Therapeutic Delivery Platforms against Botulism

描述(申请人提供)：肉毒杆菌神经毒素(BoNTs)是对人类和A类精选药物最有效的蛋白质毒素。BoNTs有七种血清型(称为A-G)。目前的五血清型疫苗供应有限，而且还没有被批准的治疗肉毒杆菌中毒的方法。在BONT进入神经元的研究中，观察到霍乱毒素B亚单位(CTB)以与未处理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来将异源蛋白输送到细胞内，CTB或相关的不耐热大肠杆菌肠毒素(LTB)的B亚单位将被开发为一个平台，将治疗传递到Bont中毒的神经元。R21组分是一个概念验证，可以设计一个基于B亚单位的平台，将异源货物运送到Bont中毒神经元的胞浆中。有三个目的：确定进入Bont中毒神经元的最有效的B亚基，设计一个Cargo-A2连接子组装到B亚基传递平台上，以及确定B亚基平台是否可以将货物传递到Bont中毒的神经元。R33成分将优化B亚基作为一种疗法。有三个目标：优化B亚基平台进入神经元，优化Cargo-A2连接子以组装到B亚基平台上，并将泛血清型疗法输送到BONT中毒的神经元中，并在BONT中毒的小鼠身上测试这种疗法。这项提案的完成将为肉毒杆菌中毒的治疗提供一个平台，也可能作为治疗其他感染性神经疾病和神经系统疾病的交付平台。

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.