Targeting TLR Signaling Pathways to Blunt Pathogen-mediated Acute Lung Injury

几十年来，“一种细菌，一种药物”的方法已经成为疫苗或治疗方法的特征。 特殊传染病。我们提出了一种不同的方法，基于新的治疗方法的发展， 通过利用流感和其他优先病原体感染期间触发的共同宿主先天免疫应答来预防传染病。流感病毒每年在全世界感染多达500万人， 杀死了大约50万人我们强有力的实验证据表明，有效的TLR 4拮抗剂， Alkoran（Alkorai，Inc.），以及多种其他TLR 4拮抗剂，显著降低急性肺损伤和 (ALI)和死亡率。西洋参醇不仅能阻断流感病毒介导的宿主来源的“DAMP”释放， 巨噬细胞中DAMP介导的TLR 4信号传导通常导致“细胞因子风暴”。虽然我们已经 阐明了流感介导ALI和致死性的几种新机制， 西曲康疗法（例如，通过TLR 4发出信号的宿主来源的DAMPS的释放;导致肺水肿的紧密连接通透性增加; IL-1α/β在致死性中的作用），我们对整体先天性 控制流感诱导的ALI和抗病毒蛋白介导的保护作用的免疫信号通路仍然不完整，需要进一步研究以开发高效的宿主导向疗法。因此，我们认为， 具体目标1将侧重于识别先天免疫机制，这两个流感敏感性和阿托伐他汀介导的保护。我们将利用转基因小鼠品系来解剖 信号通路被激活了无论TLR 4必须在基质细胞和/或髓样细胞上表达， 病毒诱导的上皮细胞坏死性凋亡在DAMP释放中的作用，非TLR 4 PRRs的作用机制 流感抗性/易感性，以及宿主需要TLR 2/TLR 4二聚化的可能性 对流感的反应将被评估为可用于增强治疗功效的新的潜在机制。在具体目标2中，研究了新型IKKβ抑制剂E6070（Riskai，Inc.）对 将在棉鼠中测试单独或与当前抗流感病毒疗法一起使用的流感病毒 (CR)第二种啮齿动物物种，其允许分析响应于非适应性人流感分离株感染的ALI。目的2还将在继发性葡萄球菌感染模型中比较Acetoran和E6070的CR （MRSA）肺炎后流感感染。最后，我们将评估阿托莫兰的相对有效性。 和E6070阻断由其他临床重要病原体或生物威胁病原体相关引起的ALI的能力 与人类的ALI（例如，土拉热弗朗西斯菌、肺炎链球菌、肺炎克雷伯菌、SARS-CoV和MERS-CoV），首先在小鼠中，如果有效，则在CR中。这些实验将挑战 TLR拮抗剂代表了一种基础广泛的治疗剂， 宿主对多种ALI诱导优先病原体的反应。

For decades, a “one bug, one drug” approach has characterized development of vaccines or treatments for specific infectious diseases. We propose a different approach based on the development of novel treatment of infectious diseases by capitalizing on common host innate immune responses that are triggered during infection by influenza and other priority pathogens. Influenza virus infects up to 5 million people yearly worldwide, killing as many as ~500,000. Our strong experimental evidence demonstrates that the potent TLR4 antagonist, Eritoran (Eisai, Inc.), as well as multiple other TLR4 antagonists, significantly decreased both acute lung injury (ALI) and mortality when administered therapeutically to influenza-infected mice. Eritoran not only blocks influenza-mediated release of host-derived ”danger-associated molecular patterns” (DAMPs), but also blunted DAMP-mediated TLR4 signaling in macrophages that normally results in a “cytokine storm.” While we have elucidated several novel mechanisms by which influenza mediates ALI and lethality that are counteracted by Eritoran therapy (e.g., release of host-derived DAMPS that signal through TLR4; increased tight-junction permeability leading to pulmonary edema; a role for IL-1α/β in lethality), our understanding of the overall innate immune signaling pathways that control influenza-induced ALI and Eritoran-mediated protection remains incomplete, necessitating further investigation to develop a highly efficacious host-directed therapy. Therefore, Specific Aim 1 will focus on the identification of innate immune mechanisms that underlie both influenza sensitivity and Eritoran-mediated protection. We will take advantage of genetically modified mouse strains to dissect the signaling pathways engaged. Whether TLR4 must be expressed on stromal and/or myeloid cells, the role of virus-induced epithelial cell necroptosis in DAMP release, mechanisms by which non-TLR4 PRRs contribute to influenza resistance/susceptibility, and the possibility that TLR2/TLR4 dimerization is required for the host response to influenza will be evaluated as novel potential mechanisms that can be exploited to enhance therapeutic efficacy. In Specific Aim 2, the therapeutic benefit of a novel IKKβ inhibitor, E6070 (Eisai, Inc.), against influenza, alone or in the presence of current anti-influenza antiviral therapies, will be tested in cotton rats (CR), a second rodent species that permits analysis of ALI in response to infection by non-adapted human influenza isolates. Aim 2 will also compare Eritoran and E6070 in CR in a model of secondary staphylococcal (MRSA) pneumonia following influenza infection. Lastly, we will assess the relative effectiveness of Eritoran and E6070 for the ability to block ALI caused by other clinically important or biothreat pathogens associated with ALI in humans (e.g., Francisella tularensis, Streptococcus pneumoniae, Klebsiella pneumoniae, SARS-CoV and MERS-CoV), first in mice, and, if effective, in CR. These experiments will challenge the overarching central hypothesis that TLR antagonists represent broad-based, therapeutic agents that mitigate pathologic host responses to multiple ALI-inducing priority pathogens.