High-throughput Screenings to Identify Host Receptors for Staphylococcal Adhesins

高通量筛选鉴定葡萄球菌粘附素宿主受体

• 批准号: 8030791
• 负责人: RENATA PASQUALINI
• 金额: $ 8.43万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8030791
• 关键词: Adherence; Adhesions; Adhesives; Affect; Alternative Therapies; American; Animal Model; Antibiotic Resistance; Bacteria; Bacterial Adhesins; Binding; Biology; Blood Circulation; Cell Surface Proteins; Cell Wall; Communicable Diseases; Communities; Comorbidity; Cost-Benefit Analysis; Data; Disease; Endocarditis; Environment; Epidemic; Event; Family; Feasibility Studies; Genus staphylococcus; Gram-Positive Bacteria; Healthcare Systems; Hospitals; Immunocompromised Host; Immunomodulators; Individual; Infection; Infectious Skin Diseases; Invaded; Lactococcus lactis; Ligands; Lower respiratory tract structure; Mediating; Medical; Methodology; Minor; Molecular; Organism; Pathogenesis; Pathology; Pattern; Phage Display; Play; Pneumonia; Process; Proteins; Recombinants; Research; Role; Screening procedure; Sepsis; Skin Tissue; Soft Tissue Infections; Staging; Staphylococcal Infections; Staphylococcus aureus; Staphylococcus epidermidis; Surface; System; Techniques; Technology; Tissues; Toxin; United States; Vaccination; Vaccines; Virulence Factors; Virulent; Work; base; design; disorder prevention; drug development; high throughput screening; microbial; mortality; mutant; novel; pathogenic bacteria; receptor; therapeutic target; vaccine development

DESCRIPTION (provided by applicant): Staphylococci cause a wide spectrum of infectious diseases spanning from rather minor skin infections to serious conditions such as sepsis, pneumonia and endocarditis. Although Staphylococcus aureus is by far the most virulent of species, Staphylococcus epidermidis and Staphylococcus lugdunensis have also been found to cause severe infections mostly in immunocompromised individuals. In the past, highly virulent S. aureus strains were confined to the hospital environment mostly affecting immunocompromised patients or individuals with underlying co-morbidities. Unfortunately, similar strains have recently emerged in the community causing severe infections in otherwise healthy individuals. To a lesser extent and slightly different pathology, Staphylococcus epidermidis and Staphylococcus lugdunensis seem to follow the same pattern. Most of these strains have evolved to be resistant to antibiotics, which resulted in a worldwide epidemic and an enormous burden for the healthcare system. Therefore, the necessity of a vaccine or identification of novel or alternative therapies for the treatment of these infections has become an unmet and pressing medical need. Despite intense efforts, the molecular mechanism of staphylococcal infections is incompletely understood, but it seemingly involves a large number of virulence factors such as adhesins, toxins and immunomodulators. To date, adhesion to host tissues is considered the foremost stage of infection and plays a vital role in the survival of the invading organism. Most likely, the synthesis of toxins and immunomodulators plays a role later in the disease process and depends on the first step of infection. Hence, proteins responsible for adherence have long been recognized as targets for drug and vaccine development. In staphylococci, as well as other Gram-positive bacteria, adhesion to host tissues is mostly mediated by a family of cell-wall-anchored (CWA) proteins referred to us microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). These proteins have been shown to a) mediate adherence to host proteins, b) participate in self-aggregation and c) modulate the biology of the ligand protein. Furthermore, MSCRAMMs have been shown to be virulence factors in animal models of infection since a mutant lacking all these molecules fails to cause disease. Vaccination with recombinant MSCRAMMs or inhibition of their functions resulted in significant protection against disease. Based on these observations, it is widely agreed that identification of ligands for MSCRAMMs would contribute to a better understanding of molecular events leading to infection and would help us design effective vaccine or targeted therapeutics for disease prevention and treatment. To that end, this proposed research aims to establish a high-throughput phage display methodology to identify ligands for MSCRAMMs. This work will also serve as a feasibility study to determine if this technique is suitable for large-scale ligand discovery for bacterial cell surface proteins. PUBLIC HEALTH RELEVANCE: Staphylococcus aureus is the leading cause of bloodstream, lower respiratory tract, skin and soft tissue infections in the United States with an annual mortality approaching 100,000 Americans lives. Our research aims to better understand staphylococcal infection and to set the grounds for targeted therapies against this disease.

描述（由申请人提供）：葡萄球菌引起各种各样的传染病，这些传染病从相当小的皮肤感染到严重的疾病，例如败血症，肺炎和心内膜炎。尽管金黄色葡萄球菌是迄今为止最有毒的物种，但也发现表皮葡萄球菌和lugdunensis葡萄球菌主要引起严重的感染，主要是在免疫功能低下的个体中引起的。过去，高毒的金黄色葡萄球菌菌株仅限于医院环境，主要影响免疫功能低下的患者或具有潜在的合并症的人。不幸的是，最近在社区中出现了类似的菌株，引起了其他健康的个体的严重感染。在较小程度上，病理学略有不同，表皮葡萄球菌和lugdunensis葡萄球菌似乎遵循相同的模式。这些菌株中的大多数已经进化为对抗生素的抵抗力，这导致了全球流行病和医疗保健系统的巨大负担。因此，需要进行疫苗或对这些感染治疗的新型或替代疗法的鉴定已成为一种未满足和紧迫的医疗需求。 尽管做出了巨大的努力，但葡萄球菌感染的分子机制仍未完全理解，但似乎涉及大量的毒力因子，例如粘附素，毒素和免疫调节剂。迄今为止，对宿主组织的粘附被认为是感染的最重要阶段，并且在入侵生物的存活中起着至关重要的作用。毒素和免疫调节剂的合成最有可能在疾病过程中起作用，并取决于感染的第一步。因此，长期以来，负责依从性的蛋白质已被认为是药物和疫苗开发的靶标。 在葡萄球菌以及其他革兰氏阳性细菌中，对宿主组织的粘附主要是由识别美国微生物表面成分的一组细胞壁锚定（CWA）蛋白介导的，这些蛋白识别识别粘合剂基质分子（MSCRAMMS）。这些蛋白已显示为a）介导对宿主蛋白的依从性，b）参与自聚集，c）调节配体蛋白的生物学。此外，由于缺乏所有这些分子的突变体未能引起疾病，因此已显示MSCramms是动物感染模型中的毒力因子。重组MSCRAMMS的疫苗接种或对其功能的抑制导致对疾病的明显保护。基于这些观察结果，人们普遍认为，MSCramms配体的鉴定将有助于更好地理解导致感染的分子事件，并有助于我们设计有效的疫苗或针对性的预防疾病预防和治疗。 为此，这项拟议的研究旨在建立高通量噬菌体显示方法，以识别MSCramms的配体。这项工作还将作为一项可行性研究，以确定该技术是否适用于细菌细胞表面蛋白的大规模配体发现。 公共卫生相关性：金黄色葡萄球菌是美国血液，下呼吸道，皮肤和软组织感染的主要原因，年死亡率接近100,000美国人的生活。我们的研究旨在更好地了解葡萄球菌感染，并为针对这种疾病的有针对性疗法树立理由。