HUMAN GENETIC VARIATION REGULATING SALMONELLA HOST-PATHOGEN INTERACTIONS AND DISEASE SUSCEPTIBILITY

调节沙门氏菌宿主-病原体相互作用和疾病易感性的人类遗传变异

基本信息

批准号：
10176138
负责人：
Dennis Chun-Yone Ko
金额：
$ 50.47万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-01 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10176138
关键词：
Affect Alleles B lymphocyte immortalization Bacteremia Cell membrane Cells Cessation of life Cholesterol Clinical Communicable Diseases Cultured Cells Data Data Set Disease Disease susceptibility Dissection Divalent Cations Docking Enteral Enterocytes Epithelial Cells Functional disorder Funding Gastroenteritis Gene Expression Genes Genetic Genetic Variation Genome Genotype Goals Guanosine Triphosphate Phosphohydrolases Histopathology Human Human Genetics Immune Immune response In Vitro Inbred Strains Mice Individual Infection Inflammation Knockout Mice Lead Measures Mediating Membrane Modeling Molecular Morbidity - disease rate Multi-Drug Resistance Mus Mutation Nutrient Oral Outcome Patients Phenotype Plasma Play Population Predisposition Production Regulation Resolution Resources Risk Role Salmonella Salmonella infections Salmonella typhimurium Signal Pathway System Systemic disease Testing Therapeutic Intervention Type III Secretion System Pathway Typhoid Fever Validation Variant Whole Organism base cytokine gastrointestinal epithelium genetic makeup genetic variant genome wide association study human disease human population study improved induced pluripotent stem cell infected B cell lambda Spi-1 lymphoblastoid cell line macrophage metal poisoning monocyte mortality mouse model non-typhoidal Salmonella novel novel therapeutic intervention oral infection pathogen polarized cell rho screening trait

项目摘要

Salmonellae cause an estimated 150 million cases of gastroenteritis and 25 million cases of invasive disease (enteric fever and non-typhoidal bacteremia), leading to 300,000 deaths per year. Findings based on inbred mouse strains and rare human mutations indicate that the clinical presentations and outcomes of salmonellosis are influenced by the host’s genetic makeup. However, we do not understand the impact of common, naturally occurring human genetic differences on Salmonella infections. Our long-term goal is to leverage high- throughput cellular phenotyping of infection and natural genetic diversity to define molecular parameters of susceptibility to human infectious diseases. While genome-wide association studies (GWAS) of enteric fever and bacteremia identified genetic differences regulating susceptibility, such studies are limited by high variability in patient exposure, pathogen genetic diversity, and a limited understanding of the pathophysiology of identified variants. We developed a complementary cellular GWAS approach (Hi-HOST: High-throughput Human in vitrO Susceptibility Testing; http://h2p2.oit.duke.edu) to perform high resolution analysis of human genetic differences that impact host-pathogen traits while enabling experimental dissection of these traits. In the previous funding period, we focused on human genetic variants that regulate Salmonella invasion of host cells. We identified a regulatory variant in VAC14 that modulates levels of plasma membrane cholesterol and thus limits the docking of the Salmonella SPI-1 type III secretion system to host cells. Humans with the high-invasion allele of VAC14 have increased risk of typhoid fever and bacteremia. The objectives of this application are to define and characterize human genetic differences that alter the full spectrum of Salmonella host-pathogen interactions and assess their impact on disease. Building from our unique resource of Hi-HOST cellular GWAS of Salmonella invasion, replication, and host cytokine levels, we have identified SNPs mediating susceptibility to infection phenotypes that will undergo experimental validation and mechanistic studies. We will determine how regulatory SNPs affecting ARHGEF26 and MCOLN2 expression impact Salmonella invasion and replication and the role these genes play during infection in mice. For ARHGEF26, a Rho GEF that stimulates Salmonella-induced membrane ruffling, our association data and experimental evidence indicate SNPs regulate ARHGEF26 expression to increase invasion dependent on the Salmonella effector sopB. For MCOLN2, we hypothesize that this divalent cation channel is a novel factor that regulates intracellular replication by modulating nutrient access, metal toxicity, and/or immune cell polarization. Using Arhgef26 and Mcoln2 mice, we will elucidate how altered expression of these genes regulates bacterial burden and immune response during infection. Finally, we will test whether SNPs identified by Hi-HOST are associated with enteric fever and bacteremia in humans. Revealing these mechanisms could lead to new therapeutic strategies for salmonellosis and other diseases impacted by the same genetic variants.

沙门氏菌估计导致 1.5 亿例胃肠炎和 2500 万例侵袭性疾病（肠热病和非伤寒菌血症），每年导致 300,000 人死亡。小鼠品系和罕见的人类突变表明沙门氏菌病的临床表现和结果受到宿主基因构成的影响但是，我们自然不了解常见的影响。我们的长期目标是利用高水平的沙门氏菌感染的基因差异。通过感染的细胞表型分析和自然遗传多样性来定义感染的分子参数对人类传染病的易感性，同时进行肠热病和全基因组关联研究（GWAS）。菌血症确定了调节易感性的遗传差异，但此类研究受到高变异性的限制患者暴露、病原体遗传多样性以及对已识别病原体的病理生理学了解有限我们开发了一种互补的细胞 GWAS 方法（Hi-HOST：高通量人类体外敏感性测试；http://h2p2.oit.duke.edu）对人类遗传差异进行高分辨率分析影响宿主病原体特征，同时能够对这些特征进行实验解剖。在此期间，我们重点研究了调节沙门氏菌入侵宿主细胞的人类遗传变异。 VAC14 中的调节变异可调节质膜胆固醇水平，从而限制对接沙门氏菌 SPI-1 III 型分泌系统对具有 VAC14 高侵袭等位基因的人类细胞的影响。伤寒和菌血症的风险增加。本申请的目的是定义和确定。描述改变沙门氏菌宿主病原体全谱的人类遗传差异相互作用并评估它们对疾病的影响。利用我们独特的 Hi-HOST 沙门氏菌入侵、复制和宿主细胞 GWAS 资源构建细胞因子水平，我们已经确定了介导对感染表型的易感性的 SNP，这些感染表型将经历我们将确定监管 SNP 如何影响 ARHGEF26。和 MCOLN2 表达影响沙门氏菌入侵和复制以及这些基因在沙门氏菌侵袭和复制过程中发挥的作用对于 ARHGEF26（一种刺激沙门氏菌引起的细胞膜褶皱的 Rho GEF），我们研究了小鼠感染的情况。关联数据和实验证据表明 SNP 调节 ARHGEF26 表达以增加入侵依赖于沙门氏菌效应器 sopB 对于 MCOLN2，我们发现该二价阳离子通道是一个。通过调节营养获取、金属毒性和/或免疫来调节细胞内复制的新因子使用 Arhgef26 和 Mcoln2 小鼠，我们将阐明这些基因的表达如何改变。最后，我们将测试是否已识别出 SNP。 Hi-HOST 的细菌与人类肠热和菌血症有关，揭示这些机制可能是这样的。为沙门氏菌病和受相同基因变异影响的其他疾病带来新的治疗策略。