Anthrax

炭疽芽孢杆菌是一种革兰氏阳性、孢子形成的A类生物，已经被用作 美国的生物恐怖主义武器其主要毒力因子为致死毒素（LT）和水肿毒素（EDEMA） 毒素（ET）和抗吞噬胶囊。虽然一种有效的疫苗（Biothrax），主要由 保护性抗原（PA），在美国获得许可，需要免疫的一大部分人口短 需要一种新的疫苗，这种疫苗的反应原性较低，能够引起快速的保护性免疫反应。 反应 本项目的目标是从B中鉴定新的抗原。炭疽孢子（分项目I.1）和 营养细胞（子项目1.2），可以包括在一个新的炭疽疫苗。这些抗原的基因 克隆、表达为重组蛋白并测试保护活性。更好地了解和 可视化发芽的过程和位置，将开发一种新的小鼠模型，使用条件 在B中表达lux基因。炭疽病（分项目一）1）。宿主对B的免疫反应。炭疽抗原， 包括T细胞的作用和HLA类型的重要性，将使用受试者的血液/细胞进行表征 患有炭疽病或接种过疫苗的人（分项目1.2）。 尽管关于ET和LT的新结构信息的可用性，但关于它们的细胞作用或它们的生理活性知之甚少。 炭疽中的角色这些问题将在子项目1.3中通过探索细胞内的 ET和LT酶活性单独和一起的后果，以及阻断其活性的试剂的评价。 方面的影响.最后，一种新的炭疽免疫策略，粘膜-初免/胃肠外-加强模式， 将测试沙门氏菌活载体疫苗（子项目1.4）。通过这种方法，主机系统 用粘膜施用的减毒S.来自子项目的表达PA和/或其他抗原的伤寒杆菌 I.1和1.2，使得宿主对随后用PA（Biothrax）进行的肠胃外加强的反应将更强烈， 重组PA，或与来自孢子或营养细胞的其他新鉴定的抗原缀合的PA [Sub. 项目1.1和1.2]。 这项研究将由一组在微生物方面具有丰富经验的研究人员进行。 致病机理、抗原鉴定、动物模型、毒素机制和疫苗开发和测试。 交付物包括来自B的新抗原。炭疽，在鼠和NHP系统中测试，化合物与 可能阻碍或阻断个体死于炭疽的分子机制，以及一种新的小鼠成像模型 萌发和细菌分布。

Bacillus anthracis is a Gram-positive, spore-forming, Category A organism that has already been used as a weapon of bioterrorism in the US. Its principal virulence factors are two toxins, Lethal Toxin (LT) and Edema Toxin (ET) and an anti-phagocytic capsule. Although an efficacious vaccine (Biothrax), consisting primarily of Protective Antigen (PA), is licensed in the US, the need to immunize a large segment of the population on short notice in case of attack requires a new vaccine that is less reactogenic and able to elicit a rapid protective response. The objectives of this project are to identify new antigens from B. anthracis spores (Sub-Project I.1) and vegetative cells (Sub-Project 1.2) that can be included in a new anthrax vaccine. The genes for these antigens will be cloned, expressed as recombinant proteins and tested for protective activity. To understand better and visualize the process and location of germination, a new mouse model will be developed, using conditional expression of a lux gene in B. anthracis (Sub-Project I. 1). The host immune response to B. anthracis antigens, including the role of T cells and the importance of HLA type, will be characterized using blood/cells from subjects who have had anthrax or have been immunized with the vaccine (Sub-Project 1.2). Despite availability of new structural information on ET and LT, little is known about their cellular actions or roles in anthrax. These issues will be addressed in Sub-Project 1.3, by exploration of the intracellular consequences of ET and LT enzymatic activities, alone and together, and evaluation of reagents to block their effects. Finally, a novel strategy for anthrax immunity, the mucosal-prime/parenteral-boost paradigm using a Salmonella-based live vector vaccine, will be tested (Sub-Project 1.4). With this approach, the host system is primed with mucosally administered, attenuated S. Typhi expressing PA and/or other antigens from Sub-Projects I.1 and 1.2, so that the host response will be more vigorous to subsequent parenteral boosting with PA (Biothrax), recombinant PA, or PA conjugated to the other newly identified antigens from spores or vegetative cells [Sub- Projects 1.1 and 1.2]. This research will be carried out by a team of investigators who have extensive experience in microbial pathogenesis, antigen identification, animal models, toxin mechanisms, and vaccine development and testing. The deliverables include new antigens from B. anthracis, tested in murine and NHP systems, compounds with potential to impede or block the molecular mechanisms by which individuals die of anthrax, and a new mouse model for imaging germination and bacterial distribution.