Gene therapy for Alzheimer's disease using virally delivered Aβ variants

使用病毒传递的 Aβ 变体进行阿尔茨海默氏病的基因治疗

• 批准号: 10609343
• 负责人: JOANNA L JANKOWSKY
• 金额: $ 13.98万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10609343
• 关键词: APP-PS1; Aducanumab; Aftercare; Age; Alzheimer' s Disease; Alzheimer' s disease therapy; Amyloid; Amyloid beta-Protein; Antibodies; Biophysical Process; Birth; Brain; Cell membrane; Chromatography; Chronic; Data; Disease; Engineering; Extracellular Space; Gene Expression Profiling; Gene Transduction Agent; Genes; Half-Life; Histologic; In Vitro; Life; Memantine; Mus; Neuroimmune; Neurons; Outcome; Penetration; Peptides; Phase; Prevention; Preventive treatment; Reaction; Route; Spectrum Analysis; Technology; Testing; Therapeutic; Therapeutic Uses; Toxic effect; Variant; Viral; Work; adeno-associated viral vector; analytical method; cognitive function; comparison intervention; delivery vehicle; dosage; gamma secretase; gene therapy; in vivo; inhibitor; mouse model; novel; peptide drug; prevent; protein misfolding; response; tau Proteins

SUMMARY The continuing saga of anti-Ab antibody aducanumab has produced the first positive phase 3 outcome for Alzheimer's disease (AD) since memantine was approved in 2003. This promising, albeit controversial, result has breathed new life into the therapeutic potential for Ab-lowering strategies and legitimized the ongoing exploration of other means to chronically and safely mitigate Ab. Past work had shown that small peptide inhibitors can be readily tailored to prevent Ab aggregation, but in vivo delivery of peptide-based drugs was limited by short half-life and poor brain penetration. We have identified two Ab sequence variants that meet criteria for potential therapeutic use, as they 1) prevent aggregation of WT Ab in vitro, 2) promote disassembly of Ab existing fibrils, 3) mitigate toxicity of Ab oligomers, and importantly, 4) do not self-aggregate. To deliver these peptides in vivo, we have developed a novel mini-gene to express our variant peptides at the plasma membrane where they are released into the extracellular space by g-secretase cleavage. By packaging this minigene into an AAV vector that is injected into APP/PS1 mice, our pilot data show that viral expression of variant Ab lowers Ab load and delays plaque formation. The current proposal will build on these results through the following specific aims. First, we will decipher the biophysical mechanism of interactions between variant and wild type Aβ peptides. We will use analytical methods of CD spectroscopy, SEC chromatography, EM, and antibody profiling to define the structural mechanism by which our variants prevent/reverse aggregation of wild-type Ab. Second, we will determine how dosage, timing and route of variant Aβ administration influence efficacy in vivo. We will use viral strategies to compare interventional treatment after amyloid onset with preventative treatment starting at birth, determine the lowest effective ratio of variant:wild- type Ab needed to modify plaque formation and cognitive function, and test whether delivery through the CSF can match the effect of neuronal transduction. Third, we will interrogate the neuroimmune reaction to variant Aβ as an accomplice to plaque reduction. We will use histological and transcriptional profiling to assess whether a neuroimmune response to either the variant peptide or its AAV carrier contribute to plaque prevention in vivo, and if the neuroimmune response changes with age. Finally, we will test the potential for variant Aβ to slow AD aggregate seeding. We anticipate that variant Ab will slow seeding by AD Ab extracts, but will more importantly test whether variant Ab can assuage cross-seeding of tau in amyloid-bearing mice. If successful, this strategy for self-inhibition may also be applicable to other protein misfolding diseases where peptide treatments have been eschewed for technical reasons that can now be overcome through expression engineering and viral technology.

总结 抗Ab抗体aducanumab的持续佐贺已经产生了第一个阳性的3期结果， 自2003年美金刚被批准以来，阿尔茨海默病（AD）。这个有希望的，尽管有争议的结果 为降低Ab策略的治疗潜力注入了新的活力，并使正在进行的 探索其他方法来长期和安全地缓解Ab。过去的研究表明， 抑制剂可以很容易地定制，以防止抗体聚集，但在体内输送肽为基础的药物， 受半衰期短和脑渗透性差的限制。我们已经确定了两个Ab序列变体， 潜在治疗用途的标准，因为它们1）在体外防止WT Ab聚集，2）促进分解 3）减轻Ab寡聚物的毒性，并且重要的是，4）不自聚集。提供 这些肽在体内，我们已经开发了一种新的迷你基因表达我们的变体肽在血浆 它们在膜上通过G-分泌酶切割释放到细胞外空间。通过包装这个 我们的试验数据表明，将小基因导入注射入APP/PS1小鼠的AAV载体中， 变体Ab降低Ab负荷并延迟牙斑形成。目前的提案将以这些成果为基础 通过以下具体目标。首先，我们将破译生物物理机制之间的相互作用， 变体和野生型Aβ肽。我们将使用CD光谱，SEC色谱， EM和抗体分析，以确定我们的变体预防/逆转 野生型Ab的聚集。其次，我们将确定变异Aβ的剂量、时间和途径， 给药影响体内功效。我们将使用病毒策略比较介入治疗后， 淀粉样蛋白的发病与预防性治疗开始在出生时，确定最低的有效比例的变体：野生型， Ab型需要改变斑块形成和认知功能，并测试是否通过CSF递送 可以达到神经元转导的效果。第三，我们将询问对变异的神经免疫反应， Aβ作为斑块减少的帮凶。我们将使用组织学和转录谱来评估 对变体肽或其AAV载体的神经免疫应答是否有助于斑块 体内预防，以及神经免疫反应是否随年龄变化。最后，我们将测试 变体Aβ以减缓AD聚集体播种。我们预期变体Ab将减缓AD Ab提取物的接种， 但更重要的是测试变体Ab是否可以减轻携带淀粉样蛋白的小鼠中tau的交叉接种。如果 成功的，这种自我抑制的策略也可以适用于其他蛋白质错误折叠疾病， 由于技术原因，肽治疗一直被回避， 表达工程和病毒技术。