Exposporium determinants of Bacillus anthracis

性状（由申请方提供）;炭疽芽孢杆菌是一种形成内孢子的土壤微生物，是一种重要的人畜共患病原体。它作为一种潜在的生物恐怖主义制剂，令人严重关切。孢子是这种病原体的感染形式。孢子进入人类宿主的途径决定了所导致疾病的性质，皮肤、胃肠道或肺部。胃肠道和肺炭疽与高死亡率有关。B。炭疽孢子具有称为外孢壁的外层。这种气球状的外层包含孢子表面分子，这些分子构成了与宿主先天免疫系统最初相互作用的位点。外孢壁覆盖有毛发状绒毛层，主要由胶原样糖蛋白BclA组成。这种孢子外壁蛋白结合吞噬细胞上的受体，以促进孢子的吸收，并启动感染过程。虽然它在感染的初始阶段起着重要作用，但关于外孢壁层的组成，组装过程和功能知之甚少。我们所知道的关于孢子形成过程的大部分知识是通过枯草芽孢杆菌的生物化学和遗传学研究得知的，枯草芽孢杆菌是一种孢子缺乏外孢壁的模式细菌。 我们建议在B中研究外孢壁的组成。炭疽病与遗传和生物化学为重点的方法。在我的实验室开发的转座子诱变系统已经产生了一个潜在的孢子外壁，间隙，和外孢子衣突变体的集合。这些突变体将在本项目中进行表征。通过蛋白质组学方法和通过鉴定与孢子形成细胞中已知的外孢壁蛋白形成复合物的蛋白质来鉴定另外的外孢蛋白。除了鉴定孢子外壁基因及其产物外，鉴定孢子形成细胞中较大复合物中存在的蛋白质将使我们开始确定哪些蛋白质在孢子形成过程中相互作用，我们可以开始绘制孢子外壁组装过程中蛋白质的顺序。该项目将导致更好地了解B中的内生孢子成熟。炭疽杆菌，并将确定孢子的目标，可能证明有用的未来疫苗或治疗的发展。此外，许多形成内孢子的人类病原体具有孢子外壁，包括蜡状芽孢杆菌、产气荚膜梭菌和艰难梭菌，以及对B的孢子外壁的更详细的了解。炭疽病可能为这些其他重要的人类病原体的孢子生物学提供见解。

DESCRIPTION (provided by applicant); Bacillus anthracis is an endospore-forming, soil microorganism that is an important zoonotic pathogen. It is of significant concern as a potential bioterrorism agent. The spore is the infective form of this pathogen. The route by which the spore gains access to a human host defines the nature of the resulting disease, cutaneous, gastrointestinal, or pulmonary. Gastrointestinal and pulmonary anthrax are associated with high mortality rates. The B. anthracis spore possesses an outer layer referred to as the exosporium. This balloon-like outer layer contains the spore surface molecules that constitute the site of initial interactions with the host innate immune system. The exosporium is covered with a hair-like nap layer made up principally by the collagen-like glycoprotein BclA. This exosporium protein binds to receptors on phagocytic cells to promote uptake of the spores and which initiates the infectious process. Although it plays an important role in the initial stages of infection, very little is known regarding the composition, assembly process, and function of the exosporium layer. Much of what we know regarding the sporulation process was learned through biochemical and genetic studies of Bacillus subtilis, a model bacterium whose spores lack an exosporium. We propose to study exosporium composition in B. anthracis with a genetic and biochemical focused approach. A transposon mutagenesis system developed in my laboratory has produced a collection of potential exosporium, interspace, and outer spore coat mutants. These mutants will be characterized in this project. Additional outer spore proteins will be identified by a proteomic approach and by identification of proteins which form complexes with known exosporium proteins in sporulating cells. In addition to identifying exosporium genes and their products, identification of proteins present in larger complexes in sporulating cells will permit u to begin to determine which proteins interact in the sporulation process and we can begin to map the order of proteins in the exosporium assembly process. This project will lead to a better understanding of endospore maturation in B. anthracis and will identify spore targets that may prove useful for future vaccine or therapeutic development. In addition, a number of endospore-forming human pathogens possess exosporia, including Bacillus cereus, Clostridium perfringens, and Clostridium difficile and a more detailed understanding of the exosporium of B. anthracis may provide insights on spore biology for these other important human pathogens.