Bordetella adenylate cyclase toxin: the role of cell interaction in toxin functio

博德特氏菌腺苷酸环化酶毒素：细胞相互作用在毒素功能中的作用

基本信息

批准号：
8486374
负责人：
Joshua Clark Eby
金额：
$ 12.98万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-01 至 2014-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8486374
关键词：
Accounting Adenylate Cyclase Adenylate Cyclase Toxin Affect Age Animals Antibodies Apical Award Bacteria Bacterial Proteins Bacterial Toxins Basic Science Binding Biological Assay Bordetella Bordetella pertussis CD11 Antigens Calmodulin Catalytic Domain Cell Communication Cell Death Cell membrane Cells Chemicals Chinese Hamster Ovary Cell Collaborations Complement Cyclic AMP Cytolysis Data Development Disease Energy Transfer Enzymes Epithelial Epithelial Cells Epithelium Erythrocytes Family Generations Hemolysis Human Hybrids ITGAM gene ITGB2 gene In Vitro Infection Inflammatory Integrins Intoxication Investigation Knowledge Learning Light Lipid Bilayers Lipids Lung diseases Measurement Measures Membrane Mentors Methods Mutation Oligosaccharides Pathogenesis Pertussis Prevention Relative (related person)Research Personnel Resources Respiratory Tract Infections Role Scientist Sheep Small Interfering RNA Structure Structure of respiratory epithelium Surface Techniques Testing Toxin United States Universities Uropathogenic E. coli Virginia Virulence Factors apical membrane basolateral membrane cell type crosslink cytokine experience in vivo interest macrophage member monolayer mutant neutrophil novel pathogenic bacteria polypeptide prevent receptor respiratory scorpion toxin I&apos &apos

项目摘要

DESCRIPTION (provided by applicant): The adenylate cyclase toxin (AC toxin) is necessary for disease caused by Bordetella pertussis, which has reemerged in the United States over the last two decades. AC toxin is expressed by seven of eight species of Bordetella which cause respiratory disease in humans and a range of animals. The toxin molecule is a unique hybrid of an adenylate cyclase enzyme and a binding domain homologous to the repeats-in-toxin (RTX) family of pore-forming bacterial protein toxins. AC toxin intoxicates host cells by binding to the cell membrane and translocating its catalytic domain across the lipid-bilayer, resulting in unregulated generation of intracellular cAMP. Prevention of translocation by an antibody to the catalytic domain or by certain mutations will enhance the other major function of the toxin, formation of oligomeric pores which cause lysis of erythrocytes and contribute to non-apoptotic cell death of macrophages. The magnitude of intoxication correlates with the relative surface expression of the (32 integrin, CD11b/CD18, a receptor expressed most abundantly on neutrophils and macrophages; however, the relationship between AC toxin and CD11b/CD18 is not well defined. Our preliminary data show that CD11b/CD18 does not simply increase sensitivity of cells to intoxication, but, when high concentrations of toxin are applied to cells, actually limits intoxication while possibly enhancing oligomer formation. We will investigate the basic mechanisms of the interaction between AC toxin and CD11 b/CD18. The determinants of toxin binding and function may explain a novel finding: cells of an epithelial monolayer are insensitive to intoxication by AC toxin applied to the apical surface, surprising because the toxin can intoxicate all cell types so far tested, and important because the bacterium first encounters these cells upon infection. These studies will shed light upon the mechanism of pore formation by bacterial toxins, and the pathogenesis of disease caused by all Bordetellae. The proposed project will continue my interest in basic science that began at the age of 19. My mentor, Dr. Erik Hewlett, with over 25 years of experience" studying Bordetella pertussis, is a preeminent scientist in the field of bacterial toxins. His emphasis on learning through scientific collaboration will complement my plan for structured coursework. The K08 award, in combination with the resources of my mentor and the University of Virginia, will provide me with the support necessary for my full development as a clinician scientist. RELEVANCE: AC toxin is expressed by seven of the eight species of Bordetella and is also a member of the RTX family of pore-forming bacterial protein toxins that are produced by other pathogenic bacteria such as uropathogenic Escherichia coli. Here, we will characterize the basic mechanisms of cell binding by AC toxin and show that these mechanisms affect the function of the toxin and determine its role as a virulence factor.

描述（由申请人提供）：腺苷酸环化酶毒素（AC毒素）对于由百日咳Bordetella引起的疾病是必需的，在过去的二十年中，该疾病在美国重新出现。 AC毒素由八种Bordetella中的七种表达，它们在人类和一系列动物中引起呼吸道疾病。毒素分子是腺苷酸环化酶酶的独特杂交，也是与重复的毒素（RTX）家族同源的结合结构域的形成孔形成细菌蛋白毒素。 AC毒素通过与细胞膜结合并在整个脂质双层中迁移其催化结构域来陶醉宿主细胞，从而导致细胞内cAMP的产生不受管制。预防抗催化结构域或某些突变的抗体易位将增强毒素的其他主要功能，形成的寡聚孔，从而导致红细胞裂解并导致巨噬细胞的非凋亡细胞死亡。中毒的大小与（32整合蛋白，CD11b/cd18，一种受体表达最多的受体表达相关，但是在中性粒细胞和巨噬细胞上表达最多；但是，AC毒素和CD11b/cd18之间的关系并不是很好地确定cd11b/cd18的浓度。细胞实际上限制了中毒，同时我们将研究AC毒素和CD11 B/CD18之间相互作用的基本机制细菌首先在感染后遇到这些细胞。拟议的项目将继续我对19岁开始的基础科学的兴趣。我的导师埃里克·惠普（Erik Hewlett）拥有25年的经验。“研究Bordetella tertussis，是细菌毒素领域的杰出科学家。他通过科学的协作将我与K08奖一起提供的奖励的计划补充。我作为临床科学家的完整发展所必需的。相关性：AC毒素由八种Bordetella种中的七种表达，也是由其他致病细菌（如尿素疾病性埃塞里希菌大肠杆菌）产生的RTX家族的成员。在这里，我们将表征AC毒素通过AC毒素结合的基本机制，并表明这些机制会影响毒素的功能，并确定其作为毒力因子的作用。