Pyroglutamate Amyloid-beta as an Immunotherapeutic Target for Alzheimer's Disease

焦谷氨酸淀粉样蛋白-β作为阿尔茨海默病的免疫治疗靶点

• 批准号: 8531819
• 负责人: CYNTHIA A LEMERE
• 金额: $ 32.03万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8531819
• 关键词: Acute; Affinity; Age; Age-Months; Aging; Alzheimer' s Disease; Amino Acids; Amyloid; Amyloid beta-Protein; Amyloid deposition; Animal Model; Antibodies; Behavioral; Bilateral; Binding; Biochemical; Blood Vessels; Brain; Canis familiaris; Carotid Artery Ulcerating Plaque; Cerebrum; Charge; Cognitive; Cognitive deficits; Collaborations; Cyclization; Data; Deposition; Disease Progression; Enzyme-Linked Immunosorbent Assay; Enzymes; Excision; Female; Flow Cytometry; Germany; Glutamic Acid; Goals; Human; Hybridomas; Image Cytometry; Immune response; Immunotherapeutic agent; Immunotherapy; Impaired cognition; In Vitro; Inflammation; Injection of therapeutic agent; Intraperitoneal Injections; Label; Learning; Left; Length; Life; Measures; Memory; Microglia; Monoclonal Antibodies; Mus; N-terminal; Neonatal; Nerve Degeneration; Neurodegenerative Disorders; Outcome Measure; Passive Immunization; Pathogenesis; Peptide antibodies; Peptides; Phagocytosis; Play; Prevention; Proteins; Pyroglutamate; Reagent; Reporting; Resistance; Role; Seeds; Staging; Technical Expertise; Testing; Therapeutic; Tissues; Transgenic Mice; Walkers; Water; aged; cellular imaging; cytokine; experience; extracellular; glutaminyl-peptide cyclotransferase; improved; in vivo; male; mouse model; neurotoxic; nonhuman primate; pathological aging; prevent; protein aggregate; protein aggregation; response; synthetic peptide; therapeutic target; uptake

DESCRIPTION (provided by applicant): N-terminally-truncated and modified amyloid-beta (A¿) peptides are abundant in cerebral amyloid deposits in Alzheimer's disease (AD). Pyroglutamate A¿ is generated upon N-terminal truncation of A¿ followed by cyclization by glutaminyl cyclase to convert glutamic acid at residues 3 and 11 to pyroglutamate (A¿pE3 and A¿pE11). Both forms aggregate quickly, resist degradation, and are neurotoxic. It is unclear if either is present in initial A¿ deposition in plaques and blood vessels (i.e., acting as a seed for further deposition) or if they are modified later. However, Alzheimer's disease progression appears to correlate with the presence of A¿ pE peptide aggregates in brain. We hypothesize that pyroglutamate A¿ acts as a seed for A¿ deposition and accelerates inflammation, neurodegeneration and cognitive decline; therefore, targeted removal of this toxic species by immunotherapy will reduce A¿ deposition, inflammation and neuritic dystrophy, and protect against cognitive impairment without disturbing non-pathogenic A¿. We propose 4 Specific Aims. Aim 1: We will determine if intrahippocampal or intraperitoneal injections of A¿pE-containing mouse brain extracts enhance A¿ deposition, inflammation, neurodegeneration and cognitive decline in APP/PS1dE9 transgenic mice with aging in vivo. Aim 2: We will determine if early removal of pyroGlu A¿ prevents general A¿ plaque deposition and neuritic changes, and protects against cognitive decline by passively immunizing (i.p.) male APP/PS1dE9 tg mice with an anti-A¿N3pE mAb (07/1), an anti-A¿pE11 mAb, a general A¿ mAb (3A1), or PBS weekly from 4-12 mo of age, starting prior to plaque onset. Outcome measures: behavioral, biochemical, and neuropathological analyses. Aim 3: We will determine if removal of pyroGlu A¿ in late stage AD reduces total A¿ and neurodegeneration and improves cognitive deficits by passively immunizing (i.p.) female APP/PS1dE9 tg mice weekly from 12-16 mo of age, starting well after plaque onset. Antibodies and outcome measures are the same as in Aim 2. Aim 4: We will examine the immune response of microglia to pyroGlu A¿ mAbs in acute in vivo studies and in primary microglial cultures in vitro. Our collaborators at Probiodrug AG (Germany) will kindly provide us with 2 high-affinity, highly selective pyroGlu A¿ mAbs (anti- A¿ pE3 and anti-A¿pE11), synthetic A¿pE peptides, and brain extracts from their transgenic mouse models that accumulate pyroGlu-3 A¿ peptides. Our collaborators at the CND have generously provided the 3A1 general A¿ mAb hybridoma as a control. Importantly, my lab initiated this collaboration and has many years of experience investigating pyroGlu A¿ deposition, inflammation, and A¿ immunotherapy. The overall goal of our study is to determine whether pyroglutamate A¿ proteins (A¿pE3 and A¿pE11) are therapeutic targets for Alzheimer's disease and, whether clearance by immunotherapy specific for either pyroGlu A¿ species would be efficacious to prevent and/or treat AD.

描述（由申请人提供）：阿尔茨海默病（AD）的大脑淀粉样蛋白沉积物中富含N末端截短和修饰的淀粉样β（AQ）肽。焦谷氨酸 A 是在 A 的 N 端截短后生成的，然后通过谷氨酰胺酰环化酶环化，将残基 3 和 11 处的谷氨酸转化为焦谷氨酸（A pE3 和 A pE11）。这两种形式都可以快速聚集，抵抗降解，并且具有神经毒性。目前尚不清楚是否存在于斑块和血管中的初始 A¿ 沉积中（即，充当 A 的种子） 进一步沉积）或如果稍后修改。然而，阿尔茨海默病的进展似乎与大脑中 A¿pE 肽聚集体的存在相关。我们假设焦谷氨酸 A 是 A 沉积的种子，会加速炎症、神经退行性变和认知能力下降；因此，通过免疫疗法有针对性地去除这种有毒物质将减少A¿沉积、炎症和神经炎性营养不良，并在不干扰非致病性A¿的情况下防止认知障碍。我们提出 4 个具体目标。目标 1：我们将确定海马内或腹膜内注射含有 A¿pE 的小鼠大脑提取物是否会增强 APP/PS1dE9 转基因小鼠体内衰老过程中的 A 沉积、炎症、神经变性和认知能力下降。目标 2：我们将确定早期去除 PyroGlu A¿ 是否可以防止一般 A¿ 斑块沉积和神经炎变化，并通过使用抗 A¿ N3pE mAb (07/1)、抗 A¿ pE11 mAb、普通 A¿ mAb (3A1) 或 PBS 被动免疫 (i.p.) 雄性 APP/PS1dE9 tg 小鼠，每周从 4-12 个月开始，预防认知能力下降。 年龄，从斑块出现之前开始。结果测量：行为、生化和神经病理学分析。目标 3：我们将从 12-16 月龄开始每周对雌性 APP/PS1dE9 tg 小鼠进行被动免疫（腹腔注射），从斑块出现后开始，确定 AD 晚期去除 PyroGlu A¿ 是否会减少总 A¿ 和神经变性，并改善认知缺陷。抗体和结果测量与目标 2 中的相同。目标 4：我们将在急性体内研究和体外原代小胶质细胞培养物中检查小胶质细胞对 PyroGlu A¿ mAb 的免疫反应。 Probiodrug AG（德国）的合作者将为我们提供 2 种高亲和力、高选择性的pyroGlu A¿单克隆抗体（抗A¿pE3和抗A¡pE11）、合成A¿pE肽以及来自积累pyroGlu-3 A¿肽的转基因小鼠模型的脑提取物。我们在 CND 的合作者慷慨地提供了 3A1 通用 A¿ mAb 杂交瘤作为对照。重要的是，我的实验室发起了这项合作，并在研究pyroGlu A¿沉积、炎症和A¿免疫疗法方面拥有多年的经验。我们研究的总体目标是确定焦谷氨酸 A¿ 蛋白（A¿pE3 和 A¿pE11）是否是阿尔茨海默病的治疗靶点，以及通过针对焦谷氨酸 A¿ 物种的特异性免疫疗法清除是否可以有效预防和/或治疗 AD。