is envisaged. 7,8 Efficient fiber transduction following rAAV2-mediated gene transfer, although initially judged to be very encouraging, 9 has been disappointing in further studies in large animal models and in humans, due to the immune reaction and insufficient level of gene expression.…”

Differential internalization and nuclear uncoating of self-complementary adeno-associated virus pseudotype vectors as determinants of cardiac cell transduction

“…AAV vectors have already been employed for therapeutic gene transfer into the myocardium in several animal models of human cardiovascular diseases. [1][2][3][4][5][6][7][8][9][10][11][12] Multiple AAV serotypes have been isolated in recent years which show grossly different tissue and organ tropisms. [14][15][16][17][18][19][20] This may be due to different cellular receptor affinities of the respective AAV virions, but for only few of the currently known AAV types the cellular receptors are currently known.…”