A platform for therapeutic agents that promote rapid recovery from botulism

促进肉毒杆菌中毒快速康复的治疗剂平台

• 批准号: 8323222
• 负责人: George A. Oyler
• 金额: $ 83.43万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8323222
• 关键词: Animal Model; Animal Testing; Animals; Antidotes; Binding; Blood; Bontoxilysin; Botulinum Toxin Type A; Botulism; Categories; Cells; Centers for Disease Control and Prevention (U.S.); Clostridium botulinum; Clostridium difficile; Cytosol; Development; Dose; Drug Delivery Systems; Drug Kinetics; Engineering; Evaluation; Exposure to; F Box Domain; Hand; Intoxication; Lead; Measures; Medical; Modeling; Modification; Molecular; Motor; Mus; Muscle function; Nature; Neurons; Oryctolagus cuniculus; Paralysed; Patients; Peptide Hydrolases; Pharmaceutical Preparations; Proteins; Recombinants; Recovery; Recovery of Function; Research; Risk; Route; SNAP receptor; Safety; Serotyping; Serum; Specificity; System; Testing; Therapeutic; Therapeutic Agents; Therapeutic Human Experimentation; Toxic effect; Toxin; base; biodefense; botulinum toxin type B; botulinum toxin type C; design; drug development; enzyme activity; enzyme substrate; innovation; mutant; nanobodies; neurotransmitter release; novel therapeutics; polypeptide; pre-clinical; programs; public health relevance; receptor; research clinical testing; restoration; safety testing; small molecule; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): Botulism is caused by exposure to toxins produced by Clostridium botulinum neurotoxin (BoNT), a CDC Category A biodefense threat agent for which no antidote currently exists. Seven different BoNT serotypes have been discovered to date (BoNT/A-G), many having numerous additional BoNT subtypes. To protect against all of these diverse BoNT bioterror threats, expensive conventional small molecule drug development would need to be separately performed for each of the seven different drug targets and perhaps others. This challenge, together with other extreme hurdles confronting BoNT small molecule drug development, particularly complicates efforts to develop small molecule drugs to treat botulism. New therapeutic paradigms are urgently needed to counter the enormous risks associated with these easy to obtain, easy to produce and extremely dangerous bioterror agents. We have developed and then extensively optimized two distinct 'designer E3-ligase' agents that each accelerate the 'molecular cure' of neurons intoxicated by one of the two most dangerous Botulinum neurotoxins, serotypes A or B (BoNT/A, BoNT/B). These two lead agents consist of the F-box domain of TrCP fused to a camelid 'nanobody' domain with binding specificity for one of the BoNT proteases. These polypeptide agents, with a size less than 30 kDa, bind to the BoNT protease and cause its rapid, intraneuronal destruction leading to rapid recovery of the neuron. Because of the modular nature of this antidote, it will be simple and straightforward to develop similar agents to treat all other BoNT serotypes and subtypes simply by substituting the nanobody domains with another having the appropriate specificity. In this proposal, we will develop a general delivery vehicle to deliver our two lead agents to the cytosol of intoxicated neurons within botulism patients and perform pre-clinical evaluation. As the vehicle, we propose to use an atoxic Clostridial toxin-based neuronal delivery vehicle (TNDV) due to its highly evolved capability to enter the body, survive in serum and deliver enzyme activities to the cytosol of targeted cells. We will develop three different and proven TNDV systems, each having unique and compelling features, and then select the best vehicle(s) for further development and animal testing. The three TNDV systems will be modified, atoxic forms of: 1) BoNT serotype C; 2) C. difficile toxin B and; 3) Clostridial C2 toxin. If successful, it is expected that similar agents could be developed to target the accelerated turnover of virtually any cytosolic neuronal protein for research or therapeutic applications. Public Health Relevance: Botulinum neurotoxin is an extremely dangerous, CDC Category A biodefense threat that is widely available, easily produced, exceedingly toxic and for which no antidote is available. Furthermore, at least seven different toxin types exist, each constituting of different drug targets and thus requiring distinct, challenging and expensive small molecule drug development programs. In contrast, the innovative new platform for biomolecule therapeutics that we propose to develop has the potential to quickly lead to commercially viable antidotes for all BoNT serotypes.

描述（由申请人提供）：肉毒杆菌中毒是由暴露于肉毒梭菌神经毒素（BoNT）产生的毒素引起的，肉毒梭菌神经毒素是CDC A类生物防御威胁剂，目前没有解毒剂。迄今为止，已经发现了七种不同的BoNT血清型（BoNT/A-G），其中许多具有许多另外的BoNT亚型。为了防止所有这些不同的BoNT生物恐怖威胁，昂贵的常规小分子药物开发需要分别针对七种不同的药物靶标中的每一种以及其他靶标进行。这一挑战以及BoNT小分子药物开发面临的其他极端障碍，特别是使开发小分子药物治疗肉毒杆菌中毒的努力复杂化。迫切需要新的治疗范例，以应对与这些容易获得、容易生产和极其危险的生物恐怖制剂相关的巨大风险。我们已经开发并广泛优化了两种不同的“设计者E3-连接酶”试剂，每种试剂都加速了两种最危险的肉毒杆菌神经毒素血清型A或B（BoNT/A，BoNT/B）之一中毒的神经元的“分子治愈”。这两种先导剂由融合至骆驼科动物“纳米抗体”结构域的TrCP的F-box结构域组成，所述结构域对BoNT蛋白酶之一具有结合特异性。这些大小小于30 kDa的多肽试剂与BoNT蛋白酶结合，并引起其快速的神经元内破坏，导致神经元的快速恢复。由于这种解毒剂的模块化性质，简单地通过用具有适当特异性的另一个结构域取代纳米抗体结构域来开发类似的药剂以治疗所有其他BoNT血清型和亚型将是简单和直接的。在这个提议中，我们将开发一种通用的递送载体，将我们的两种先导药物递送到肉毒中毒患者体内中毒神经元的胞质中，并进行临床前评估。作为媒介物，我们建议使用无毒梭菌毒素为基础的神经传递媒介物（TNDV），由于其高度进化的能力，进入体内，在血清中生存，并提供酶活性的细胞质的靶细胞。我们将开发三种不同的、经过验证的TNDV系统，每种系统都具有独特和引人注目的功能，然后选择最好的载体进行进一步的开发和动物试验。三个TNDV系统将被修改，无毒形式：1）BoNT血清型C; 2）C.艰难梭菌毒素B和; 3）梭菌C2毒素。如果成功的话，预计可以开发类似的试剂来靶向几乎任何细胞溶质神经元蛋白的加速周转，用于研究或治疗应用。 公共卫生相关性：肉毒杆菌神经毒素是一种极其危险的CDC A类生物防御威胁，广泛存在，易于生产，毒性极强，并且没有解毒剂。此外，存在至少七种不同的毒素类型，每种毒素类型由不同的药物靶标组成，因此需要不同的、具有挑战性的和昂贵的小分子药物开发计划。相比之下，我们建议开发的生物分子治疗的创新新平台有可能快速导致所有BoNT血清型的商业上可行的解毒剂。