VIRULENCE REGULATION AND PROTECTIVE IMMUNITY IN KLEBSIELLA PNEUMONIA

项目总结 这份职业发展提案描述了一个为期5年的指导性研究项目，该项目将增强 肺炎克雷伯菌肺部致病机制及宿主免疫的认识 回应。该项目将建立在候选人在细菌学、革兰氏菌发病机制方面的背景基础上。 阴性生物和传染病。说明性和实践性培训的结合，详见 全面的职业发展计划，将为应聘者提供强化的肺部培训 免疫生物学、获得性免疫和细菌信号传递，以及方法学方面的技术培训，如 流式细胞术和芯片序列分析。 成功完成拟议的目标将使应聘者获得 获得独立资金和过渡为独立内科医生-科学家所需的技能。 候选人将受益于医学博士大卫·A·亨斯塔德和约翰·P·阿特金森的出色指导。 马里兰州在已建立的和新创建的小鼠模型中，亨斯塔德博士广泛地剖析了宿主病原体 革兰氏阴性细菌感染中的相互作用和宿主免疫反应，而阿特金森博士是一个世界- 著名免疫学家，在培训内科科学家方面有丰富经验。候选人获得支持 由一个世界级的咨询委员会，每个成员都是根据与研究相关的特定专业知识而选择的 建议书和职业发展计划。这项工作将在规模巨大的华盛顿大学 环境以其丰富的科学资源和丰富的医学科学家培养历史。 金黄色葡萄球菌感染，包括肺炎、尿路感染和血液感染，正在急剧上升。 住院患者的增加；疾控中心最近宣布，KP和其他碳青霉烯类细菌的感染- 耐药肠杆菌科(CRE)需要达到紧急威胁级别。两个重要的金黄色葡萄球菌毒力因子， 胶囊和1型菌毛在不同的宿主生态位中都是重要的，特别是在肺和尿路， 分别进行了分析。候选人将检验这一假设，即这些毒力因素是协调和相反的 监管，并将确定这一监管背后的机械性联系。候选人将决定如何 I型菌毛、它们的相转换膜、调节因子FimK和细菌第二信使环二GMP的作用 KP肺炎小鼠模型中KP的囊膜生产和下游毒力。 此外，尽管金黄色葡萄球菌的发病率和临床重要性，人们对自然保护知之甚少。 对KP的豁免权。使用一种新的Kp模型菌株，候选人的初步数据表明Kp 小鼠肺部的感染对随后的感染具有保护作用。淋巴细胞性浸润性病变 在这些受保护宿主的肺中可观察到可诱导的支气管相关淋巴组织。因此， 拟议的研究还将表征对KP肺炎的获得性免疫反应，以及 胶囊在诱导保护中的作用。这些研究可能确定细菌的抗毒力靶点 治疗方面，同时也为潜在的疫苗开发奠定了基础，以防止严重的KP感染。

PROJECT SUMMARY This career development proposal describes a 5-year mentored research project which will enhance our understanding of Klebsiella pneumoniae (Kp) pathogenesis in the lung and subsequent host immune response. The project will build upon the candidate's background in bacteriology, pathogenesis of Gram- negative organisms, and infectious diseases. A combination of didactic and practical training, detailed in the comprehensive career development plan, will provide the candidate with enhanced training in lung immunobiology, adaptive immunity, and bacterial signaling, and technical training in methodologies such as flow cytometry and ChIP-Seq. Successful completion of the proposed aims will enable the candidate to gain the skills required to secure independent funding and transition as an independent physician-scientist. The candidate will benefit from the superb mentorship of David A. Hunstad, MD, and John P. Atkinson, MD. In established and newly created murine models, Dr. Hunstad has extensively dissected host-pathogen interactions and host immune responses in Gram-negative bacterial infections, while Dr. Atkinson is a world- renowned immunologist with extensive experience in training physician-scientists. The candidate is supported by a world-class advisory committee, each member chosen for specific expertise relevant to the research proposal and career development plan. The work will take place in the tremendous Washington University environment with its abundant scientific resources and rich history in the training of physician-scientists. Kp infections, including pneumonia, urinary tract infection, and bloodstream infection, are sharply on the rise in hospitalized patients; CDC has recently declared that infections with Kp and other carbapenem- resistant Enterobacteriaceae (CRE) demand a threat level of urgent. Two important Kp virulence factors, capsule and type 1 pili, are known to be important in distinct host niches, specifically the lung and urinary tract, respectively. The candidate will test the hypothesis that these virulence factors are coordinately and inversely regulated, and will identify the mechanistic link underlying this regulation. The candidate will determine how type 1 pili, their phase switch fimS, regulator FimK, and the bacterial second messenger cyclic-di-GMP affect capsule production in Kp and downstream virulence in a murine model of Kp pneumonia. In addition, despite the prevalence and clinical importance of Kp, little is known about natural protective immunity against Kp. Using a new model strain of Kp, the candidate's preliminary data indicate that Kp infection of the lungs in mice is protective from subsequent infection. Lymphocytic infiltrates resembling inducible bronchus-associated lymphoid tissue are observed in the lungs of these protected hosts. Thus, the proposed research will also characterize the adaptive immune response to Kp pneumonia and the role of capsule in eliciting protection.These studies may identify bacterial targets amenable to anti-virulence therapeutics, while also laying the foundation for potential vaccine development to prevent serious Kp infection.