Novel Reengineered Microbiome-based Biologic Therapy to Treat Cognitive and Behavioral Symptoms of Alzheimer's Disease and Related Dementias

摘要 我们的早期ADDP提案旨在开发一种新型基因工程细菌生物制品来治疗 阿尔茨海默病（AD）最常见的早期症状，包括认知障碍和其他 神经心理学症状，如焦虑和抑郁。这种使人衰弱的疾病给我们带来了巨大的 对社会造成情感、社会和经济负担。没有有效的疾病修饰AD药物存在，以抑制 与疾病进展相关的A β和tau蛋白病。目前FDA批准的胆碱能药物和 多巴胺能神经疗法在挽救轻度认知障碍（MCI）的记忆方面最多是非常温和的 以及AD病例的前驱期或早期阶段，并且常常恶化焦虑、冷漠、抑郁、激越和其他症状。 神经行为症状胃肠道刺激甚至死亡最近的生物学证据表明，AD是一种 神经回路紊乱认知和行为症状的发作和进展涉及以下缺陷： 单胺神经递质信号网络，包括去甲肾上腺素（NE）和多巴胺（DA）。因此我们 我认为，恢复大脑DA/NE输入具有很好的潜力，是一种有效的方法，以减轻 认知和行为缺陷，甚至可以延迟疾病的发作。目前，口服片剂给药的L- 多巴/卡比多巴3 - 4次/天仍然是恢复人类大脑DA/NE水平的最有效疗法。 然而，这种重复的慢性脉动输送会导致严重的副作用。因此，我们的治疗假设 解决这一未解决的临床问题的方法是全身递送遗传工程化的L-DOPA细菌活细胞， LDBL治疗剂（LDBL）将避免血浆L-DOPA的大的波动，并提供更一致的L-DOPA递送。 多巴恢复DA/NE到稳定的水平，更好地缓解AD症状，没有额外的副作用 方面的影响.我们的概念验证数据支持1）基因工程益生菌E。coliNissle1917菌株 （EcNL-DOPA）在体外和体内均有效地产生L-DOPA，2）EcNL-DOPA的口服给药容易地定殖于 小鼠肠道，达到稳态血浆L-DOPA水平，其对应于临床有效血浆 水平，并增加啮齿动物和犬科动物脑中的L-DOPA和DA/NE水平，以及3）EcNL-DOPA 在AD动物模型中，治疗可改善神经行为结果并降低A β水平，包括 犬齿我们正在申请专利的ADDP战略的总体目标是优化领先的LDBL和测试 其在减轻早期AD的认知和行为缺陷（例如冷漠）方面的临床前功效。 为了实现这一目标，我们将追求以下具体目标：（i）优化用于动物试验的铅LDBL，（ii） 评价用于临床前疗效研究的先导LDBL的长期药代动力学（PK）和安全性特征， (iii)确定两种铅LDBL在转基因（Tg）AD啮齿动物模型中的体内药效学（PD）功效， 和（iv）评估最有效的铅LDBL在痴呆犬模型中的功效。一起，我们独特的 涉及益生菌L-DOPA的长期递送的治疗管道策略预计将建立一条新的管道 基于工程微生物群的单胺神经治疗模式用于AD相关痴呆（ADRD）。

Abstract Our early-stage ADDP proposal aims to develop a novel genetically engineered bacterial biologic to treat the most common early symptoms of Alzheimer's disease (AD), including cognitive impairment and other neuropsychological symptoms, such as anxiety and depression. This debilitating disease imposes a huge emotional, social and financial burden on society. No effective disease-modifying AD drug exists to dampen the Aβ and tau proteinopathies associated with disease progression. Current FDA-approved cholinergic and glutamatergic neurotherapeutics are very modest at best in rescuing memory in mild cognitive impairment (MCI) and prodromal or early stages of AD cases, and often worsen anxiety, apathy, depression, agitation, and other neurobehavioral symptoms, GI irritations, and even mortality. Recent biological evidence indicates that AD is a neural circuit disorder. The onset and progression of cognitive and behavioral symptoms involve a deficiency in monoamine neurotransmitter signaling networks, including norepinephrine (NE) and dopamine (DA). Thus, we propose that restoring brain DA/NE inputs holds the excellent potential to be an effective approach to alleviating cognitive and behavioral deficits in AD and could even delay disease onset. Currently, oral tablet dosing of L- DOPA/carbidopa 3-4 times/day remains the most effective therapy at restoring brain DA/NE levels in humans. However, this repeated chronic pulsatile delivery causes severe side effects. Thus, our therapeutic hypothesis to address this unmet clinical problem is that systemic delivery of genetically engineered L-DOPA bacterial live- therapeutics (LDBL) will avoid large fluctuations in plasma L-DOPA and provide more consistent delivery of L- DOPA to the brain for restoring DA/NE to stable levels that better relieve AD symptoms without additional side effects. Our proof-of-concept data support that 1) the genetically engineered probiotic E. coli Nissle 1917 strains (EcNL-DOPA) efficiently produce L-DOPA both in vitro and in vivo, 2) oral dosing of EcNL-DOPA readily colonizes the mouse gut, achieves a steady-state plasma L-DOPA level that corresponds to the clinically effective plasma level in humans, and increases L-DOPA and DA/NE levels in the brain of rodents and canines, and 3) EcNL-DOPA treatment leads to improved neurobehavioral outcomes and reduces Aβ levels in AD animal models including canines. The overarching goal of our patent-pending ADDP strategy is to optimize the lead LDBL and test its preclinical efficacy in alleviating the cognitive and behavioral deficits, such as apathy, of early AD. To achieve this goal, we will pursue the following specific aims: (i) Optimize the lead LDBL for animal testing, (ii) Evaluate the chronic pharmacokinetic (PK), and safety profile of the lead LDBLs for preclinical efficacy studies, (iii) Determine in vivo pharmacodynamic (PD) efficacy of two lead LDBLs in transgenic (Tg) AD rodent models, and (iv) Assess the efficacy of the most effective lead LDBL in canine models of dementia. Together, our unique therapeutic pipeline strategy involving chronic delivery of probiotic L-DOPA is expected to establish a new line of engineered microbiome-based monoamine neurotherapeutic modalities for AD-related dementias (ADRD).