DNA induction of neutrophilic asthma

项目总结 中性粒细胞哮喘是重症哮喘的一个亚型，目前尚无安全有效的治疗方法。有一个 未得到满足的需要，描绘中性粒细胞哮喘的机制，并开发有针对性的有效治疗方法。 宿主细胞衍生的DNA存在于细胞外液和血清中。DNA代表危险信号(危险- 关联分子模式--DAMP)。最近的研究表明，细胞外的一个重要作用 DNA在介导病毒诱导的哮喘加重中的作用。我们提供了稳健的初步数据来证明 细胞外DNA水平增加，DNA传感器IFI16(干扰素-伽马诱导蛋白-16)和 中性粒细胞哮喘呼吸道DNA-IFI16途径驱动的细胞因子/趋化因子我们开发了一种 小鼠哮喘模型中，DNA在IL10限制的背景下诱导中性粒细胞炎症 呼吸道环境发炎。这种表型需要IFI16信号适配器刺激物的参与。基座 根据这些新的初步结果，我们假设细胞外DNA诱导中性粒细胞哮喘 在选择性抑制IL10的TNFSFs存在的情况下，通过IFI16-STING途径。中性粒细胞外 陷阱产生DNA，从而建立中性粒细胞哮喘的自我延续机制。在目标1下，我们 将研究细胞外DNA与人类中性粒细胞哮喘的相关性。我们将研究下一代 呼吸道细胞外DNA、IFI16和IL10抑制的TNFSFs-TNF和OX40L的激活及其意义 呼吸道的病理生理后果。我们将研究支气管肺泡灌洗(BAL)， 来自3个研究组的上皮细胞和活检标本：1)中性粒细胞(有嗜酸性粒细胞和不嗜酸性粒细胞) 哮喘；2)非中性粒细胞(有无嗜酸性)哮喘；以及3)疾病对照。我们将描绘出 IFI16在DNA处理中的还原模型中的作用和重要性 呼吸道巨噬细胞和单核细胞。在目标2下，我们将研究胞外DNA- 诱导小鼠中性粒细胞哮喘。我们将阐明IL10和TNFSFs(肿瘤坏死因子和OX40L)在 在小鼠呼吸道中，将DNA诱导的防御程序切换为中性炎症程序。我们 将确定IFI204(小鼠IFI16同源基因)和刺痛在中性粒细胞炎症中的作用。我们会 研究细胞外DNA去除对小鼠中性粒细胞哮喘持续状态的影响。这个项目是 重要的是，它发现了中性粒细胞哮喘的一种新的DNA-IFI16刺痛机制，并评估了 在一项临床前研究中，DNA和刺痛抑制剂以及DNA清除剂的治疗效果。

PROJECT SUMMARY Neutrophilic asthma is a subtype of severe asthma, which has no safe and effective therapy. There is an unmet need to delineate the mechanism of neutrophilic asthma and develop targeted and effective therapies. Host cell-derived DNA is present in the extracellular fluid and serum. DNA represents a danger signal (danger- associate molecular pattern-DAMP) for host cells. Recent studies suggest an important role for extracellular DNA in mediating virus-induced asthma exacerbation. We present robust preliminary data demonstrating increased levels of extracellular DNA, the DNA sensor IFI16 (Interferon-gamma induced protein-16) and the DNA-IFI16 pathway-driven cytokines/chemokines in the airways from neutrophilic asthma. We developed a mouse model of asthma where DNA induces neutrophilic inflammation in the context of an IL10-constrained inflamed airway milieu. This phenotype requires the participation of the IFI16 signaling adapter STING. Based upon these novel preliminary results we hypothesize that extracellular DNA induces neutrophilic asthma through the IFI16-STING pathway in the presence of select IL10-suppressive TNFSFs. Neutrophil extracellular traps generate DNA, which establishes a self-perpetuated mechanism of neutrophilic asthma. Under Aim 1 we will examine the relevance of extracellular DNA for human neutrophilic asthma. We will study the generation of airway extracellular DNA, activation of IFI16 and IL10-suppressive TNFSFs—TNF and OX40L and their pathophysiological consequences in the airways. We will study bronchoalveolar lavage (BAL), bronchial epithelial cells and biopsy specimens from 3 study groups: 1) Neutrophilic (with and without eosinophilic) asthma; 2) Non-neutrophilic (with and without eosinophilic) asthma; and 3) Disease controls. We will delineate the function and importance of IFI16 for proneutrophilic biomolecules in a reductionist model in DNA-treated airway macrophages and blood monocytes. Under Aim 2 we will study the mechanism of extracellular DNA- induced neutrophilic asthma in mice. We will elucidate the role of IL10 and TNFSFs (TNF and OX40L) in switching the DNA-induced defensive program to a neutrophilic inflammation program in mouse airways. We will establish the role of IFI204 (the mouse IFI16 ortholog) and STING in neutrophilic inflammation. We will study the effect of removal of extracellular DNA on persistence of neutrophilic asthma in mice. This project is important because it uncovers a novel DNA-IFI16-STING mechanism of neutrophilic asthma and assesses the therapeutic benefits of DNA and STING inhibitors, and DNA scavengers in a preclinical study.