Use of super-resolution microscopy to visualize the interaction between Alzheimer therapeutic antibodies and Aβ aggregates

使用超分辨率显微镜可视化阿尔茨海默病治疗抗体和 Aβ 聚集体之间的相互作用

• 批准号: 10360508
• 负责人: Ladan Amin
• 金额: $ 16.5万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10360508
• 关键词: Aducanumab; Affect; Age; Alzheimer' s Disease; Alzheimer' s disease pathology; Alzheimer' s disease therapeutic; Amyloid beta-Protein; Antibodies; Binding; Binding Sites; Biochemical; Biochemical Process; Biological Assay; Brain; Cell Surface Receptors; Characteristics; Clinical; Clinical Trials; Color; Data; Disease; Elderly; Failure; Functional disorder; Goals; Growth; Image; Immunotherapeutic agent; Individual; Kinetics; Laboratories; Ligands; Lipids; Measures; Memory Loss; Microscopy; Modeling; Molecular; Molecular Conformation; Monoclonal Antibodies; Nerve Degeneration; Neurodegenerative Disorders; Neuronal Dysfunction; Neurons; Pathologic; Patients; Persons; Pharmacological Treatment; Phase; Polymers; Population; PrP; Process; Proteins; Reporting; Resolution; Signal Transduction; Signal Transduction Pathway; Structure; Surface; Synapses; Techniques; Testing; Therapeutic Monoclonal Antibodies; Therapeutic antibodies; Therapy Clinical Trials; Toxic effect; Work; abeta accumulation; abeta oligomer; base; clinically relevant; design; experimental study; improved; inhibitor; insight; multidisciplinary; nanoscale; neurotoxic; novel therapeutics; polymerization; prevent; receptor; secretase; single molecule; success

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects millions of people worldwide. Current pharmacological treatments for AD are symptomatic and ineffective, and clinical trials of therapies based on anti-Aβ monoclonal antibodies (mAbs) or secretase inhibitors have been disappointing. One reason for the recent failures of anti-Aβ therapies, even those begun presymptomatically, is that the Aβ assemblies that accumulate in AD are conformationally diverse, and currently available mAbs do not target the primary neurotoxic species. Therefore, it is critical to thoroughly characterize the molecular mechanisms by which therapeutic mAbs interact with Aβ and influence its assembly, structure, and toxicity. It is presumed that AD pathology starts by the binding of neurotoxic Aβ oligomers (Aβo) to receptor proteins or lipids on the surface of neurons, resulting ultimately in synaptic dysfunction and degeneration. In previous studies, we have used super-resolution microscopy to directly visualize β-receptor interactions at the nanometer scale. We find that one documented Aβ receptor, the cellular prion protein, PrPC, specifically inhibits the polymerization of Aβ fibrils via a unique mechanism in which it binds specifically to the rapidly growing end of each fibril, thereby blocking polarized elongation at that end. PrPC binds neurotoxic oligomers and protofibrils in a similar fashion, suggesting that it may recognize a common, end-specific, structural motif on all of these assemblies. Additional experiments suggest that two other previously described Aβ receptors (FcγRIIb, and LilrB2) act in a similar fashion. Taken together, our results suggest that neurotoxic signaling by several different receptors may be activated by common molecular interactions with both fibrillar and oligomeric Aβ ligands. The experimental approach used in these studies opens up the possibility of probing the mechanism of action of other agents that affect Aβ polymerization or toxicity, in particular anti-Aβ mAbs such as those currently undergoing extensive testing in clinical trials. In this application, we propose to characterize the mechanism of action of four clinical stage antibodies (aducanumab, gantenerumab, bapineuzumab and solanezumab), as well as a panel of conformation-dependent antibodies that recognize oligomeric, pre-fibrillar, and fibrillar forms of Aβ. First, we will measure the effect of these mAbs on Aβ aggregation processes using biochemical assays. Then, we will take advantage of single molecule, SRM to determine the localization of the mAbs on the individual Aβ aggregates. In addition, we will directly measure fibril elongation rates, as well as primary and secondary nucleation processes, in the presence and absence of each mAb. Finally, we will determine how these mAbs affect the interaction between Aβ and three of its documented receptor proteins; PrPC, FcγRIIb, and LilrB2. This proposal will lay the groundwork for the design of improved mAbs that selectively alter specific steps in the Aβ assembly process, and that block the interaction of oligomeric aggregates with cell surface receptors that transduce their neurotoxic effects.

阿尔茨海默病（AD）是一种影响数百万人的进行性神经退行性疾病