MOLECULAR ANALYSIS OF ENDOTOXIN RECEPTOR FUNCTION

内毒素受体功能的分子分析

• 批准号: 6413617
• 负责人: Theo N Kirkland
• 金额: $ 24.29万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6413617
• 关键词: Baculoviridae; CD antigens; X ray crystallography; carbohydrate receptor; cellular pathology; endotoxins; lipopolysaccharides; molecular pathology; nuclear magnetic resonance spectroscopy; protein structure function; receptor binding; septic shock; surface antigens; tissue /cell culture

Septic shock is a highly lethal syndrome triggered by bacterial toxins. A major leap in our understanding of the pathogenesis of septic shock has been the discovery of LPS receptor protein on cells and in the plasma. CD14 is a 55 kDa glycophosphatidylinositol-linked protein surface expressed on the surface of macrophages and polymorphonuclear leucocytes. It also circulates in the plasma. Both membrane and soluble CD14 are critical parts of the LPS recognition system in human beings. Macrophages are stimulated via CD14 to make cytokines, enzymes and a variety of other responses to LPS. Other stimulatory bacterial products, such as peptidoglycan and lipoprotein from Gram-positive bacteria and lipoarabinomannan from mycobacteria also stimulate responses via CD14. Soluble CD14 complexed with LPS stimulates endothelial cells, smooth muscle cells, astrocytes and mesangial cells to express ICAM, ELAM, E- selectin, to make cytokines and nitrous oxide. Over the past five years, we have described some of the critical regions within the N-terminal half of CD14. CD14 is not homologous to other LPS binding proteins. Our hypothesis is that determining the specific structural features of CD14 which encode the various functions of CD14 will yield novel and meaningful information about LPS-protein interactions and the ensuing activation of cells. It is our goal to define the structural features of CD14 which determine its functions. The specific aims of this proposal are: 1. To determine the structural regions of CD14 which enable CD14 to bind lipopolysaccharides, interact with LBP, initiate cellular activation of cells expressing mCD14, enable internalization of LPS-LBP complexes, activate cells via the sCD14-LPS-dependent pathway; 2. To test whether the structural features of CD14 which recognize LPS are also involved in recognizing the surface molecules of Gram-positive microorganisms 3. To determine the three dimensional structure of CD14 by multidimensional NMR and X-ray crystallography we believe that better understanding of the structural domains of CD14 may allow design of new therapeutic strategies for the treatment of septic shock. Since septic shock currently has a mortality rate of 50%, and is a common occurrence in hospitalized patients, effective therapy would be a major medical advance.

感染性休克是一种由细菌毒素引发的高度致命的综合征。 我们对感染性休克发病机制认识上的重大飞跃 已经发现了细胞上的内毒素受体蛋白和在 血浆。CD14是一种55 kDa的糖磷脂肌醇连接蛋白 巨噬细胞和中性粒细胞表面表达 白细胞。它也在血浆中循环。既有膜的又有可溶性的 CD14是人类内毒素识别系统的重要组成部分。 巨噬细胞通过CD14刺激产生细胞因子、酶和 对内毒素的其他反应的多样性。其他刺激性细菌产品， 例如来自革兰氏阳性细菌和 来自分枝杆菌的脂阿拉伯甘露聚糖也通过CD14刺激反应。 可溶性CD14与内毒素复合刺激内皮细胞，平滑 肌细胞、星形胶质细胞和系膜细胞表达ICAM、ELAM、E- 选择素，用来制造细胞因子和一氧化二氮。五年来， 我们已经描述了N-末端内的一些关键区域 CD14的一半。CD14与其他内毒素结合蛋白不具有同源性。我们的 假说是确定CD14的特定结构特征 其中编码CD14的各种功能将产生新的和 关于内毒素-蛋白质相互作用及其后续的有意义信息 激活细胞。我们的目标是定义结构特征 决定其功能的CD14。这样做的具体目的是 建议如下：1.确定CD14的结构区域 使CD14结合内毒素，与LBP相互作用，启动 表达mCD14的细胞的细胞激活，使其内化 在内毒素-LBP复合体中，通过依赖于sCD14-内毒素激活细胞 2.检测CD14的结构特征 识别脂多糖也参与识别表面分子 革兰氏阳性微生物3.测定三维 用多维核磁共振和X射线结晶学研究CD14的结构 相信更好地理解CD14的结构域可能会 允许设计治疗败血症的新治疗策略 令人震惊。由于感染性休克目前的死亡率为50%，而且 住院患者中常见的情况是，有效的治疗将 是医学上的一大进步。