Therapeutic Delivery Platforms against Botulism

描述（由申请方提供）：肉毒杆菌神经毒素（BoNT）是对人类最有效的蛋白质毒素，是A类选择剂。BoNT有七种血清型（称为A-G）。目前的五血清型疫苗供应有限，并且没有批准的针对肉毒杆菌中毒的疗法。在对BoNT进入神经元的研究中，观察到霍乱毒素的B亚单位（CT B）以与未处理的细胞相同的效率进入BoNT中毒的神经元。由于霍乱毒素已被用于将异源蛋白递送到细胞中，因此将开发大肠杆菌（LTB）的热不稳定肠毒素的CT B或相关B亚基作为将治疗递送到BoNT中毒的神经元中的平台。R21组分是设计基于B亚基的平台以将异源货物递送到BoNT中毒的神经元的胞质溶胶中的概念验证。有三个目标：鉴定进入BoNT-中毒的神经元的最有效的B亚基，工程化货物-A2接头以组装到B亚基递送平台上，并确定B亚基平台是否可以将货物递送到BoNT-中毒的神经元中。R33组分将优化B亚基作为治疗。有三个目标：优化B亚基平台进入神经元，优化货物-A2接头以组装到B亚基平台上，并将泛血清型疗法递送到BoNT中毒的神经元中，并在BoNT中毒的小鼠中测试该疗法。该提案的完成将为肉毒杆菌中毒的治疗提供一个平台，该平台也可用作治疗其他传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.