Mechanisms by Which Alcohol-Induced Dysbiosis Impairs Host Defense Against Klebsiella Pneumoniae

项目摘要/摘要：酒精使用障碍(AUD)是一个重大的全球健康负担。AUD是一种 已确定的细菌性肺炎的危险因素，每年约有310万人死亡。AUD患者 更频繁地感染高毒力呼吸道病原体，发病率和 这些感染导致的死亡率，肺炎克雷伯菌在AUDS患者中的比例过高。 AUDS患者中肺炎克雷伯菌的死亡率是其他病原体的两倍。此外， 临床前和临床研究表明，饮酒会扰乱正常的肠道微生物 社区(生物失调)，但还没有发表的数据将酒精介导的肠道生物失调与呼吸联系起来 宿主防御功能障碍，目前还没有人试图将酒精的直接影响从这些 由肠道生物失调引起的。我们已经开发了一个小鼠模型系统，使我们能够研究 酒精相关生物失调的免疫调节作用及肺炎克雷伯菌宿主反应的分离 直接或间接地由酒精相关的生物失调所介导。使用粪便转移的初步研究表明 用从酒精喂养的小鼠身上分离的微生物群重新克隆的酒精天真动物增加了易感性 与用对照微生物群重新克隆的小鼠相比，肺炎克雷伯菌。需要检验的总体假设 在这项拟议的研究中，酒精介导的生物失调增加了肠道炎症和通透性， 这会导致T细胞在肠道中的隔离，改变肺部特异性T细胞的运输，并增加 对肺炎克雷伯菌的敏感性。我将用代谢组学和免疫学来验证我的假设 接近。目的1将验证酒精代谢失调促进肠道炎症和通透性的预测。 我将利用粪便过继转移和细胞培养实验来确定微生物和代谢 促进肠道炎症和通透性的成分。目标2将研究酒精代谢失调的影响。 关于肠道T细胞的编程和隔离。我将使用T细胞领养转移实验 确定酒精代谢失调对呼吸道感染前T细胞定位/隔离的影响。 目的3将验证酒精代谢失调损害肺部特异性T细胞运输的预测。我会评估T细胞 过继转移到酒精幼稚动物体内的微生物和代谢物启动的T细胞的贩运 用酒精非生态菌或成对喂养的微生物群重新克隆。 拟议的研究将使用一种新的模型系统来阐明微生物区系在宿主免疫中的作用。 应对措施，特别是在急性尿毒症和呼吸道感染方面。这些研究的结果将提供 支持R01提交的数据，重点是酒精诱导的生物失调对免疫调节的影响 肠肺轴。UNMC提供的科学环境和研究基础设施将是 作为一名独立科学家，对我的成长和发展起到了重要作用。

Project Summary/Abstract: Alcohol use disorders (AUD) are a significant global health burden. AUDs are an established risk factor for bacterial pneumonia, which accounts for ~3.1 million deaths annually. AUD patients are more frequently infected with highly virulent respiratory pathogens and experience increased morbidity and mortality from these infections, with Klebsiella pneumoniae being overrepresented in patients with AUDs. Mortality from Klebsiella pneumonia in patients with AUDs is double that from other pathogens. Further, preclinical and clinical studies show that alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis), yet no published data exist linking alcohol-mediated intestinal dysbiosis with respiratory host defense dysfunction and no attempt has been made to isolate the direct effects of alcohol from those resulting from intestinal dysbiosis. We have developed a mouse model system that enables us to investigate the immune modulatory effects of alcohol-associated dysbiosis and isolate the host responses to K. pneumoniae mediated directly or indirectly by ethanol-associated dysbiosis. Preliminary studies using fecal transfer show that alcohol-naïve animals recolonized with microbiota isolated from alcohol-fed mice have increased susceptibility to K. pneumoniae compared to mice recolonized with a control microbiota. The overall hypothesis to be tested in the proposed study is that alcohol-mediated dysbiosis increases intestinal inflammation and permeability, which leads to intestinal sequestration of T-cells, altered lung specific T-cell trafficking, and increased susceptibility to Klebsiella pneumoniae. I will test my hypothesis using both a metabolomics and immunological approach. Aim 1 will test the prediction that alcohol-dysbiosis promotes intestinal inflammation and permeability. I will utilize fecal adoptive transfer and cell culture experiments to determine the microbial and metabolic constituents that promote intestinal inflammation and permeability. Aim 2 will examine the impact of alcohol-dysbiosis on intestinal T-cell programing and sequestration. I will use T-cell adoptive transfer experiments to determine the effects of alcohol-dysbiosis on the location/sequestration of T-cells prior to respiratory infection. Aim 3 will test the prediction that alcohol-dysbiosis impairs lung specific T-cell trafficking. I will assess T-cell trafficking using microbial and metabolite primed T-cells adoptively transferred into alcohol-naïve animals recolonized with an alcohol-dysbiotic or pair-fed microbiota. The proposed studies will use a novel model system to clarify the role of the microbiota in host immune responses, particularly with regard to AUDs and respiratory infection. The results from these studies will provide data to support an R01 submission focused on the immunomodulatory effects of alcohol-induced dysbiosis on the gut-lung axis. The scientific environment, and the research infrastructure provided by the UNMC will be instrumental in my growth and development as an independent scientist.