Atheroprotective Gene Therapy

描述（由申请人提供）：动脉粥样硬化是一种血管壁疾病，可导致心脏病发作、中风和肢体丧失。尽管在内科和外科治疗方面取得了重大进展，但动脉粥样硬化仍然导致显著的发病率和死亡率。由于人口老龄化和当前肥胖/糖尿病流行的后果，动脉粥样硬化对美国人民健康的影响预计将在未来几十年内增加。该项目广泛的长期目标是开发一种新的治疗方法，降低动脉粥样硬化的发病率和死亡率。这种新的疗法涉及在血管壁细胞中引入和表达疾病预防基因，并被适当地称为“动脉粥样硬化保护基因疗法”。用动脉粥样硬化保护基因疗法治疗的血管不会发展成动脉粥样硬化，因为它们已经被基因修饰以抵抗导致动脉粥样硬化的潜在生物过程，包括炎症和血管壁中脂肪沉积的积累。有三个具体的目标，所有这些都是在兔子身上进行的。其目的是开发临床上有用的动脉粥样硬化保护基因治疗，通过一个有前途的基因转移载体，“辅助依赖性腺病毒”（HDAd）。HDAd是一种有吸引力的人类基因治疗载体，因为它在动物（包括非人灵长类动物）中稳定表达治疗基因多年，并且相对非炎症。这三个具体目标利用HDAd的前景来解决临床前基因治疗研究中的关键问题：1）在人类疾病的大型动物模型中证明长期疗效和无毒性（目标1和3）; 2）实现足够高的转基因表达水平，以治疗和预防慢性疾病，同时最大限度地减少对大量载体输注的需求（目标2）。第一个具体目的是使用2个动脉粥样硬化病变生长的动物模型和一个动脉粥样硬化消退的模型来测试载脂蛋白A-I在动脉内皮细胞中的表达， 细胞可以防止新的动脉粥样硬化损伤的生长并促进现有损伤的消退。第二个具体目标是开发改进的表达盒，使HDAd以更高、更稳定的水平表达治疗基因，特别是在内皮细胞中。第三个具体目标是测试HDAd是否可以在静脉旁路移植术的临床相关环境中实现动脉粥样硬化保护基因的持续表达。这三个目标的实现将使临床血管基因治疗更接近实施。此外，该目标的实现将建立新的实验动物模型和表达治疗基因的新载体平台。这些新的模型和载体将促进我们实验室和其他人开发预防和逆转人类血管疾病的基因疗法。

DESCRIPTION (provided by applicant): Atherosclerosis is a disease of the blood vessel wall that causes heart attacks, strokes, and loss of limbs. Despite major advances in medical and surgical management, atherosclerosis still causes significant morbidity and mortality. The impact of atherosclerosis on the health of the American people is expected to increase in the coming decades due to aging of the population and the consequences of the current obesity/diabetes epidemic. The broad, long-term objective of this project is to develop a novel therapy that decreases the morbidity and mortality of atherosclerosis. This novel therapy involves the introduction and expression of disease-preventing genes in the cells that line the blood vessel wall, and is appropriately termed "atheroprotective gene therapy". Blood vessels treated with atheroprotective gene therapy would not develop atherosclerosis because they have been genetically modified to resist the underlying biological processes that cause atherosclerosis, including inflammation and accumulation of fat deposits in the blood vessel wall. There are 3 specific aims, all of which are carried out in rabbits. The aims are focused on developing clinically useful atheroprotective gene therapy, delivered by a promising gene-transfer vector, "helper-dependent adenovirus" (HDAd). HDAd is an attractive vector for human gene therapy because it expresses therapeutic genes stably for years in animals (including nonhuman primates) and is relatively non-inflammatory. The 3 specific aims exploit the promise of HDAd to address critical issues in preclinical gene-therapy research: 1) demonstration of long-term efficacy and lack of toxicity in large animal models of human disease (Aims 1 and 3); and 2) achievement of transgene expression levels that are sufficiently high to treat and prevent chronic diseases while minimizing the need for infusion of large amount of vectors (Aim 2). The first specific aim uses 2 animal models of robust atherosclerotic lesion growth and a model of atherosclerosis regression to test whether expression of apolipoprotein A-I in arterial endothelial cells can prevent growth of new atherosclerotic lesions and promote regression of existing lesions. The second specific aim develops improved expression cassettes that allow HDAd to express therapeutic genes at higher, more stable levels, specifically in endothelial cells. The third specific aim tests whether HDAd can achieve persistent expression of an atheroprotective gene in the clinically relevant setting of venous bypass grafting. Accomplishment of these 3 aims will bring clinical vascular gene therapy closer to implementation. Moreover, achievement of the aims will establish new experimental animal models and novel vector platforms for expressing therapeutic genes. These new models and vectors will facilitate development-both by our laboratory and others-of gene-based therapies that prevent and reverse human vascular disease.