Exposporium determinants of Bacillus anthracis

炭疽杆菌的外孢决定因素

• 批准号: 8351883
• 负责人: GEORGE C. STEWART
• 金额: $ 18.53万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8351883
• 关键词: Affect; Anthrax disease; Bacillus (bacterium); Bacillus anthracis; Bacillus anthracis spore; Bacillus cereus; Bacillus subtilis; Bacteria; Biochemical; Biochemical Genetics; Biology; Bioterrorism; Cells; Clostridium; Clostridium difficile; Clostridium perfringens; Co-Immunoprecipitations; Collagen; Collection; Complex; Cutaneous; Dendritic Cells; Development; Diagnostic; Disease; DsRed; Evaluation; Event; Future; Gene Proteins; Genes; Genetic; Germination; Glycoproteins; Goals; Human; Immune Sera; Immune response; Immune system; Infection; Label; Laboratories; Lead; Learning; Location; Lung; Maps; Membrane Proteins; Methods; Modeling; Mutagenesis; Napping; Nature; Organism; Pathway interactions; Phagocytes; Play; Procedures; Process; Protein Binding; Proteins; Proteomics; Public Health; Reproduction spores; Role; Route; Site; Soil; Staging; Stratum Basale; Structure; Surface; System; Time; Virulence; Western Blotting; Work; biothreat; cytokine; gastrointestinal; hair-like nap; insight; interest; macrophage; member; microorganism; mortality; mutant; novel; pathogen; pathogenic bacteria; prevent; promoter; protein B; protein complex; protein expression; receptor; therapeutic development; therapeutic vaccine; uptake; vaccine development

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. PUBLIC HEALTH RELEVANCE: Bacillus anthracis is a spore-forming bacterium that causes anthrax and is important as a potential biothreat agent. The spore is the infectious form of the bacterium and is the center of the initial host interactions in the anthrax infectious process. Thi project will make use of genetic and biochemical approaches to characterize the exosporium, the outermost layer of the spore. The work will provide information that may be important in understanding the biology of this important pathogen and may identify targets for the future development of vaccines, therapeutics, or diagnostics against this organism.

描述（由申请人提供）；炭疽芽孢杆菌是一种形成内生孢子的土壤微生物，是一种重要的人畜共患病原体。作为潜在的生物恐怖分子，它受到了极大的关注。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产生的皮肤、胃肠道或肺部疾病的性质。胃肠道炭疽和肺炭疽与高死亡率相关。炭疽芽孢杆菌孢子具有称为外孢壁的外层。这种气球状的外层含有孢子表面分子，构成与宿主先天免疫系统初始相互作用的位点。孢子外表面覆盖着一层主要由胶原蛋白样糖蛋白 BclA 组成的毛发状绒毛层。这种孢子外蛋白与吞噬细胞上的受体结合，促进孢子的摄取并启动感染过程。尽管它在感染的初始阶段发挥着重要作用，但人们对外孢子层的组成、组装过程和功能知之甚少。我们对孢子形成过程的了解大部分是通过对枯草芽孢杆菌的生化和遗传学研究了解到的，枯草芽孢杆菌是一种模式细菌，其孢子缺乏外孢子壁。 我们建议通过遗传和生化重点方法研究炭疽芽孢杆菌的外孢子成分。我的实验室开发的转座子诱变系统产生了一系列潜在的外孢子、间隙和外孢子外壳突变体。这些突变体将在该项目中进行表征。额外的外孢子蛋白将通过蛋白质组学方法以及通过鉴定与产孢细胞中已知的外孢子蛋白形成复合物的蛋白质来鉴定。除了鉴定外孢子基因及其产物之外，鉴定孢子形成细胞中较大复合物中存在的蛋白质将使您能够开始确定哪些蛋白质在孢子形成过程中相互作用，并且我们可以开始绘制外孢子组装过程中蛋白质的顺序。该项目将有助于更好地了解炭疽芽孢杆菌内生孢子的成熟，并将确定可能对未来疫苗或治疗开发有用的孢子靶标。此外，许多形成内孢子的人类病原体都具有外孢子，包括蜡样芽孢杆菌、产气荚膜梭菌和艰难梭菌，对炭疽芽孢杆菌外孢子的更详细了解可能会为这些其他重要人类病原体的孢子生物学提供见解。 公共卫生相关性：炭疽杆菌是一种能引起炭疽的孢子形成细菌，是一种重要的潜在生物威胁因子。孢子是细菌的感染形式，是炭疽感染过程中初始宿主相互作用的中心。该项目将利用遗传和生化方法来表征孢子外层（孢子的最外层）。这项工作将提供对于理解这种重要病原体的生物学可能很重要的信息，并可能确定未来开发针对这种生物体的疫苗、治疗方法或诊断方法的目标。