Therapeutic delivery of single chain antibody for Alzheimer's disease

描述(申请人提供)：阿尔茨海默病(AD)是60岁后最常见的痴呆症原因。阿尔茨海默病的病理特征包括神经炎性斑块和脑血管内淀粉样多肽的沉积、神经原纤维缠结和神经元丢失。越来越多的证据支持A？及其前体在AD发病机制中起重要作用的观点。用人工合成的A免疫AD小鼠模型，可减少A的沉积，减轻记忆和学习障碍。然而，最近的临床试验由于脑部炎症而暂停，推测是由T细胞和/或FC介导的免疫反应引起的。在AD小鼠模型中，外周注射抗A？抗体也可以清除先前存在的淀粉样斑块，这表明主动的T细胞介导的免疫反应是不必要的。局部应用F(ab‘)2而不使用抗A抗体Fc导致AD小鼠模型中淀粉样蛋白沉积的清除，表明非Fc介导的机制参与了清除。虽然这些被动免疫方案在治疗AD患者时可能是有效的，但不会引起炎症反应等副作用，但这些方案会反复注射抗体，给AD患者带来巨大的经济和身体负担。我们假设抗A？的单链抗体(ScFv)在治疗AD小鼠模型中是有效和安全的。我们建议使用三种不同血清型的重组腺相关病毒(RAAV)载体来优化抗A？scFv传递在降低脑A？负荷和改善行为缺陷方面的效果。这项研究将作为一个原则证明，证明这种基因治疗方式是否可以将抗A？scFv传递到许多大脑区域，以减少A？负荷，并改善AD模型小鼠的学习和记忆障碍。将实现以下具体目标，以优化抗A？单链抗体的预防和治疗输送。在目标1中，我们将评估一次脑室注射rAAV1、rAAV8或AAV9编码的抗A？scFv在C57BL/6小鼠体内的表达和细胞毒性，以优化抗A？scFv的脑内递送。在目的2中，我们将在AD小鼠模型中评价优化的编码抗A？scFv的rAAV的脑室注射的预防和治疗效果。我们利用神经病理、生化、免疫学和行为分析来确定该方法的预防和治疗效果及安全性。长期目标是为开发安全有效的抗AD抗体递送系统奠定逻辑基础。痴呆症(AD)是导致老年人痴呆症的最常见原因。然而，到目前为止，还没有令人满意的治疗AD的方法。这项研究将作为原则的证明，以证明我们用于治疗性抗体输送的新型免疫基因治疗方式是否在治疗AD动物模型中有效。公共卫生

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is the most common cause of dementia after the age of 60. The pathological hallmarks of AD include deposition of amyloid ¿-peptide (A¿) in neuritic plaques and cerebral blood vessels, neurofibrillary tangles, and loss of neurons. Increasing evidence supports the notion that A¿ and its precursor play important roles in the pathogenesis of AD. Immunization of mouse models of AD with synthetic A¿ reduces A¿ deposits and attenuates their memory and learning deficits. Recent clinical trials, however, were halted due to brain inflammation, presumably induced by T-cell mediated and/or Fc-mediated immune responses. Peripheral administration of antibodies against A¿ also induced clearance of preexisting amyloid plaques in AD mouse models, indicating that an active T-cell-mediated immune response is unnecessary. Topical application of the F(ab')2 without Fc of antibodies against A¿ led to clearance of amyloid deposits in an AD mouse model, indicating that non-Fc-mediated mechanisms are involved in the clearance. Although these passive immunization modalities may be effective in treating AD patients without inducing side effects such as inflammatory responses, such modalities suffer from repeated administrations of antibodies, leading to a large financial and physical burden to AD patients. We hypothesize that single chain antibodies (scFvs) against A¿ are effective and safe in treating AD mouse models. We propose to optimize the efficacy of anti-A¿ scFv delivery in reducing cerebral A¿ load and improving behavioral deficits using three deferent serotypes of recombinant adeno-associated virus (rAAV) vectors encoding anti-A¿ scFv. This study will serve as a proof of principle to demonstrate if this gene therapy modality can deliver anti-A¿ scFvs to many brain regions to reduce A¿ load and improve learning and memory deficits in AD model mice. The following specific aims will be carried out in order to optimize prophylactic and therapeutic delivery of anti-A¿ scFv. In Aim 1, we will evaluate expression and cytotoxicity of scFv delivery by a single intracerebroventricular injection of rAAV1, rAAV8, or AAV9 encoding anti-A¿ scFv in C57BL/6 mice to optimize intracranial delivery of anti-A¿ scFv. In Aim 2, we will evaluate prophylactic and therapeutic effects of intracerebroventricular injections of optimized rAAV encoding anti-A¿ scFv in an AD mouse model. We utilize neuropathological, biochemical, immunological, and behavioral analyses to determine the prophylactic and therapeutic effects and safety of the modality. The long-term goal is to establish the logical basis for developing safe and effective delivery systems of anti-A¿ antibody for AD. Project De isease (AD) is the most common cause of dementia in the elderly. To date, however, no satisfactory treatments are available for AD. This study will serve as a proof of principle to demonstrate if our novel immune gene therapy modality for therapeutic antibody delivery is effective in treating an animal model of AD. Public Hea