Therapeutic Delivery Platforms against Botulism

描述（由申请人提供）：肉毒杆菌神经毒素（BoNTs）是对人类和A类精选剂最有效的蛋白质毒素。bont有七种血清型（称为A-G）。目前的五血清型疫苗供应有限，并且没有针对肉毒杆菌中毒的批准治疗方法。在对BoNT进入神经元的研究中，观察到霍乱毒素（CTB）的B亚基进入BoNT中毒的神经元的效率与未处理的细胞相同。由于霍乱毒素已被用于将异源蛋白递送到细胞中，CTB或大肠杆菌热不稳定肠毒素（LTB）的相关B亚基将被开发为将治疗递送到bont中毒神经元的平台。R21组件是一个概念证明，可以设计一个基于B亚基的平台，将异种货物输送到BoNT中毒神经元的细胞质中。有三个目标：确定进入bont中毒神经元的最有效的B亚基，设计一个货物- a2连接器组装到B亚基输送平台上，并确定B亚基平台是否可以将货物输送到bont中毒神经元中。R33成分将优化B亚基作为一种疗法。有3个目标：优化B亚基平台进入神经元的入口，优化货物- a2连接子组装到B亚基平台上，并将泛血清型治疗方法传递到bont中毒的神经元中，并在bont中毒的小鼠中测试这种治疗方法。这项建议的完成将为肉毒杆菌中毒治疗提供一个平台，也可能作为治疗其他感染性神经系统疾病和神经系统疾病的递送平台。

DESCRIPTION (provided by applicant): The botulinum neurotoxins (BoNTs) are the most potent protein toxins for humans and Category A select agents. There are seven serotypes of the BoNTs (termed A-G). The current penta-serotype vaccine is in limited supply and there are no approved therapies against botulism. During studies on BoNT entry into neurons, the B subunit of cholera toxin (CTB) was observed to enter BoNT-intoxicated neurons with the same efficiency as untreated cells. Since cholera toxin has been used to deliver heterologous proteins into cells, CTB or a related B subunit of the heat-labile enterotoxins of Escherichia coli (LTB) wil be developed as a platform to deliver therapies into BoNT-intoxicated neurons. The R21 component is a proof of concept to engineer a B subunit-based platform to deliver a heterologous cargo into the cytosol of a BoNT- intoxicated neuron. There are three aims: identify the most efficient B subunit for entry into BoNT-intoxicated neurons, engineer a cargo-A2 linker to assemble onto the B subunit delivery platform, and determine if the B subunit platform can deliver cargo into a BoNT-intoxicated neuron. The R33 component will optimize the B subunit as a therapy. There are 3 aims: optimize entry of the B subunit platform into neurons, optimize the cargo-A2 linker for assembly onto the B subunit platform, and deliver a pan-serotype therapy into a BoNT-intoxicated neuron and test this therapy in BoNT-intoxicated mice. Completion of this proposal will provide a platform for therapies against botulism that may also be useful as a delivery platform to treat other infectious neurological diseases and diseases of the nervous system. PUBLIC HEALTH RELEVANCE: The botulinum neurotoxins (BoNTs) are the most toxic proteins for humans. The determination that the B subunit of cholera toxin enters BoNT-intoxicated neurons provides a basis to develop a platform to deliver therapies to treat BoNT-intoxicated cells to reverse the paralysis associated with botulism. This platform may also have utility to deliver therapies against other neurological diseases.