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)，通常是无法治愈的，治疗方案往往不令人满意。治疗性基因转移可能是应对这一挑战的一种新策略。然而，像大多数其他潜在的基因治疗应用一样，缺乏有效和特定地转导感兴趣组织的载体是这一努力的主要障碍。脑微血管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一个高度相关的靶点。基于从多肽展示文库中筛选靶向腺相关病毒(AAV)载体的创新方法，我们开发了一种体内全身静脉给药后具有前所未有的有效性和特异性的转导脑微血管的AAV载体(BR1-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鉴定和进一步改进BR1-AAV的靶向病毒衣壳。随后，我们将使用这种脑内皮靶向载体治疗实验性自身免疫性脑脊髓炎(EAE)，作为MS的实验性疾病模型。神经炎性疾病的特征是血脑屏障(BBB)紧密连接(TJ)完整性丧失，免疫细胞对中枢神经系统的渗透，以及血管周围病变的发展。为了中断这一点，我们将使用BR1-AAV导数为1。)使脑血管表达CCL2 7ND，这是趋化因子CCL2的显性负变异体，被认为在神经炎症中起关键作用；敲除脑血管内皮细胞表面CCL2受体CCR2，防止BBB TJ破坏，抑制CCL2分泌入血；通过内皮细胞表达TJ蛋白claudin-1来稳定BBB TJ。该项目可能会建立BR1-AAV衍生载体，作为研究和治疗多种神经炎性疾病和潜在的其他中枢神经系统疾病的工具。

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.