Gut Microbiota and Host Regulatory Cross-Talk in Pulmonary Fibrosis

项目摘要 特发性肺纤维化(Ipf)是一种进行性肺部疾病，目前尚无治愈方法。 了解发病机制。IPF导致生活质量显著下降、反复住院和IS 致命的。我们和其他人已经证明，肺免疫在IPF中调节失调。细菌和宿主 人体肠道环境--肠道微生物群--对人体免疫力有着深远的影响。胆量 微生物群是肺免疫的关键调节器，这是对几个 实验模型。在最近发表的一项关键发现中，我们表明无菌(GF)小鼠- 缺乏微生物组的实验小鼠免受肺纤维化相关死亡的保护。在人类中 IPF患者肺部细菌负荷预测死亡率与肺部细菌多样性相关 肺部发炎。虽然微生物组预测结果，但关键的调控相互作用 宿主、肺部和肠道微生物区系尚不清楚。 这一提议的中心假设是关键的肠道微生物区系，即双歧杆菌，起主导作用。 肺纤维化中的肺免疫调节，塑造宿主防御，相关炎症和 改良肺损伤后的实质修复。这项提议的理由是，这项工作将增强我们的 目前对IPF发病机制的认识以及进一步基于微生物组治疗的基础 慢性肺病。我们将通过以下实验目标来实现这一目标： 具体目标1：确定关键的双歧杆菌副产物和代谢物 应用生物前饮食改良、无菌(GF)和诺生素建立肺纤维化的临床前模型 小鼠，16S rRNA基因测序，功能元基因组学和代谢组学。 具体目标2：确定与宿主相关的细胞和分子机制 双歧杆菌利用临床前肺纤维化模型改善肺纤维化的预后 常规和生长因子来源的T细胞和IL-10转基因模型、T细胞过继转移和多色流动 细胞仪介导肺细胞免疫的表征。 具体目的3：确定特发性肺纤维化患者肠道微生物区系的免疫和纤维化作用。 来自IPF患者的肠道微生物区系将被识别并与疾病严重程度和临床相关 结果。GF小鼠将接受粪便微生物区系移植，样本来自人类患者 使用IPF。这些细菌将在体内进行研究，并在这个临床前模型中与肺纤维化相关。 这种翻译方法将使用先进的机械工具来1)提高我们对复杂结构的理解 在肺纤维化的临床前模型中发生的免疫-微生物群相互作用，2)识别可修改的宿主和 肺纤维化中的微生物区系相关靶点以及3)为基于微生物组的治疗提供基础 在慢性肺病中。

Project Summary Idiopathic pulmonary fibrosis (IPF) is a progressive pulmonary disorder with no known cure and poorly understood pathogenesis. IPF results in significant reductions in quality of life, recurrent hospitalizations and is fatal. We and others have shown that pulmonary immunity is dysregulated in IPF. The bacteria and host environment of the human gut - the gut microbiome - has a profound impact on human immunity. The gut microbiome is a key regulator of pulmonary immunity, a consistent biological observation across several experimental models. In a key finding, recently published, we have shown that germ free (GF) mice – experimental mice devoid of a microbiome – are protected from pulmonary fibrosis related mortality. In human patients with IPF, the bacterial burden of the lung predicts mortality and the lungs bacterial diversity correlates with pulmonary inflammation. While the microbiome predicts outcomes, key regulatory interactions between the host, lung and gut microbiota remain unknown. The central hypothesis of this proposal is that key gut microbiota, namely Bifidobacterium spp, act as master regulators of pulmonary immunity in lung fibrosis, shaping host defense, associated inflammation and modifying parenchymal repair after lung injury. The rationale for this proposal is that this work will augment our current knowledge of IPF pathogenesis and further the foundational basis for microbiome based therapies in chronic lung disease. We will accomplish this through the following experimental aims: Specific Aim 1: To determine key Bifidobacteria by-products and metabolites that contribute to outcomes in pre-clinical models of pulmonary fibrosis using pre-biotic diet modifications, germ free (GF) and gnotobiotic mice, 16S rRNA gene sequencing, functional metagenomics and metabolomics. Specific Aim 2: To determine the host related cellular and molecular mechanisms through which Bifidobacterium spp modify outcomes in pulmonary fibrosis using pre-clinical models of pulmonary fibrosis in conventional and GF derived T cell and IL-10 transgenic models, T cell adoptive transfer and multicolor flow cytometry mediated characterization of lung cellular immunity. Specific Aim 3: To determine the immunogenic and fibrogenic effects of gut microbiota from patients with IPF. Gut microbiota from patients with IPF will be identified and correlated with disease severity and clinical outcomes. GF mice will undergo fecal microbiota transplantation with samples derived from human patients with IPF. These bacteria will be studied in vivo and correlated with lung fibrosis in this pre-clinical model. This translational approach will use advanced mechanistic tools to 1) improve our understanding of complex immune-microbiota interactions that occur in pre-clinical models of lung fibrosis, 2) identify modifiable host and microbiota related targets in lung fibrosis and finally 3) advance the foundation for microbiome based therapies in chronic lung disease.