MOLECULAR ANALYSIS OF ENDOTOXIN RECEPTOR FUNCTION

内毒素受体功能的分子分析

• 批准号: 6107528
• 负责人: Theo N Kirkland
• 金额: $ 15.89万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 1999-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6107528
• 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理解的重大飞跃 已发现细胞上和体内的 LPS 受体蛋白 等离子体。 CD14 是一种 55 kDa 糖磷脂酰肌醇连接蛋白 表面表达于巨噬细胞和多形核细胞表面 白细胞。它也在等离子体中循环。膜型和可溶性两种 CD14是人类LPS识别系统的关键部分。 巨噬细胞通过 CD14 刺激产生细胞因子、酶和 对 LPS 的各种其他反应。其他刺激性细菌产品， 例如来自革兰氏阳性菌的肽聚糖和脂蛋白， 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 LPS 复合，刺激内皮细胞，平滑肌细胞 肌肉细胞、星形胶质细胞和系膜细胞表达 ICAM、ELAM、E- 选择素，产生细胞因子和一氧化二氮。在过去的五年里， 我们已经描述了 N 端内的一些关键区域 CD14 的一半。 CD14 与其他 LPS 结合蛋白不同源。我们的 假设是确定 CD14 的具体结构特征 编码 CD14 的各种功能将产生新颖且 有关 LPS-蛋白质相互作用和随后的有意义的信息 细胞的活化。我们的目标是定义结构特征 CD14的组成决定了其功能。本次活动的具体目标 建议是： 1. 确定CD14的结构区域 使 CD14 能够结合脂多糖，与 LBP 相互作用，启动 表达 mCD14 的细胞的细胞激活，实现内化 LPS-LBP 复合物，通过 sCD14-LPS 依赖性激活细胞 途径； 2. 测试CD14的结构特征是否符合 识别 LPS 也参与识别表面分子 3. 革兰氏阳性微生物的三维度测定 通过多维NMR和X射线晶体学我们鉴定了CD14的结构 相信更好地理解 CD14 的结构域可能 允许设计新的治疗策略来治疗脓毒症 震惊。由于感染性休克目前的死亡率为 50%，并且 住院患者中常见的情况，有效的治疗 成为一项重大的医学进步。