Targeted Gene Therapy of Heart Failure Post Myocardial Infarction

项目摘要 心力衰竭（HF）仍然是一个严重的公共卫生问题，尽管最近的医学进步。目前 可用的药物仅针对HF的症状，因此迫切需要用于治愈性治疗的新方法。 基因治疗已被提出作为这样一种有前途的方法;不幸的是，许多候选基因， 如果全身给药将导致严重的临床副作用。此外，大量的交付损失 向脱靶器官的载体需要使用高的载体剂量， 病变组织部位。为了应对这些挑战，我们建议工程腺相关病毒（AAV） 可以特异性靶向心肌梗死（MI）后受损的心脏组织的载体。的关键科学 该项目的前提是观察到细胞外蛋白酶，特别是基质金属蛋白酶 在MI后受损的心脏组织中，MMPs升高。我们开发了一个蛋白酶平台- 可激活的AAV载体，其可响应MI后升高的MMP递送基因。有希望地，在 通过静脉注射，我们的工程化AAV载体能够实现显著改善的靶向基因， 靶向递送到体内患病心脏的高MMP区域，并且这种靶向递送伴随有 减少向非靶器官的输送。在这个R 01项目中，我们的目标是设计，建造和表征一个 用于HF治疗的改进的蛋白酶可激活的AAV载体组。在目标1中，我们将创建AAV载体， 可以针对心肌梗死后的不同疾病阶段。在aim 2中，我们将使用分子建模和结构建模。 研究AAV衣壳变体和进一步改进我们的载体设计的方法。在目标3中，我们将 使用体内分子成像来表征工程化载体的体内特异性， 心肌梗死后心脏MMP水平升高。最后，在目标4中，我们将测试使用 在MI诱导的HF的体内模型中使用蛋白酶可激活的AAV载体。总的来说，通过提高 为了获得用于靶心脏组织的AAV载体，我们的目标是（i）克服使用侵入性施用的需要， （ii）最大限度地减少对脱靶器官的递送，从而减少副作用以及减少对靶器官的依赖性。 达到治疗效果所需的总载体剂量，和（iii）减少任何剂量依赖性免疫反应， 对向量的响应。

PROJECT SUMMARY Heart failure (HF) remains a serious public health concern despite recent advances in medicine. Currently available drugs only address symptoms of HF, thus new approaches for curative therapies are sorely needed. Gene therapy has been proposed as one such promising approach; unfortunately, many candidate genes would lead to serious clinical side effects if delivered systemically. Additionally, considerable loss of delivery vectors to off-target organs require high vector doses to be used in order to achieve therapeutic effect at diseased tissue sites. To address these challenges, we propose to engineer adeno-associated virus (AAV) vectors that can specifically target cardiac tissue damaged after a myocardial infarction (MI). The key scientific premise of this project is the observation that extracellular proteases, specifically matrix metalloproteinases (MMPs) are elevated in damaged cardiac tissue post-MI. We have developed a platform of protease- activatable AAV vectors that can deliver genes in response to the MMPs elevated post-MI. Promisingly, upon intravenous injection, our engineered AAV vectors are able to achieve significantly improved targeted gene delivery to the high MMP region of the diseased heart in vivo, and this targeted delivery is accompanied by decreases in delivery to non-target organs. In this R01 project, we aim to design, build, and characterize an improved panel of protease-activatable AAV vectors for HF treatment. In aim 1, we will create AAV vectors that can target different disease stages post-MI. In aim 2, we will use molecular modeling and structural approaches to study the AAV capsid variants and to further improve our vector designs. Then in aim 3, we will use in vivo molecular imaging to characterize the in vivo specificity of the engineered vectors in relation to elevated MMP levels in the heart post-MI. Finally, in aim 4 we will test the therapeutic efficacy of using the protease-activatable AAV vectors in in vivo models of MI-induced HF. Overall, by improving the specificity of AAV vectors for target cardiac tissues, we aim to (i) overcome the need to use invasive administration strategies; (ii) minimize delivery to off-target organs, leading to decreased side effects as well as decreased overall vector dosage needed to achieve therapeutic effect, and (iii) reduce any dose-dependent immune responses against the vector.