Caenorhabditis elegans infection model for Coxiella burnetii

伯内氏柯克斯体的秀丽隐杆线虫感染模型

基本信息

批准号：
9221965
负责人：
Michael F Minnick
金额：
$ 18.13万
依托单位：
UNIVERSITY OF MONTANA
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-02-15 至 2019-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9221965
关键词：
Acute Address Adult Aerosols Affect Animal Model Animals Architecture Bacteria Bacterial Infections Bioinformatics Caenorhabditis elegans Categories Cavia Cells Centers for Disease Control and Prevention (U.S.)Characteristics Chronic Chronic Hepatitis Classification Clinical Complement Containment Coupled Coxiella Coxiella burnetii Culture Media Development Endocarditis Environment Eukaryota Exhibits Future Genes Goals Hepatitis High-Throughput Nucleotide Sequencing Housing Human Image Enhancement Immune Immune response Immunologics Individual Infection Innate Immune Response Intestines Invertebrates Laboratories Larva Libraries Life Longevity Maintenance Malaise Messenger RNA MicroRNAs Midgut Minority Modeling Molecular Mus Mutagenesis Nature Nematoda Organism Pathogenesis Pathology Perianal region structure Phenotype Phylogenetic Analysis Pneumonia Predisposition Process Production Protocols documentation Pulmonary Inflammation Q Fever RNA Interference Reporting Research Role Shuttle Vectors Signal Pathway System Technology Transcript Vertebrates Virulence Virulence Factors axenic culture bacterial fitness cost design feeding fitness flu genetic manipulation high throughput screening innate immune function mutant nonhuman primate novel null mutation pathogen public health relevance screening transcriptome transcriptome sequencing transmission process

项目摘要

DESCRIPTION (provided by applicant): Coxiella burnetii is an extremely infectious, intracellular bacterium that causes Q fever in humans and is classified as a select agent. Q fever typically presents as a debilitating, flu-like illness accompanied by pneumonia or hepatitis, but in a minority of cases a severe, chronic infection occurs with life-threatening endocarditis as the predominant manifestation. Little is known about Coxiella's virulence determinants or how the bacterium subverts the host cell, despite the central role for these factors and activities in the pathogen's survival. Our overall goals are to identify novel virulence determinants of C. burnetii and characterize the host's innate immune response against the bacterium during infection. To that end, we recently developed a novel animal model for Coxiella infection in Caenorhabditis elegans. When C. elegans nematodes feed on C. burnetii, the intestines become persistently colonized. Moreover, infection significantly decreases the worm's lifespan and produces a visible and pronounced pathology (deformed anal region or DAR). Previous reports showing that virulence factors identified in the C. elegans infection model are similarly utilized in higher-order hosts and that signaling pathways of C. elegans' innate immune response (IR) against pathogens are conserved in higher eukaryotes, underscores the value of this model for investigating human pathogens. We hypothesize that the C. elegans model of infection can be utilized in a high-throughput fashion to identify novel virulence factors of Coxiella and to analyze effectors of the worm's innate immune response against this enigmatic bacterium. To address the hypothesis, Aim 1 will screen a library of C. burnetii Himar1 TnA7 mutants for reduced fitness in C. elegans to identify potential virulence factors. Once identified, the corresponding Coxiella genes will be investigated using molecular Koch's postulates to verify their role in potentiating virulence. TNSeq will also be done to analyze the contribution of every mutagenized gene in the Coxiella library to bacterial fitness over the course of infection. I Aim 2, we will analyze the "infection-specific" transcriptome of C. elegans by RNASeq to identify innate IR effectors against C. burnetii. In Aim 3, we will investigate the functionality of these innate IR effectors using a combination of RNAi and mutant strains of C. elegans to investigate host susceptibility to a Coxiella infection, relative to wild-type nematodes. In the end, this stud will significantly move the field forward by: a) identification and analysis of novel Coxiella virulence determinants, b) providing a new animal model of C. burnetii infection that will facilitae screening for virulence factors and other desirable phenotypes, and c) characterizing potentially novel, innate IR effectors that are utilized by a host to counter the pathogen.

描述（由申请人提供）：伯内特立克次体是一种传染性极强的细胞内细菌，可引起人类 Q 热，被归类为选择性病原体 Q 热通常表现为一种令人衰弱的流感样疾病，伴有肺炎或肝炎，但在少数情况下，会出现严重的慢性感染并伴有危及生命的心内膜炎，例如尽管这些因素和活动在病原体的生存中发挥着核心作用，但我们对柯克斯体的毒力决定因素或细菌如何破坏宿主细胞知之甚少。为此，我们最近开发了一种新的秀丽隐杆线虫感染动物模型。线虫以伯内特线虫为食，肠道内持续定植，感染会显着缩短线虫的寿命，并产生明显的病变（肛门区域变形或 DAR）。秀丽隐杆线虫感染模型在高等宿主中也有类似的应用，并且秀丽隐杆线虫针对病原体的先天免疫反应（IR）的信号通路在高等宿主中是保守的。真核生物，强调了该模型对于研究人类病原体的价值，我们追求线虫感染模型可以以高通量方式用于识别柯克斯体的新毒力因子并分析该蠕虫针对其先天免疫反应的效应器。为了解决这一假设，Aim 1 将筛选 C. burnetii Himar1 TnA7 突变体文库，以降低秀丽隐杆线虫的适应性。确定潜在的毒力因素。将使用分子科赫假设来研究相应的柯克斯体基因，以验证它们在增强毒力中的作用，还将进行 TNSeq 来分析其贡献。在目标 2 中，我们将通过 RNASeq 分析秀丽隐杆线虫的“感染特异性”转录组，以识别针对伯内特秀丽隐杆线虫的先天 IR 效应子。我们将使用 RNAi 和秀丽隐杆线虫突变株的组合来研究这些先天 IR 效应器的功能，以研究宿主对 Coxiella 感染的敏感性，相对于最后，该种马将通过以下方式显着推动该领域的发展：a）新的柯克斯体毒力决定因素的鉴定和分析，b）提供一种新的伯内特柯克斯体感染动物模型，这将有助于筛选毒力因子和其他所需的表型，以及 c) 表征宿主用来对抗病原体的潜在新颖的先天 IR 效应器。

项目成果

期刊论文数量（1）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A CsrA-Binding, trans-Acting sRNA of Coxiella burnetii Is Necessary for Optimal Intracellular Growth and Vacuole Formation during Early Infection of Host Cells.

伯内氏立克次体的 CsrA 结合、反式作用 sRNA 对于宿主细胞早期感染期间的最佳细胞内生长和液泡形成是必要的。

DOI：
发表时间：
2019
期刊：
影响因子：
3.2
作者：
Wachter, Shaun;Bonazzi, Matteo;Shifflett, Kyle;Moses, Abraham S;Raghavan, Rahul;Minnick, Michael F
通讯作者：
Minnick, Michael F