Staphylococcus aureus extracellular vesicles: host-pathogen interactions

金黄色葡萄球菌细胞外囊泡：宿主-病原体相互作用

• 批准号: 10001443
• 负责人: Jean Claire Lee
• 金额: $ 54.32万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10001443
• 关键词: Animals; Autolysin; Bacteria; Bacterial Adhesins; Biochemistry; Biogenesis; Biological; CASP1 gene; Cations; Cell physiology; Cell surface; Cells; Cellular biology; Communities; Cytolysins; Cytoplasmic Protein; Cytotoxin; Data; Detection; Disease; Electron Microscopy; Encapsulated; Environment; Eukaryota; Excretory function; Generations; Genetic; Genus staphylococcus; Goals; Gram-Negative Bacteria; Gram-Positive Bacteria; Host Defense; Human; Immune; Immune Evasion; Immunology; In Vitro; Infection; Inflammasome; Inflammatory Response; Innate Immune Response; Interleukin-1 beta; Interleukin-18; Investigation; Knowledge; Lead; Life; Lipids; Lipoprotein (a); Lipoproteins; Mammalian Cell; Mediator of activation protein; Membrane; Microbial Physiology; Modeling; Molecular Biology; Mus; Nucleic Acids; Outcome; Pathogenesis; Pathway interactions; Peptide Hydrolases; Peptidoglycan; Phenols; Play; Polysaccharides; Process; Production; Proteins; Research; Role; Signal Transduction; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus aureus infection; Superantigens; Surface; System; TLR2 gene; Tissues; Toxin; Vesicle; Virulence; Virulence Factors; base; biological adaptation to stress; capsule; cell type; crosslink; cytotoxic; extracellular; extracellular vesicles; fungus; host colonization; human disease; in vivo; insight; intercellular communication; interdisciplinary approach; macrophage; methicillin resistant Staphylococcus aureus; microbial; nanosized; novel; pathogen; pathogenic bacteria; skin lesion; trait; transmission process; uptake; vesicular release

Project Summary/Abstract Staphylococcus aureus is an important bacterial pathogen that provokes a diverse range of human diseases, ranging from mild skin lesions to invasive and life-threatening infections. The virulence traits that characterize S. aureus include surface adhesins and glycopolymers, as well as secreted proteins, such as cytolysins, superantigens, and proteases, many of which play vital roles in immune evasion. S. aureus also produces nano- sized, spherical, bilayered, extracellular membrane vesicles (EVs) with distinct biologic activities. The production of EVs represents a secretory pathway common to mammalian cells, fungi, and bacteria that allows for cell-free intercellular communication, but the mechanisms underlying EV biogenesis in Gram-positive bacteria are poorly understood. S. aureus EVs encapsulate cargo that includes surface adhesins, lipoproteins, capsular polysaccharides, and exoproteins, including proteases and pore-forming toxins, which have been shown to play roles in bacterial virulence and the transmission of biologic signals to host cells. The overall goal of this project is to gain a better understanding of the biological role that S. aureus EVs play in the pathogenesis of staphylococcal infections. The project hypothesis is that EVs modulate bacterial pathogenesis by serving as a novel secretory pathway for S. aureus to transport toxins, cytoplasmic proteins, and lipoproteins and deliver them into host cells, while protecting the cargo from detection or destruction by the external environment. Preliminary data indicate that S. aureus EVs package an array of virulence factors, are taken up by macrophages, and are cytotoxic for a variety of host cells. Moreover, S. aureus EVs induce cleavage of caspase-1 and release of mature IL-1β and IL-18 in human macrophages in a lipoprotein-dependent manner. These results highlight the role of EVs in inflammasome activation, an important intracellular immune pathway that has been shown to play a crucial role in determining the outcome of S. aureus infections. Specific mechanisms whereby EVs are generated and the downstream effects of EV release from the bacterial cell are goals of this proposal. The specific aims of this application are to: (1) elucidate the mechanisms underlying EV biogenesis in S. aureus and the role of EVs in the SA cellular release of cytoplasmic proteins, lipoproteins, and capsule; (2) determine whether EVs act as a transport mechanism to deliver S. aureus virulence factors into host cells; and (3) investigate EV-induced inflammasome activation and its biological role in S. aureus infections. To accomplish these goals, a multidisciplinary approach will be taken that combines genetics, molecular biology, cell biology, immunology, electron microscopy, biochemistry, and animal infection models. These efforts are essential for gaining a functional appreciation of the role that S. aureus EVs play in the host-pathogen interaction. The knowledge obtained from this study will deepen our currently limited understanding of microbial EVs and have broad implications for our understanding of the pathogenesis of Gram-positive pathogens.

项目摘要/摘要 金黄色葡萄球菌是一种重要的细菌病原体，会引起潜水员的人类疾病范围， 从轻度的皮肤病变到侵入性和威胁生命的感染。特征的病毒特征 金黄色葡萄球菌包括表面粘合剂和糖聚合物，以及分泌的蛋白质，例如细胞溶蛋白， 超抗原和蛋白酶，其中许多在免疫驱虫中起着至关重要的作用。金黄色葡萄球菌还产生纳米 大小，球形，双层，细胞外膜蔬菜（EV），具有不同的生物学活性。生产 电动汽车的代表哺乳动物细胞，真菌和细菌常见的秘密途径，可以无细胞 细胞间通信，但是革兰氏阳性细菌中EV生物发生的机制差 理解。金黄色葡萄球菌EV封装了包括表面粘合剂，脂蛋白，囊 多糖和脱蛋白，包括蛋白酶和形成孔的毒素，这些毒素已显示出来 在细菌病毒和生物信号传播到宿主细胞中的作用。该项目的总体目标 是为了更好地理解金黄色葡萄球菌在 葡萄球菌感染。该项目假设是EV通过用作一个 金黄色葡萄球菌用于运输毒素，细胞质蛋白和脂蛋白的新型秘书途径 进入宿主细胞，同时保护货物免受外部环境的检测或破坏。初步的 数据表明金黄色葡萄球菌EVS包一个病毒因子阵列，被巨噬细胞占用，并且是 各种宿主细胞的细胞毒性。此外，金黄色葡萄球菌EV会引起caspase-1的清洁和成熟的释放 人类巨噬细胞中的IL-1β和IL-18，以脂蛋白依赖性方式。这些结果突出了 炎性体激活中的电动汽车，这是一种重要的细胞内免疫病，已证明可以发挥 在确定金黄色葡萄球菌感染的结果中的关键作用。产生电动汽车的特定机制 EV从细菌细胞中释放的下游影响是该提案的目标。具体目的 该应用是：（1）阐明金黄色葡萄球菌中EV生物发生的机制和电动汽车的作用 在Sa细胞释放中，细胞质蛋白，脂蛋白和胶囊； （2）确定电动汽车是否充当 运输机制将金黄色链球菌病毒因子输送到宿主细胞中； （3）调查EV诱导的 炎性体激活及其在金黄色葡萄球菌感染中的生物学作用。为了实现这些目标， 将采用多学科方法，结合遗传学，分子生物学，细胞生物学，免疫学， 电子显微镜，生物化学和动物感染模型。这些努力对于获得 对金黄色葡萄球菌EV在宿主 - 病原体相互作用中所起的作用的功能欣赏。知识 从这项研究中获得的将加深我们当前对微生物电动汽车的了解，并具有广泛的了解 我们对革兰氏阳性病原体的发病机理的理解的意义。