C1 INHIBITOR-MEDIATED PROTECTION FROM ENDOTOXIN SHOCK

C1 抑制剂介导的内毒素休克保护

• 批准号: 6917375
• 负责人: ALVIN E DAVIS
• 金额: $ 47.25万
• 依托单位: IMMUNE DISEASE INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6917375
• 关键词: binding sites; complement inhibitors; complement pathway regulation; cytoskeleton; endotoxins; enzyme linked immunosorbent assay; gram negative bacteria; immunopharmacology; immunosuppression; intermolecular interaction; laboratory mouse; leukocyte activation /transformation; lipopolysaccharides; macrophage; microorganism disease chemotherapy; nonhuman therapy evaluation; pharmacokinetics; protein binding; protein structure function; recombinant proteins; septicemia; shock; surface plasmon resonance; vascular endothelium; vascular endothelium permeability

DESCRIPTION (provided by applicant): Infusion of C1 inhibitor (C1INH) protects mice, dogs, rabbits and baboons from gram negative bacterial sepsis and shock. Protection has been assumed to result from inhibition of activation of the complement and/or contact systems. Because C1INH is so effective, we hypothesized that it might bind to LPS, and that this interaction might interfere with the ability of LPS to activate macrophages. Preliminary studies support this hypothesis. Specific Aim 1 will analyze the C1INH-LPS interaction. The binding site will be defined using recombinant mutated C1INH proteins, which will be analyzed for the ability to bind to LPS (ELISA and surface plasmon resonance), to inhibit binding of LPS to, and activation of, macrophages. The ability of C1 INH to protect mice from endotoxin shock will be directly compared with that of other endotoxin antagonists. Specific Aim 2 will define the role of C1INH in protection from LPS-induced endothelial injury. To analyze the effect of C1INH on LPS-induced vascular permeability, endothelial cell cytoskeletal alterations and cell barrier dysfunction will be characterized, as will the ability of C1INH, C1INH mutants and the amino terminal domain to reverse LPS-mediated increased vascular permeability. Specific Aim 3 will characterize the clearance and organ localization of C1INH-LPS complexes in mice. In addition, the internalization and degradation of C1INH-LPS complexes by different cell types will be analyzed in vitro. The effect of C1INH on LPS tolerance in mice (induced by low doses of LPS) will be determined. Lastly, because sepsis models are more biologically relevant to human disease and because some agents that are protective in endotoxin shock models may not be protective (or may even be harmful) in sepsis, Specific Aim 4 will analyze the role of C1INH and C1 INH variants in protection in the cecal ligation/puncture model in mice. These studies will lead to improved understanding of the role played by C1INH in the cbrresistance to gram negative sepsis and endotoxin shock, and may lead to new therapies for these diseases.

描述（由申请人提供）： 输注C1抑制剂（C1 INH）可保护小鼠、犬、兔和狒狒免受革兰氏阴性细菌败血症和休克。保护作用被认为是由于抑制补体和/或接触系统的激活。由于C1 INH是如此有效，我们假设它可能与LPS结合，并且这种相互作用可能干扰LPS激活巨噬细胞的能力。初步研究支持这一假设。具体目标1将分析C1 INH-LPS相互作用。将使用重组突变的C1 INH蛋白来定义结合位点，将分析其结合LPS的能力（ELISA和表面等离子体共振），以抑制LPS与巨噬细胞的结合和巨噬细胞的活化。C1 INH保护小鼠免受内毒素休克的能力将直接与其他内毒素拮抗剂的能力进行比较。具体目标2将定义C1 INH在保护免受LPS诱导的内皮损伤中的作用。为了分析C1 INH对LPS诱导的血管通透性的影响，将表征内皮细胞细胞骨架改变和细胞屏障功能障碍，C1 INH、C1 INH突变体和氨基末端结构域逆转LPS介导的血管通透性增加的能力也将如此。具体目标3将表征小鼠中C1 INH-LPS复合物的清除和器官定位。此外，将在体外分析不同细胞类型对C1 INH-LPS复合物的内化和降解。将确定C1 INH对小鼠中LPS耐受性（由低剂量LPS诱导）的影响。最后，由于脓毒症模型与人类疾病在生物学上更相关，并且由于在内毒素休克模型中具有保护性的一些药剂在脓毒症中可能不具有保护性（或甚至可能是有害的），因此具体目标4将分析C1 INH和C1 INH变体在小鼠盲肠结扎/穿刺模型中的保护作用。这些研究将导致更好地理解C1 INH在抵抗革兰氏阴性脓毒症和内毒素休克中所起的作用，并可能导致这些疾病的新疗法。