IRON REGULATION & VIRULENCE--MYCOBACTERIUM TUBERCULOSIS

该候选人正在完成为期三年的传染病研究奖学金，并在过去两年致力于结核病的基础科学研究。该候选人尤其对研究结核的基因调控感兴趣，以阐明可能成为重要药物和疫苗靶点的毒力基因和蛋白质抗原。通过这项资助的研究，候选人希望成为学术医疗机构的初级教员，并继续利用分子生物学技术研究结核病的发病机制。候选人将与白喉铁依赖性调控的领导者John Murphy博士和开发了可重复的结核感染巨噬细胞模型的Richard Silver博士合作，获得成功完成该项目所需的协作资源。主办者William Bishai博士在分枝杆菌基因调控和结核病发病机制方面拥有完善的专业知识。为了补充她的研究，候选人每周将参加大约3小时的传染病和结核病相关会议。她还计划在医学院和公共卫生学院学习分子生物学、结核病、疫苗开发和免疫学课程。在抗生素耐药性和艾滋病毒感染的推动下，结核病感染的全球负担令人震惊。阐明新的抗菌剂和疫苗的毒力机制和蛋白质抗原已经走到了最前沿。铁是大多数生物生存所必需的营养物质，在多种重要传染病病原体的毒力中起着核心作用。该候选人将以杆状细菌铁依赖性DtxR调控子为模型，研究分枝杆菌同源物ideR及其调控子。初步结果表明，在小鼠模型中，一种不依赖铁的杆状细菌DtxR突变高抑制因子可以减弱结核分枝杆菌的毒力。已经构建了一个类似的分枝杆菌ideR突变体，并将在体外使用凝胶转移试验进行测试，并在小鼠和巨噬细胞模型中进行体内测试。利用DtxR/IdeR“铁盒”，一个存在于所有DtxR调控基因中的回文DNA结合序列，其他感兴趣的基因已经在计算机上被鉴定出来，并将被检查。阐明这种铁依赖性的内毒素调控子可能导致鉴定毒力决定因素，以及用于疫苗和治疗的新抗原。

The candidate is completing a three year infectious disease fellowship and has devoted the last 2 years to basic science research in tuberculosis. In particular, the candidate is interested in studying gene regulation in tuberculosis to elucidate virulence genes and protein antigens which may make important drug and vaccine targets. Through the research conducted under this grant, the candidate would like to establish herself as a junior faculty member at an academic medical institution and continue to pursue tuberculosis disease pathogenesis using molecular biologic techniques. In collaboration with Dr. John Murphy, a leader in iron-dependent regulons in diphtheria, and Dr. Richard Silver, who has developed a reproducible macrophage model of tuberculosis infection, the candidate will have the collaborative resources necessary for the successful completion of this project. The sponsor, Dr. William Bishai, has well-established expertise in mycobacterial gene regulation and tuberculosis disease pathogenesis. To complement her research, the candidate will attend approximately 3 hours per week of infectious disease and TB-related conferences. She also plans to take courses in molecular biology, tuberculosis, vaccine development, and immunology in the School of Medicine and the School of Public Health and Hygiene. Fueled by antibiotic resistance and HIV infection, the global burden of tuberculosis infection is staggering. The elucidation of virulence mechanisms and protein antigens for new antimicrobials and vaccines has moved to the forefront. Iron is an essential nutrient for the survival of most organisms and has played a central role in the virulence of multiple important infectious disease pathogens. Using the corynebacterial, iron- dependent DtxR regulon as a model, the candidate will study the mycobacterial homologue, ideR and its regulon. Preliminary results have shown that an iron-independent, corynebacterial DtxR mutant hyperrepressor attenuates Mycobacterium tuberculosis virulence in a murine model. A similar mutant of the mycobacterial ideR has been constructed and will be tested in vitro using a gel-shift assay, and in vivo in a murine and macrophage models. Taking advantage of the DtxR/IdeR "iron box", a palindromic DNA binding sequence present in all DtxR-regulated genes, other genes of interest have been identified in silico and will be examined. Elucidation of this iron-dependent IdeR regulon may lead to the identification of virulence determinants, and novel antigens for vaccines and therapeutics.