Germination of Bacillus anthracis Spores in Macrophages

炭疽芽孢杆菌孢子在巨噬细胞中的萌发

• 批准号: 6685480
• 负责人: DAOGUO ZHOU
• 金额: $ 22.5万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6685480
• 关键词: Bacillus anthracis; antibacterial antibody; bacteria infection mechanism; bacterial capsules; bacterial cytopathogenic effect; bacterial genetics; bioterrorism /chemical warfare; cell surface receptors; fluorescence microscopy; host organism interaction; intracellular transport; laboratory rabbit; macrophage; mannose 6 phosphate; microorganism culture; molecular rearrangement; phagocytosis; plasmids; polymerase chain reaction; spores; transfection /expression vector; transposon /insertion element; vesicle /vacuole

DESCRIPTION (provided by applicant): Anthrax is caused by the inhalation, ingestion or uptake through a cut or abrasion of spores of Bacillus anthracis. An essential step in B. anthracis pathogenesis is the transformation of metabolically dormant spores into vegetative, toxin-producing bacteria. Past research has primarily focused on the mechanism of macrophage killing by anthrax toxins. Recent studies have begun to explore factors that are responsible for the germination of B. anthracis spores and their subsequent survival in the macrophages. The spores are engulfed by macrophages where they germinate and commence the synthesis of toxins. Subsequent release from macrophages leads to proliferation in the blood of vegetative bacteria and extensive toxin production. Spore germination within the macrophage is a critical but not well-understood step in the infection process. It is not currently known which vacuolar compartment or spore properties are essential for germination. Our working hypothesis is that germination requires a specific endosomal/phagosomal compartment with appropriate physical and nutritional factors recognized by engulfed spores from pathogenic isolates and that germination requires specific receptors and/or specific spore surface properties. In order to test this hypothesis, we propose two approaches: 1) initially direct or limit spores to different phagosomal compartments and then block vacuole rearrangement at distinct steps in order to examine the effects on spore uptake and germination. 2) Select for macrophage-specific, germination deficient spores and thus identify spore components essential for intracellular germination. Results from our study will define the compartment of the vacuoles required for B. anthracis germination, and the macrophage-specific germination-deficient B.anthracis mutants should help to elucidate spore components essential for germination in macrophages. These results will advance our understanding of in vivo spore germination and the properties of B. anthracis spores necessary for this process. This information could be helpful for developing pharmaceutical agents useful for preventing the germination of B. anthracis spores inside macrophages.

描述（由申请人提供）：炭疽是由吸入、摄入或通过切割或磨损炭疽芽孢杆菌孢子引起的。 B中的重要一步。炭疽病的发病机制是代谢休眠孢子转化为营养的产毒素细菌。 过去的研究主要集中在炭疽毒素杀死巨噬细胞的机制。 最近的研究已经开始探索导致B发芽的因素。炭疽孢子及其随后在巨噬细胞中的存活。 孢子被巨噬细胞吞噬，在那里它们发芽并开始合成毒素。 随后从巨噬细胞释放导致营养细菌在血液中增殖并产生大量毒素。 巨噬细胞内的孢子萌发是感染过程中的关键但尚未充分理解的步骤。 目前尚不清楚哪种液泡室或孢子特性对萌发至关重要。 我们的工作假设是，发芽需要一个特定的内体/吞噬体隔室与适当的物理和营养因素，从病原性分离物的吞噬孢子的认可，发芽需要特定的受体和/或特定的孢子表面特性。 为了验证这一假设，我们提出了两种方法：1）最初将孢子引导或限制在不同的吞噬体隔室中，然后在不同的步骤中阻断液泡重排，以检查对孢子摄取和萌发的影响。 2)选择巨噬细胞特异性的萌发缺陷孢子，从而鉴定细胞内萌发所必需的孢子组分。 我们的研究结果将确定B所需的空泡区室。炭疽芽孢杆菌萌发，巨噬细胞特异性萌发缺陷型B.炭疽突变体应有助于阐明孢子在巨噬细胞中萌发所必需的成分。 这些结果将进一步加深我们对体内孢子萌发和B性质的理解。炭疽孢子是这一过程所必需的。 这些信息可能有助于开发可用于防止B萌发的药剂。巨噬细胞内的炭疽孢子