Genetic susceptibility to F tularensis

对土拉菌的遗传易感性

• 批准号: 6718791
• 负责人: John W Hollingsworth
• 金额: $ 27.56万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-30 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6718791
• 关键词: Francisella tularensis; RNA interference; bactericidal immunity; gene expression; genetic mapping; genetic susceptibility; immunogenetics; laboratory mouse; macrophage; microarray technology; quantitative trait loci; small interfering RNA; tissue /cell culture; tularemia

DESCRIPTION (provided by applicant): Francisella tularensis is the causative organism of the disease tularemia. The extreme pathogenic and infectious properties of this organism, as well as its ease of dissemination, make it a plausible candidate for use in a biological weapon. F. tularensis can be rendered even more dangerous by its aerosolization and by transformation with plasmids encoding resistance to antibiotics. It is therefore imperative to explore novel therapies for inhaled F. tularensis that do not rely on the use of these drugs. Developing such therapies would be facilitated by an improved understanding of the host genes participating in the clearance of F. tularensis from the lungs of experimental mice. Toward that end, I propose to use two parallel gene identification strategies: quantitative trait locus (QTL) mapping, and microarray-based gene expression studies. Individually, each of these approaches yields more candidate genes than can be feasibly pursued within the time limits of this proposal. To overcome this problem, I will reduce the candidate gene number to a manageable level by selecting only those genes that are contained within identified QTL and that are induced by F. tularensis infection. This comparatively small subset is likely to contain genes causally associated with susceptibility to F. tularensis. These genes will be tested for their biologic relevance by selectively suppressing them in cultured macrophages using short interference RNA (siRNA). Macrophages transfected with gene-specific, siRNA-expressing plasmids will be compared to their untransfected counterparts for their abilities to support proliferation of F. tularensis in vitro. Biologically validated genes emerging from these studies will represent novel molecular targets whose actions might be manipulated by therapies designed to improve the innate immune response to F. tularensis.

描述（由申请人提供）：弗朗西斯氏菌是疾病的病因。该生物的极端致病性和感染性特性及其易于传播，使其成为生物武器中使用的合理候选人。 F. tularensis可以通过其雾化和用编码对抗生素耐药性的质粒转化而变得更加危险。因此，必须探索不依赖于这些药物使用的吸入f的新疗法。通过对参与实验小鼠肺部清除的宿主基因的了解，可以提高开发这种疗法。为此，我建议使用两种平行基因识别策略：定量性状基因座（QTL）映射和基于微阵列的基因表达研究。单独的，这些方法中的每一种都产生的候选基因要比在该提案的时间限制内可行的基因更多。为了克服这个问题，我将仅选择识别QTL中的那些基因并由F. tolarensis感染诱导的那些基因来将候选基因数减少到可管理的水平。这个相对较小的子集可能包含与f菌的易感性相关的基因。这些基因将通过使用短干扰RNA（siRNA）在培养的巨噬细胞中选择性抑制它们的生物学相关性进行测试。将用基因特异性，表达siRNA的质粒转染的巨噬细胞将其与未转染的对应物进行比较，因为它们在体外支持F. tularensis的增殖能力。从这些研究中出现的生物学验证的基因将代表新的分子靶标的，其作用可能通过旨在改善对f。tularensis的先天免疫反应的疗法来操纵。