Amelioration of Sepsis by Macrophage Activation

描述（由申请人提供）：危重患者经常出现复杂的疾病谱系，可能包括急性呼吸窘迫综合征，全身炎症反应综合征，感染性休克和多器官功能障碍综合征。导致感染性休克发生的机制尚不完全清楚。因此，死亡率仍然高得令人无法接受，即28.6%。巨噬细胞a类清除率受体（SRA）因其在巨噬细胞中摄取改性低密度脂蛋白、胆固醇酯积累及其在动脉粥样硬化中的作用而闻名。然而，最近的证据已经证明SRA作为一种先天免疫受体的作用。我们发现SRA在感染性休克的发病机制中也起着核心作用。具体来说，SRA增加了脓毒性休克的发病率和死亡率。这是SRA在脓毒性疾病发病机制中的新发现。SRA介导感染性休克的机制涉及与感染性休克相关的促炎、促死亡表型的扩增。此外，SRA通过组构性抑制TRIF/IRF /IFN？促生存信号通路。除了这些重要的基础科学观察外，我们的研究还提出了治疗和管理感染性休克的新方法。我们假设：i) SRA通过放大与脓毒性休克相关的促炎、促死亡表型，在脓毒性休克的病理生理中起关键作用；ii) SRA是TRIF/IRF /IFN？促生存信号通路和iii) SRA活性的调节和/或外源性IFN的管理？将有助于管理和预防败血症/感染性休克。我们将以以下具体目标批判性地评估这些假设。描述SRA增强脓毒症/感染性休克的促炎反应的机制。2. 定义SRA抑制TRIF/IRF /IFN的机制信号通路。3. 确定SRA和/或外源性IFN是否有短暂的拮抗作用？将改善脓毒性休克的后遗症和提高生存结果。这项研究的成功完成将导致对脓毒症的细胞和分子机制的新认识，也可能为预防和治疗脓毒症/感染性休克找到新的方法。

DESCRIPTION (provided by applicant): The critically ill patient frequently develops a complex disease spectrum that may include acute respiratory distress syndrome, systemic inflammatory response syndrome, septic shock and multiple organ dysfunction syndrome. The mechanisms that lead to the development of septic shock are not fully understood. For this reason the mortality rate remains unacceptably high, i.e. 28.6%. The macrophage class a scavenger receptor (SRA) is best known for its role in the uptake of modified low density lipoprotein, accumulation of cholesteryl esters in macrophages and its role in atherogenesis. However, recent evidence has demonstrated a role for SRA as an innate immune receptor. We have discovered that SRA also plays a central role in the pathogenesis of septic shock. Specifically, SRA enhances the morbidity and mortality of septic shock. This is a new and novel role for SRA in the pathogenesis of septic disease. The mechanisms by which SRA mediates septic shock involves amplification of the pro-inflammatory, pro-death phenotype associated with septic shock. In addition, SRA facilitates septic sequelae by constitutively inhibiting the TRIF/IRF?/IFN? pro-survival signaling pathway. In addition to these important basic science observations, our studies have also suggested new and novel approaches for the treatment and management of septic shock. We hypothesize that: i) SRA plays a pivotal role in the pathophysiology of septic shock by amplifying the pro-inflammatory, pro-death phenotype associated with septic shock; ii) SRA is an endogenous inhibitor of the TRIF/IRF?/IFN? pro- survival signaling pathway and iii) Modulation of SRA activity and/or administration of exogenous IFN? will be useful in the management and prevention of sepsis/septic shock. We will critically evaluate these hypotheses with the following specific Aims. 1. Delineate the mechanisms by which SRA enhances the pro-inflammatory response to sepsis/septic shock. 2. Define the mechanisms by which SRA inhibits the TRIF/IRF?/IFN? signaling pathway. 3. Determine whether transient antagonism of SRA and/or administration of exogenous IFN? will ameliorate septic sequelae and improve survival outcome in septic shock. A successful completion of this research will result in a new understanding of the cellular and molecular mechanisms of sepsis and may also identify new and novel approaches for the prevention and treatment of sepsis/septic shock.