PROJECT 2 - Mechanisms of Hypervirulence in the Pathogenesis of Sepsis

项目摘要 这些目标解决了整个计划的中心假设：蛋白质糖基化和糖蛋白 重塑改变了脓毒症的凝血障碍和炎症。提出的研究是基于新兴的 败血症的特征，免疫系统强加的自然选择会导致 超强毒力变异株具有更高的侵袭性疾病风险。超强毒力被认为是由一种 病原体特定的决定因素和宿主反应的组合。在上一个赠款周期中，我们有 证明宿主对实验性脓毒症的反应是通过多种机制发生的，包括改变 在血液糖蛋白重塑方面。拟议的研究重点是超强毒力细菌和宿主的作用 糖蛋白重塑反应导致凝血功能异常的加速发生和进展 脓毒症的炎症。该项目利用了项目负责人和核心人员的综合专业知识 脓毒症的病理生理学，包括凝血、炎症、蛋白质组学和糖生物学 并使用该计划的所有核心设施。项目负责人发现了超强毒力的沙门氏菌 霍乱(SC)临床分离株，是自然界中发现的最致命的沙门氏菌之一。SC通常 引起人类败血症或肠外感染，但与常见的食物中毒密切相关 病原体为鼠伤寒沙门氏菌(ST)。我们已经证明，在实验性的ST和E.Coli败血症中， 病原体选择性宿主导致血液中抗炎碱性磷酸酶(AP)的水平 反应-神经氨酸酶活性(Neu)的诱导和由此产生的AP分析，并通过 Ashwell-Morell受体(AMR)。AP减少可减少内毒素的解毒，从而增加炎症 和死亡率。相反，我们最近的发现表明，SC不能诱导Neu活动，也不能清除AP， 但AMR缺乏症仍然具有保护性，这意味着其他宿主糖蛋白的参与，以及它们的 鉴定可能揭示调控超强毒力和脓毒症的新途径和新机制。其他内容 初步数据显示，SC由于宿主水平降低而导致促炎状态增加 诱导IL-10，一种免疫调节细胞因子，影响败血症疾病的预后。此外，分层 由革兰氏阴性病原体引起的实验性和人类败血症可能包括病原体选择性 循环中凝血因子XI活性的调节。拟议的研究将确定和调查环境， 决定超强毒力的遗传和蛋白质组学机制，包括AMR、IL-10和凝血 因子XI，以及它们在实验性和人类败血症分层和预后中的作用。这个 首要目标是确定病原体和宿主决定的成分和机制。 毒力和败血症发病机制，导致诊断生物标志物的发现和合理设计 几十年来一直未被发现的治疗剂。

Project Summary The aims address the central hypothesis of the overall program: Protein glycosylation and glycoprotein remodeling alter the coagulopathy and inflammation of sepsis. Proposed research is based on the emerging hallmark of sepsis whereby natural selection imposed by the immune system results in the generation of hypervirulent strain variants with increased risk of invasive disease. Hypervirulence is believed to arise from a combination of pathogen-specific determinants and host responses. Over the last grant cycle, we have demonstrated that host responses to experimental sepsis occur by multiple mechanisms including alterations in blood glycoprotein remodeling. Proposed research focuses on the role of hypervirulent bacteria and host glycoprotein remodeling responses leading to accelerated onset and progression of coagulation abnormalities and inflammation of sepsis. This project utilizes the combined expertise of the Project Leaders and Core Directors in the pathophysiology of sepsis, including coagulation, inflammation, proteomics and glycobiology and engages all of the core facilities of the program. The Project Leader discovered hypervirulent Salmonella Choleraesuis (SC) clinical isolates that are among the most virulent Salmonella found in nature. SC typically causes sepsis or extra-intestinal infections in humans yet is closely related to the common food-poisoning pathogen Salmonella Typhimurium (ST). We have shown that in experimental ST and E. coli sepsis, reduced blood levels of anti-inflammatory alkaline phosphatase (AP) enzymes result from pathogen-selective host responses – induction of neuraminidase activities (Neu) and resultant AP desialylation, and clearance by the Ashwell-Morell receptor (AMR). AP reductions diminish LPS de-toxification thereby increasing inflammation and mortality. In contrast, our recent findings indicate that SC does not induce Neu activities nor AP clearance, but AMR deficiency remains protective, implicating the involvement of other host glycoproteins, and their identification may reveal new pathways and mechanisms modulating hypervirulence and sepsis. Additional preliminary data suggest that SC elicits an increased pro-inflammatory state due to diminished levels of host induction of IL-10, an immune modulatory cytokine that affects sepsis disease outcome. Further, stratification of experimental and human sepsis caused by Gram-negative pathogens may include pathogen-selective modulation of Factor XI activity in circulation. Proposed research will identify and investigate environmental, genetic, and proteomic mechanisms determining hypervirulence including the AMR, IL-10, and coagulation Factor XI, and their utility in the stratification and prognosis of experimental and human sepsis. The overarching goal is to identify components and mechanisms of both the pathogen and host determining virulence and sepsis pathogenesis, leading to diagnostic biomarker discovery and rational design of therapeutic agents that have eluded discovery for decades.