AMELIORATION OF SEPSIS BY MACROPHAGE ACTIVATION

败血症综合征和感染性休克是发病率和死亡率的重要原因 危重病人的死亡率。尽管有技术和 重症监护的治疗进展，脓毒症仍然是关键 外科重症监护病房40%至60%的死亡人数。脓毒症 综合征每年发生在50万患者中，在最常见的患者中排名第13 美国的死因，估计造成10万人死亡 每年的死亡人数。不幸的是，败血症综合征的发病率出现了 在全国范围内不断增加。很明显，替代方法是 必须找到预防和/或处理败血症的办法。近期临床 研究表明(1-&gt；3)-β-D-葡聚糖激活巨噬细胞 将显著降低外科手术中败血症的发病率和死亡率 病人。我们的初步研究表明，它的防腐效果 葡聚糖可以通过改变较高的结构(即分支)来增强 聚合频率和聚合度)。这项研究 本提案中概述的将解决两个关键问题。我。在吗？ (1-&gt；3)-β-D-葡聚糖的分子构象 抗败血症效果如何？II.细胞和分子机制是什么 与葡聚糖诱导的脓毒症保护作用有关？我们将聘用 小鼠盲肠结扎穿孔(CLP)败血症模型的建立 感染性休克。鉴定(1&gt；3)-β-D-葡聚糖聚合物 显著的抗菌活性，我们将进行结构/活动 关系研究，以确定是否改变分子 构象、侧链支化频率和/或聚合物尺寸 增强小鼠CLP模型的抗败血症作用。当(1->3)- 发挥最佳抗败血症活性的β-D-葡聚糖已被 确定后，我们将开发聚合物的分子模型。我们会 研究(1-&gt；3)-β-D-葡聚糖的细胞和分子机制 通过确定：i)葡聚糖与巨噬细胞的结合是否涉及 一种特异性受体与脓毒症对葡聚糖巨噬细胞受体的影响 结合；以及ii)葡聚糖和/或脓毒症对巨噬细胞信号的影响 转导通路。此外，我们还将比较和对比系统 巨噬细胞肿瘤坏死因子α、白介素1β、白介素6和一氧化氮水平 有无葡聚糖和败血症。我们还将比较和 造影剂巨噬细胞肿瘤坏死因子α、白介素1β、白介素6、白介素8和诱导型一氧化氮 一氧化氮合酶基因的转录、翻译和精加工 有无葡聚糖和败血症。我们将特别强调 关于肿瘤坏死因子α的检测，因为葡聚糖可能抑制肿瘤的发展 通过下调巨噬细胞释放肿瘤坏死因子α而引发败血症后遗症。长的- 本研究的范围目标是了解S的发病机制。 葡聚糖可改善败血症和感染性休克。这些数据最终可能会导致 为病人制定更好的管理策略 易患败血症和感染性休克。

Sepsis syndrome and septic shock are significant causes of morbidity and mortality in critically ill patients. Despite technological and therapeutic advances in critical care, sepsis continues to be a pivotal factor in 40% to 60% of deaths in surgical intensive care units. Sepsis syndrome occurs in 500,000 patients per year and is the 13th most common cause of death in the United States, resulting in an estimated 100,000 deaths per year. Unfortunately, the incidence of sepsis syndrome appears to be increasing nationwide. It is clear that alternative approaches to the prevention and/or management of sepsis must be found. Recent clinical studies indicate that macrophage activation with (1->3)-beta-D-glucans will significantly reduce septic morbidity and mortality in surgical patients. Our preliminary studies indicate that the antisepsis efficacy of glucans can be enhanced by altering the higher structure (i.e. branching frequency and degree of polymerization) of the molecule. The research outlined in this proposal will address two critical questions. I. Is there a molecular conformation of(1->3)-beta-D-glucan that will exert optimal anti-sepsis efficacy? II. What are the cellular and molecular mechanisms associated with glucan induced protection against sepsis? We will employ the murine cecal-ligation and puncture (CLP) model of septicemia and septic shock. To identify the (1->3)-beta-D-glucan polymer with the most significant anti-sepsis activity, we will conduct structure/activity relationship studies to determine whether altering the molecular conformation, side-chain branching frequency and/or polymer size will enhance anti-sepsis efficacy in the murine CLP model. When the (1->3)- beta-D-glucan that exerts optimal anti-sepsis activity has been identified, we will develop a molecular model of the polymer. We will examine the cellular and molecular mechanisms of (1->3)-beta-D-glucan in sepsis by determining; i) whether glucan binding to macrophages involves a specific receptor and the effect of sepsis on glucan-macrophage receptor binding; and ii) the effect of glucan and/or sepsis on macrophage signal transduction pathways. In addition, we will compare and contrast systemic and macrophage TNFalpha, IL-1beta, IL-6 and nitric oxide levels in the presence and absence of glucan and sepsis. We will also compare and contrast macrophage TNFalpha, IL-1beta, IL-6, IL-8 and inducible nitric oxide synthase gene transcription, translation and elaboration in the presence and absence of glucan and sepsis. Special emphasis will be placed on examination of TNFalpha, since glucans may inhibit the development of septic sequelae by down-regulating macrophage TNFalpha release. The long- range goal of this research is to understand the mechanism(s) by which glucans ameliorate sepsis and septic shock. These data may ultimately lead to the development of better management strategies for patients predisposed to sepsis and septic shock.