Characterization of Botulinum Neurotoxin A Subtypes

描述（由申请人提供）：肉毒杆菌神经毒素（BoNTs）是已知的毒性最强的毒素，被归类为A类精选药剂。bont是人类肉毒杆菌中毒的病原体，被用作治疗无数神经疾病的有效药物。bont通常被细分为7种血清型（A - G）。近年来，基于核苷酸序列的差异，已经在大多数血清型中发现了几种亚型bont。BoNT/A有5种亚型（A1 - A5）。除了序列研究和显示显著功能差异的初步数据外，对BoNTs亚型的分子和细胞生物学研究很少。本研究项目的目的是表征和识别BoNT/A1-A5在体外和体内的分子和细胞生物学特性，并将亚型特异性生物学特性与结构特性联系起来。拟议的研究代表了三个实验室之间长期和富有成效的合作伙伴关系，这项应用的推动力是基于这些实验室在bont亚型上的最新进展，包括亚型在分子特征、动力学和中毒机制以及结构特征方面的差异。这一建议将验证五种BoNT/A亚型具有独特的体内毒性谱的总体假设。目的1将检验每个BoNT/A亚型具有不同的体外毒性特征的假设，并且重组BoNT/A亚型可以作为遗传修饰的源材料来定义功能特性。目的2将验证BoNTs/A1-A5具有不同的细胞进入动力学和体内毒性谱的假设。目的3将检验BoNT/A亚型在神经元细胞模型中具有独特的细胞运输机制的假设，以及BoNT/A亚型之间细胞运输和生物学特性的差异是由于毒素的特定结构差异。该项目产生的数据有可能改善基于BoNT的药物的临床治疗，因为需要具有靶向特性和更少副作用的新药物和改良药物。此外，毒素特性的表征将有助于未来开发针对所有BoNT/A亚型有效的靶向抗BoNT治疗方法。

DESCRIPTION (provided by applicant): Botulinum neurotoxins (BoNTs) are the most poisonous toxins known and are classified as Category A select agents. BoNTs are the causative agent of human botulism, and are used as efficacious pharmaceuticals for treatment of a myriad of neuronal diseases. BoNTs are conventionally subdivided into 7 serotypes (A - G). In recent years, several subtype BoNTs have been identified for most serotypes based on differences in nucleotide sequences. Five subtypes of BoNT/A (A1 - A5) are recognized. Apart from sequence studies and initial data indicating significant functional differences, little researh has been conducted on the molecular and cell biology of the subtype BoNTs. The goal of this research project is to characterize and discern the molecular and cell biology properties of the BoNT/A1-A5 in vitro and in vivo, and relate subtype specific biological characteristics to structural properties. The proposed studies represent a strong partnership among three laboratories with long term and productive collaborations, and the impetus for this application is based upon recent progress in these laboratories on the subtype BoNTs, including that the subtypes differ in molecular characteristics, kinetics and mechanisms of intoxication, and structural features. This proposal will test the overall hypothesis that the five BoNT/A subtypes possess unique in vivo toxicity profiles. Aim 1 will examine the hypothesis that each BoNT/A subtype possesses distinct in vitro toxicity characteristics, and that recombinant BoNT/A subtypes can be produced as source materials for genetic modifications to define functional properties. Aim 2 will test the hypothesis that BoNTs/A1-A5 have distinct cell entry kinetics and in vivo toxicity profiles. Aim 3 will examine the hypothesis that BoNT/A subtypes have unique cell trafficking mechanisms in neuronal cell models, and that the differences in cellular traffickig and biological properties between BoNT/A subtypes are due to specific structural differences of the toxins. The data resulting from this project have the potential to improve clinical treatments with BoNT based pharmaceuticals, as new and modified pharmaceuticals with targeted characteristics and fewer side effects will become necessary. In addition, the characterization of toxin properties will facilitate future developments of targeted anti-BoNT therapeutics that will b effective against all BoNT/A subtypes.