Activation of human TLR4 by endotoxin binding to MD-2

描述（由申请人提供）：这项为期五年的提案旨在促进免疫学和传染病领域学术临床医生研究人员的职业生涯。 候选人将完成传染病方面的进修培训，并被任命为埃默里大学医学院医学系传染病科教师。 她的职业发展将得到杰出医学教授、微生物学和免疫学、流行病学教授、传染病科主任 David S. Stephens 博士的指导。 该研究计划将在斯蒂芬斯博士的实验室进行，该实验室在微生物发病机制和分子遗传学方面拥有长期而成功的记录。 Toll 样受体 4 (TLR4) 及其辅助蛋白 MD-2 和内毒素负责引发脑膜炎球菌和其他革兰氏阴性菌引起的败血症的大部分炎症反应。实验室之前的工作已经确定了脑膜炎球菌 KDO2-脂质 A 在 TLR4/MD-2 受体复合物激活中的重要作用。 假设 MD-2 是 TLR4 激活的特定决定因素，并且 KDOz-脂质 A 内毒素结构对于直接结合 MD-2 至关重要。 将研究 KDO 在与 MD-2 结合中的重要性、与 MD-2 结合的其他内毒素结构要求以及 TLR4 的激活。 具体目标 1：使用遗传和生物化学定义的脑膜炎球菌脂寡糖确定与人衔接蛋白 MD-2 相互作用所需的脑膜炎球菌 KDO2-脂质 A 结构。 具体目标 2：确定通过辅助蛋白 MD-2 胞外激活 TLR4 所需的一般内毒素结构。 意义。 了解 MD-2 在内毒素激活 TLR4 中的作用可能会影响改变炎症免疫反应的治疗干预措施。该提案将鉴定最能被 MD-2 有效识别并呈递给 TLR4 的细菌内毒素成分。 对由 TLR4 和 MD-2 激活介导的炎症成分的其他疾病（例如动脉粥样硬化、炎症性肠病和哮喘）的研究也可能受益于这项工作。

DESCRIPTION (provided by applicant): This five-year proposal is designed to promote a career as an academic clinician investigator in the fields of immunology and infectious diseases. The candidate will complete fellowship training in infectious diseases and be appointed to the faculty of the Emory University School of Medicine, Department of Medicine, Division of Infectious Diseases. Her career development will be mentored by Dr. David S. Stephens, Distinguished Professor of Medicine, and Professor of Microbiology and Immunology, and Epidemiology, and Director Division of Infectious Diseases. This research plan will be conducted in Dr. Stephens' laboratory which has a long and successful track record in microbial pathogenesis and molecular genetics. The Toll-like receptor 4 (TLR4), together with its accessory protein MD-2, and endotoxin are responsible for initiating much of the inflammatory response in sepsis caused by meningococci and other gram-negative bacteria. Previous work in the laboratory has identified an important role for meningococcal KDO2-lipid A in activation of the TLR4/MD-2 receptor complex. The hypothesis is that MD-2 is a specific determinant of TLR4 activation and that the KDOz-lipid A endotoxin structure is critically important for direct binding to MD-2. The importance of KDO in binding to MD-2, other endotoxin structural requirements for binding to MD-2 and the activation of TLR4 will be investigated. Specific Aim 1: Determine the meningococcal KDO2-lipid A structure required for interaction with the human adaptor protein MD-2 using genetically and biochemically defined meningococcal lipooligosaccharides. Specific Aim 2: Determine the general endotoxin structure required for extracellular activation of TLR4 via the accessory protein MD-2. Significance. Understanding the role of MD-2 in TLR4 activation by endotoxin may impact therapeutic interventions that modify the inflammatory immune response. This proposal will identify the components of bacterial endotoxin which are most efficiently recognized by MD-2 and presented to TLR4. The study of other diseases (e.g. atherosclerosis, inflammatory bowel disease, and asthma) with inflammatory components which are mediated by the activation of TLR4 and MD-2 may also benefit from this work.