Mechanisms by which B. anthracis Spores Escape the Lung

炭疽芽孢杆菌孢子逃逸肺部的机制

• 批准号: 8874829
• 负责人: JORDAN PATRICK METCALF
• 金额: $ 30.98万
• 依托单位: OKLAHOMA MEDICAL RESEARCH FOUNDATION
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8874829
• 关键词: Address; Alveolar; Alveolar Macrophages; Alveolus; Animal Model; Anthrax disease; Antibodies; Antibody Response; Antigens; Bacillus anthracis; Bacillus anthracis spore; Bacteria; Binding; Biological Assay; Bioterrorism; Blood Circulation; Breathing; Cell Line; Cell physiology; Cells; Cessation of life; Dendritic Cells; Disease; Edema; Enzyme-Linked Immunosorbent Assay; Epithelial; Epithelial Cells; Flow Cytometry; Goals; Grant; Host Defense Mechanism; Human; Immune response; Immunologics; Immunosuppression; Individual; Infection; Intervention; Lead; Lung; Lymphatic; Mediating; Membrane; Modeling; Molecular; Papio; Participant; Phagocytes; Phagocytosis; Phase; Play; Population; Predisposition; Process; Reproduction spores; Resistance; Role; Sentinel; Series; Site; Staging; Structure of lymph node of thorax; Surface; Symptoms; Systemic disease; Systemic infection; Testing; Toxin; Treatment Efficacy; Vaccine Production; Vaccines; anthrax lethal factor; anthrax toxin; anthrax toxin receptors; base; cell type; edema factor; immunosuppressed; in vitro Model; inhibiting antibody; insight; killings; lymph nodes; lymphatic duct; novel; pathogen; programs; protective effect; receptor; research study; response; weapons

Inhalational anthrax is the most lethal form of the disease, and the form that occurs when spores ofthe causative agent, 6. anthracis is used as a weapon of bioterror. Uniquely, vegetative bacteria of S. anthracis do not cause disease at the site of entry. Instead spores are taken up by resident lung cells and carried through lymphatic ducts to the thoracic lymph nodes (TLN). From TLN the pathogen disseminates to cause the lethal terminal phase of the disease. There are many unanswered questions about this deadly disease. It is not known what cells take the pathogen out of the lung to the TLN. Most importantly, it is not known what role Ba toxins (lethal toxin, LT; edema toxin, ET) play in this process, and how antibodies to the cellular binding component of these toxins (protective antigen, PA) protect the host. The goal of this proposal is to answer these questions. In the last granting period we determined that in contrast to the prevailing thought, human alveolar macrophages (HAM) do not express cellular receptors for the toxins and are resistant to immunosuppressive effects of LT. We also found that the cells that line the point of entry of the pathogen, alveolar epithelial cells, express anthrax toxin receptors, and are susceptible to the effects of toxin. Toxin decreases barrier function of these cells, which could facilitate escape of the pathogen from the alveolar compartment of the lung. We have characterized three types of human lung dendritic cells (DCs). We hypothesize that one of these is the carrier cell for 6. anthracis, and is unable to kill the pathogen due to toxin. In Aim 1, we will determine which DCs phagocytose and kill spores, the killing mechanism, and their immune response to spores. In Aim 2, we will determine whether these cells contain toxin receptors, are immunosuppressed by toxins, and how toxins inhibit, and antibody to PA promotes, killing of pathogen, and the mechanisms involved. In Aim 3 we will determine whether toxins facilitate carrier cell-assisted, or cell-unassisted escape from the alveolus in an in vitro model. We will also test the role of the carrier cell, and the effect of PA antibody in host protection in a baboon inhalation anthrax model developed by our colleague. Dr. Lupu. Our experiments should confirm whether one site of protective activity of antibodies to PA is in the initial interactions between DCs of the lung and the pathogen. If this is the case, then we should be able to use the results to develop in vitro models to determine efficacy of the antibody response to vaccines. We will also provide new avenues for intervention in this disease.

吸入性炭疽是该疾病的最致命形式，而当孢子的孢子的形式发生 病原体，6。炭疽病被用作生物植物的武器。独特的是炭疽链霉菌的营养细菌 不要在进入现场引起疾病。相反，孢子被驻留的肺部细胞接收并携带 通过淋巴管到胸腔淋巴结（TLN）。从TLN病原体传播以引起 疾病的致命末端阶段。 关于这种致命疾病有许多未解决的问题。尚不知道哪些细胞接受 病原体从肺部到TLN。最重要的是，尚不知道什么作用Ba毒素（致命毒素，LT； 在此过程中，水肿毒素等在此过程中发挥作用，以及这些毒素的细胞结合成分的抗体 （保护性抗原，宾夕法尼亚州）保护宿主。该建议的目的是回答这些问题。在最后 我们确定，与人类肺泡巨噬细胞相比 （HAM）不表达毒素的细胞受体，并且对LT的免疫抑制作用具有抗性。 我们还发现，在病原体的进入点肺泡上皮细胞的细胞表达 炭疽毒素受体，并且容易受到毒素的影响。毒素降低了这些的障碍功能 可以促进病原体从肺部肺泡室逸出的细胞。 我们表征了三种类型的人肺树突状细胞（DC）。我们假设其中之一 是6个炭疽菌的载体细胞，由于毒素而无法杀死病原体。在AIM 1中，我们将确定 DCS吞噬吞噬并杀死孢子，杀戮机制及其对孢子的免疫反应。目标 2，我们将确定这些细胞是否含有毒素受体，由毒素免疫抑制，以及如何 毒素抑制PA的抗体促进，杀死病原体以及所涉及的机制。在目标3中我们 将确定毒素是促进载体细胞辅助的，还是从肺泡中脱离肺泡 体外模型。我们还将测试载体电池的作用，以及PA抗体在宿主保护中的作用 我们的同事开发的狒狒吸入炭疽模型。卢普博士。我们的实验应该确认 抗PA抗体的保护活性位点是否在肺DC之间的初始相互作用中 和病原体。如果是这种情况，那么我们应该能够使用结果来开发体外模型 确定抗体对疫苗的疗效。我们还将为干预这种疾病提供新的途径。