WGA as a Novel Vehicle for Intranasal Delivery of an Anti-A-beta Antibody in AD

描述(申请人提供)：本申请是对PAS-10-151(阿尔茨海默病药物发现补助金(R21))的回应。需要新的载体来有效地将免疫治疗药物直接输送到大脑，以便最大限度地发挥被动免疫治疗、延迟或预防阿尔茨海默病(AD)的功效。阿尔茨海默病目前正困扰着500万美国人。结合凝集素，小麦胚凝集素(WGA)，已被证明通过以下方式增加候选药物的鼻内摄取和促进直接给药：(1)吸附或受体介导的内吞作用进入嗅觉神经元(OSN)，然后细胞内转运到嗅球；(Ii)非特异性液体相内吞进入OSN，然后细胞内转运到嗅球；和/或(Iii)沿着嗅球间上皮裂隙的细胞外扩散，直接到达嗅球和/或脑脊液。在阿尔茨海默病转基因小鼠模型的临床前研究和早期人类临床试验中，静脉注射单抗被动免疫已显示出可喜的结果，如降低大脑A和稳定或预防认知缺陷。然而，抗体在大脑中的渗透水平受到血脑屏障(BBB)的限制。此外，在患有血管淀粉样蛋白的小鼠和人类中，血液中高水平的抗Ass抗体已导致微出血和血管源性水肿。该项目旨在通过使用WGA载体蛋白的鼻腔途径最大限度地发挥抗A抗体的效力来克服这些限制。本项目将测试WGA作为一种新型载体的有效性，它不仅将增强抗A？mAb 3A1的输送，这种抗体凭借其内吞吸收的优势与单/二聚体和纤维状ASs(由Lemere-Consulting提供)结合，而且由于其鼻黏膜样生化成分，还将促进3A1的被动扩散，最大限度地提高鼻腔被动免疫的免疫治疗效果，将在阿尔茨海默病5XFAD模型中进行测试。假设：鼻腔注射WGA结合的3A1单抗和未标记的3A1抗体将最大限度地发挥鼻腔被动免疫的免疫治疗潜力，改善5XFAD转基因小鼠的AD样病理认知改变。具体目的：[1]野生型小鼠鼻内注射WGA-3A1抗体后的脑内转运，以及3A1-WGA与5XFAD小鼠和人类AD小鼠脑内Ass斑块的结合。[2]确定WGA偶联的3A1单抗与未标记的3A1抗体联合鼻腔被动免疫是否能预防幼龄5XFAD斑块前期小鼠的AD样病理认知改变。[3]确定WGA偶联的3A1单抗与未标记的3A1抗体联合鼻腔被动免疫是否会减轻老年晚期斑块形成的5XFAD小鼠的AD样病理认知改变。包括转基因小鼠在内的所有资源和所需的专业知识都已准备好开始这项研究。意义：该项目将评估一种新的递送系统，将免疫疗法直接靶向大脑，从而推动最有希望的延缓或预防AD进展的疗法之一。 与公共卫生相关：阿尔茨海默病(AD)影响着500万美国人，但目前还没有长期的预防或治疗方法来减缓或治愈这种毁灭性的神经退行性疾病。该项目的目标是通过鼻-脑屏障将Ass抗体直接传递到脑内，从而提高Ass免疫疗法治疗AD的有效性和安全性。如果在小鼠身上成功，这种非侵入性的方法可能会转化为人类临床试验。

DESCRIPTION (provided by applicant): This application is in response to PAS-10-151 {Grants for Alzheimer's Disease Drug Discovery (R21)}. Novel vehicles are needed to effectively target direct delivery of immunotherapeutics to the brain in order to maximize the efficacy of passive immunization for treating, delaying or preventing Alzheimer's disease (AD), a disease that currently afflicts >5 million Americans. Conjugation of the lectin, Wheat Germ Agglutinin (WGA), has been shown to enhance intranasal uptake of candidate drugs and promote direct delivery to brain via (i) Adsorptive or receptor-mediated endocytosis into the olfactory sensory neurons (OSN) followed by intracellular transport to olfactory bulb; (ii) Non-specific fluid phase endocytosis into the OSNs followed by intracellular transport to olfactory bulb; and/or (iii) Extracellular diffusion along the inter-olfactory epithelial clefts directly to the olfactory bulb and/or CSF. Passive immunization by intravenous injection of A¿ monoclonal antibodies (mAb) has shown promising results such as lowering of cerebral A¿ and stabilization or prevention of cognitive deficits in preclinical studies in transgenic mouse models of AD and in early human clinical trials. However, the level of antibody penetration in the brain is limited by the blood-brain-barrier (BBB). In addition, in mice and humans with vascular amyloid, high levels of anti-Ass antibodies in blood has led to microhemorrhage and vasogenic edema. This project aims to overcome such limitations by maximizing the efficacy of the intranasal route of anti-A¿ antibody delivery using a WGA carrier protein. This project will test the efficacy of WGA as a novel vehicle that will not only enhance delivery of anti-A¿ mAb, 3A1, that binds to mono/dimers and fibrillar Ass (To be provided by Dr. Lemere-Consultant) by virtue of its endocytic uptake preference, but will also facilitate passive diffusion of 3A1 due to its nasal mucosa-like biochemical composition, maximizing immunotherapeutic efficacy of intranasal passive immunization, to be tested in Alzheimer's 5XFAD model. Hypothesis: Intranasal delivery of WGA-conjugated 3A1 mAb combined with unlabeled 3A1 antibody will maximize the immunotherapeutic potential of intranasal passive immunization ameliorating AD-like patho-cognitive changes in 5XFAD transgenic mice. Specific Aims: [1] Trafficking of WGA-3A1 antibody after intranasal delivery to the brain in wild type mice and binding of 3A1-WGA to Ass plaques in the brains of 5XFAD mice and human AD. [2] Determining if intranasal passive immunization with WGA-conjugated 3A1 mAb combined with unlabeled 3A1 antibody will prevent AD-like patho-cognitive changes in young pre-plaque 5XFAD mice. [3] Determining if intranasal passive immunization with WGA-conjugated 3A1 mAB combined with unlabeled 3A1 antibody will attenuate AD-like patho-cognitive changes in old late-stage plaque-bearing 5XFAD mice. All resources, including transgenic mice, and required expertise are ready to begin this study. Significance: This project will evaluate a novel delivery system to target immunotherapeutics directly to the brain, and thus advance one of the most promising therapies for delaying the progression or prevention of AD. PUBLIC HEALTH RELEVANCE: Alzheimer's disease (AD) affects >5 million Americans and yet there is no long-term prevention or treatment to slow the progression or cure this devastating neurodegenerative disease. The goal of this project is to improve the efficacy and safety of Ass immunotherapy for AD by enhancing direct delivery of Ass antibodies to brain via the nose-brain barrier. If successful in mice, this non-invasive methodology could be translated to human clinical trials.