Novel brain endothelial-targeted gene therapy vectors to treat neuroinflammatory disease

炎症性中枢神经系统（CNS）疾病，如多发性硬化症（MS），往往是无法治愈的，治疗方案往往是不令人满意的。治疗性基因转移可能是应对这一挑战的新策略。然而，与大多数其他潜在的基因治疗应用一样，缺乏有效和特异性转导感兴趣组织的载体是这种奋进的主要障碍。脑微血管系统在神经炎症的病理生物学中占据中心地位。因此，它可能是治疗干预的高度相关靶点。基于从肽展示文库中选择靶向腺相关病毒（AAV）载体的创新方法，我们开发了一种新型AAV载体，其在体内全身静脉内给药后以前所未有的功效和特异性转导脑微血管（BR 1-AAV载体）。在这里提出的项目中，我们将通过优化二级文库选择程序来表征和进一步改进BR 1-AAV的靶向病毒衣壳。随后，我们将使用这种脑内皮靶向载体作为多发性硬化症的实验性疾病模型来治疗实验性自身免疫性脑脊髓炎（EAE）。神经炎症性疾病的标志是血脑屏障（BBB）紧密连接（TJ）完整性的丧失、免疫细胞对中枢神经系统的浸润和血管周围病变的发展。为了打断这一点，我们将使用BR 1-AAV衍生物来1.）赋予CCL 2 7 ND的脑血管表达，CCL 2 7 ND是被认为在神经炎症中至关重要的趋化因子CCL 2的显性阴性变体; 2.）敲低脑血管内皮细胞上的CCL 2受体CCR 2以防止BBB TJ破坏并抑制CCL 2分泌到血液中; 3.）通过TJ蛋白claudin-1的内皮表达来稳定BBB TJ。该项目可能建立BR 1-AAV衍生载体作为研究和治疗各种神经炎症和潜在的其他CNS疾病的工具。

Inflammatory central nervous system (CNS) disease like multiple sclerosis (MS) is often incurable and treatment options are frequently unsatisfactory. Therapeutic gene transfer may be a novel strategy to meet this challenge. However, like in most other potential gene therapy applications, the lack of vectors efficiently and specifically transducing the tissue of interest is the main obstacle for this endeavor. The brain microvasculature takes center stage in the pathobiology of neuroinflammation. Thus it may be a highly relevant target for therapeutic intervention. Based on an innovative approach for the selection of targeted adeno-associated viral (AAV) vectors from peptide display libraries, we have developed a novel AAV vector that transduces brain microvasculature with unprecedented efficacy and specificity after systemic intravenous administration in vivo (BR1-AAV vector). In the project proposed here, we will characterize and further improve the targeted viral capsid of BR1-AAV by subjecting it to an optimizing secondary library selection procedure. Subsequently, we will use this brain endothelium-targeted vector to treat experimental autoimmune encephalomyelitis (EAE) as an experimental disease model of MS. Hallmarks of neuroinflammatory diseases are loss of blood brain barrier (BBB) tight junction (TJ) integrity, CNS infiltration by immune cells and development of perivascular lesions. To interrupt this, we will use BR1-AAV derivatives to 1.) confer brain vascular expression of CCL2 7ND, a dominant negative variant of the chemokine CCL2 that is considered to be crucial in neuroinflammation; 2.) to knock down the CCL2 receptor CCR2 on brain vascular endothelial cells to prevent BBB TJ disruption and inhibit CCL2 secretion into the blood; 3.) to stabilize BBB TJs by endothlial expression of the TJ protein claudin-1. This project may establish BR1-AAV-derived vectors as tools to study and treat a wide variety of neuroinflammatory and potentially other CNS diseases.