Immunity to Bacillus anthracis: Spore-Host Interactions

描述（由申请人提供）： 该计划项目的总体目标是充分了解炭疽芽孢杆菌孢子-宿主相互作用的机制，以促进炭疽病预防，干预和诊断程序的设计和开发。我们将确定糖蛋白和其他孢子外壳决定因子的详细化学结构，并研究它们作为新B的可能性。炭疽孢子的具体目标，炭疽预防和治疗。外孢壁的详细组成将通过遗传和生化策略来表征。所有已知的和待发现的外孢壁组分的个体突变将被制造。外孢壁的碳水化合物组分的结构将使用多种遗传、化学和光谱方法来确定。将使用小鼠模型识别孢子进入和通过气道、胃肠道、皮肤和血液途径的细胞途径。通过基因靶向使先天和适应性免疫系统的选定基因失活的小鼠将用于定义宿主中未萌发孢子的免疫病理学和免疫逃避机制。野生型和突变孢子将用于确定这些组分在哺乳动物宿主中孢子完整性、孢子萌发和存活中的作用。我们将使用孢子、重组孢子外壁成分和确定的碳水化合物作为这些受体的配体来分离和表征宿主细胞上的孢子受体。 此外，该项目还将涉及构建碳水化合物-蛋白质缀合物和基于我们的结构研究设计的新糖蛋白。除了克隆和表达的重组外孢壁蛋白外，这些构建体将用于增强对B的外孢壁上的糖缀合物的免疫应答。炭疽病，并协助开发新的疫苗或干预战略，将优化特定的保护性初级和二级免疫反应，并可能导致新的战略封锁孢子进入宿主。我们的总体策略与目前使用的策略不同，目前使用的策略旨在诱导对B植物体产生的毒素的保护性免疫。炭疽孢子侵入宿主体内并萌发后，我们将能够确定潜在的机制，迅速消灭孢子之前，建立感染位点和营养细胞生长。这种性质的治疗药物将是目前推荐的抗生素治疗方案的主要补充，或在多药耐药B的情况下。炭疽菌株被改造以产生额外的毒素用作生物武器。

DESCRIPTION (provided by applicant): The overall objective of this program project is to provide sufficient understanding of the mechanisms of Bacillus anthracis spore-host interactions to facilitate the design and development of preventive, interventive and diagnostic procedures for the disease Anthrax. We will determine the detailed chemical structure of glycoproteins and other spore coat determinants and investigate the possibility that they can be used as new B. anthracis spore-specific targets for anthrax prevention and treatment. The detailed composition of the exosporium will be characterized by genetic and biochemical strategies. Individual mutations of all known, and to be discovered, exosporium components will be made. The structure of the carbohydrate components of the exosporium will be determined using a variety of genetic, chemical and spectroscopic methods. A mouse model will be used to identify the cellular pathways of spore entry and passage via the airways, gastrointestinal, cutaneous, and blood routes. Mice in which selected genes of the innate and adaptive immune system have been inactivated by gene-targeting will be used to define mechanisms of immunopathology and immune evasion of the ungerminated spores in the host. Wild type and mutant spores will be used to determine the role of these components in spore integrity, spore germination and survival in a mammalian host. We will isolate and characterize spore-receptors on host cells using spores, recombinant exosporium components and defined carbohydrates as ligands for these receptors. In addition, this project will also involve the construction of carbohydrate-protein conjugates and neoglycoproteins designed on the basis of our structural studies. These constructs, in addition to cloned and expressed recombinant exosporium proteins, will be used to enhance immune responses to the glycoconjugates on the exosporium of B. anthracis, and assist in the development of novel vaccine or interventional strategies that will optimize specific protective primary and secondary immune responses, and may lead to new strategies for blockade of spore entry into the host. Our overall strategy differs from that currently in use which is designed to induce protective immunity to the toxins elaborated by the vegetative form of B. anthracis after spore invasion and germination in the host. We will be able to identify potential mechanisms to rapidly inactivate spores prior to establishment of infectious loci and vegetative cell outgrowth. Therapeutic drugs of this nature would be a major supplement to the current recommended antibiotic regimens or in the case of multidrug-resistant B. anthracis strains engineered to produce additional toxins for use as bioweapons.