Staphylococcal Superantigen Interactions With Vaginal Epithelium

葡萄球菌超抗原与阴道上皮的相互作用

• 批准号: 7728629
• 负责人: Marnie L Peterson
• 金额: $ 29.52万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-13 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7728629
• 关键词: Affect; Amino Acids; Area; Asthma; Atopic Dermatitis; Bacteria; Binding; Biological Models; Blood Circulation; Cells; Collaborations; Cytolysins; Cytotoxin; Data; Dermatitis; Development; Disease; Dose; Environment; Epithelial; Epithelial Cells; Epithelial Receptor Cell; Epithelium; Event; Exotoxins; Exposure to; Family suidae; Fever; Goals; Human; Immune system; Infection; Inflammation; Inflammatory; Intestines; Iowa; Knock-out; Knowledge; Lead; Life; Mediating; Microbe; Minnesota; Modeling; Mucous Membrane; Organism; Pathogenesis; Pathology; Penetration; Permeability; Pneumonia; Principal Investigator; Production; Property; Proteins; Receptor Cell; Reporting; Research; Research Personnel; Resources; Rhinitis; Role; Secondary to; Shock; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Skin; Soft Tissue Infections; Staphylococcus aureus; Streptococcal Infections; Structure; Submucosa; Superantigens; Surface; Syndrome; T-Cell Activation; T-Lymphocyte; Testing; Therapeutic; Thick; Tissues; Toxic Shock Syndrome; Toxic Shock Syndrome Toxin-1; Toxic effect; Toxin; United States; Vagina; Work; base; cytokine; cytotoxic; experience; human disease; improved; innovation; interest; macrophage; microbial; mutant; novel; novel strategies; novel therapeutics; perforin; prevent; programs; public health relevance; receptor; receptor binding; response; therapeutic development

DESCRIPTION (provided by applicant): The long-term goals of this research are to understand how Staphylococcus aureus and its superantigens (SAgs), cytotoxins, and other exoproteins interact with mucosal surfaces to facilitate SAg penetration to cause serious human illnesses. We propose to use the vaginal epithelium as the model multi-layered mucosal surface, and hypothesize the data obtained in planned studies will also be applicable to other mucosal surfaces. Prior results using an ex vivo porcine vaginal permeability model indicate that the SAg, TSST-1, traverses mucosal surfaces in small amounts, but localizes in higher amounts within the inner epithelium, possibly serving as a toxin reservoir. In the presence of staphylococcal 1-toxin, TSST-1 penetrated the full thickness of the vaginal mucosa in significantly higher amounts, with considerable TSST- 1 also remaining within the epithelium. We hypothesize that cytotoxic and inflammatory properties of staphylococcal cytotoxins and other exoproteins enhance penetration of TSST-1 to inner epithelial cells where TSST-1 binds to an undescribed epithelial cell receptor, triggering pro-inflammatory cytokine production. Base on these hypotheses we propose two specific aims: 1) To determine the contribution of S. aureus cytotoxins (exoproteins) in enhancing the penetration of TSST-1 across epithelial surfaces by causing cytolytic and/or inflammatory effects on epithelial cells, and 2) To determine TSST-1 receptor binding and the mechanism of TSST-1 stimulation of epithelial cells, leading to intracellular activation of signaling pathways with subsequent cytokine production. Our preliminary data suggest that the most likely candidate exoproteins to facilitate penetration of TSST-1 across mucosal barriers are cytotoxins, including 3-toxin, which we propose to study in depth through use of purified 3-toxin components and allelic replacement knockout strains. In the course of these studies, we will also study mucosal penetration and activities of a deletion [missing amino acids 1 to 72] mutant TSST-1 protein (13,000 MW vs. 22,000 MW wild-type TSST-1) that maintains superantigenicity and is associated with a rapidly progressive, 100% fatal, extreme pyrexia syndrome in humans. We believe the planned studies will clarify the mechanisms by which TSST-1 penetrates mucosal barriers to cause large numbers of human diseases. These studies may suggest novel therapeutic strategies to manage serious S. aureus illnesses. PUBLIC HEALTH RELEVANCE: The bacterium Staphylococcus aureus often initiates serious human diseases from the organism's colonization of mucous membranes, followed by secretion of potent exotoxins referred to as superantigens. Illnesses include toxic shock syndrome that may have both menstrual and non- menstrual forms, and that may affect thousands of humans each year in the United States. This application studies the mechanism by which superantigens penetrate mucosal surfaces, allowing S. aureus to cause life threatening toxic shock syndrome, and possibly suggesting novel strategies to prevent and manage such illnesses.

描述(申请人提供)：这项研究的长期目标是了解金黄色葡萄球菌及其超抗原(SAG)、细胞毒素和其他外源蛋白如何与粘膜表面相互作用，促进SAG穿透，从而导致严重的人类疾病。我们建议使用阴道上皮作为多层粘膜表面的模型，并假设在计划的研究中获得的数据也将适用于其他粘膜表面。先前使用体外猪阴道通透性模型的结果表明，SAG，TSST-1，少量穿越粘膜表面，但在内上皮内定位较高，可能作为毒物储存库。在葡萄球菌毒素存在的情况下，TSST-1以显著较高的量穿透整个阴道粘膜，相当数量的TSST-1也留在上皮内。我们假设葡萄球菌细胞毒素和其他外源蛋白的细胞毒性和炎症特性增强了TSST-1对内皮细胞的渗透，在那里TSST-1与一种未知的上皮细胞受体结合，触发促炎细胞因子的产生。基于这些假设，我们提出了两个特定的目标：1)确定金黄色葡萄球菌细胞毒素(外源蛋白)通过引起细胞溶解和/或炎症作用促进TSST-1穿过上皮细胞的作用；2)确定TSST-1受体结合和TSST-1刺激上皮细胞的机制，导致细胞内信号通路的激活和随后的细胞因子产生。我们的初步数据表明，最有可能促进TSST-1穿透粘膜屏障的候选外源蛋白是细胞毒素，包括3-毒素，我们建议通过使用纯化的3-毒素成分和等位基因替换敲除菌株对其进行深入研究。在这些研究过程中，我们还将研究缺失[缺失氨基酸1至72]突变TSST-1蛋白(13,000 mW对22,000 mW野生型TSST-1)的粘膜穿透性和活性，该蛋白保持超抗原性，并与人类快速进展的100%致命的极端发热综合征有关。我们相信，计划中的研究将澄清TSST-1穿透粘膜屏障导致大量人类疾病的机制。这些研究可能会提出新的治疗策略来管理严重的金黄色葡萄球菌疾病。与公共卫生相关：金黄色葡萄球菌通常会引起严重的人类疾病，原因是该菌在粘膜上的定植，随后会分泌出被称为超抗原的强效外毒素。疾病包括中毒性休克综合征，它可能有经期和非经期两种形式，在美国每年可能会影响数千人。这项应用研究了超抗原穿透粘膜表面的机制，使金黄色葡萄球菌能够引起危及生命的中毒性休克综合征，并可能提出预防和管理此类疾病的新策略。