Molecular Genetics of Innate Immunity in C. elegans

线虫先天免疫的分子遗传学

• 批准号: 7489461
• 负责人: Dennis H Kim
• 金额: $ 29.4万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7489461
• 关键词: Adaptor Signaling Protein; Bacteria; C-Type Lectins; Caenorhabditis elegans; Candidate Disease Gene; Cells; Classification; Co-Immunoprecipitations; Comparative Study; Data; Dissection; Family member; Fluorescence; Gene Family; Genes; Genetic; Genetic Screening; Genome; Goals; Green Fluorescent Proteins; Human; Immune; Immune response; Immunity; Immunocompromised Host; In Vitro; Infection; Insecta; Intestines; Invertebrates; MAP Kinase Gene; MAPK14 gene; Mammals; Mediating; Mediator of activation protein; Methodology; Methods; Microarray Analysis; Molecular Genetics; Natural Immunity; Nematoda; Organism; Orthologous Gene; Pathway interactions; Play; Protein Family; Proteins; RNA Interference; Range; Receptor Activation; Regulation; Reporter; Reporter Genes; Research Personnel; Resistance; Role; Signal Pathway; Signal Transduction; Site; Sorting - Cell Movement; Tertiary Protein Structure; Testing; Tissues; Toll-like receptors; Transgenic Organisms; antimicrobial; antimicrobial peptide; base; cell type; functional genomics; genetic analysis; in vivo; insight; member; mutant; pathogen; positional cloning; programs; promoter; receptor; response; sensor

DESCRIPTION (provided by applicant): Recent studies have revealed that key signaling pathways of mammalian innate immunity have ancient evolutionary origins evident in the immune response cascades of invertebrate organisms such as insects and nematodes. The long-term goal of this project is to carry out the comprehensive analysis of innate immunity in C. elegans, with the anticipation that the systematic study of immunity in this genetically tractable host organism will illuminate evolutionarily conserved mechanisms of pathogen recognition and defense in mammalian innate immunity. We have initiated a multi-pronged functional genomic approach to the study of C. elegans immunity. We identified a requirement for a conserved PMK-1 p38 MARK pathway and TIR-1, a conserved Toll-lnterleukin-1-Receptor (TIR) domain adaptor protein that appears to function upstream of the PMK-1 pathway. We have used genome-wide microarray analysis to identify candidate immune effectors under the regulation of the PMK-1 pathway. We have identified additional candidate immune signaling components that may converge on PMK-1 from a systematic RNAi-based screen. Based on these data, we have developed the specific hypothesis of this proposal, which is that pathogen infection activates a TIR-1-PMK-1 signaling cascade that confers immunity through the regulation of secreted antimicrobial factors at the site of infection. We propose three specific aims to define the mechanisms by which the TIR-1-PMK-1 pathway confers immunity. First, we will determine whether the PMK-1 MAPK pathway acts locally in cells at the site of infection or systemically in pathogen defense. Second, we will define the mechanisms regulated by PMK-1 that confer pathogen resistance by functional analysis of PMK-1 transcriptional targets. Third, we will define the mechanism of TIR-1 activation of the PMK-1 MAPK pathway in response to pathogen. We will dissect the functional domains of the TIR-1 protein and characterize interacting proteins, assign candidate genes from our RNAi screen to the TIR-1-PMK-1 pathway by genetic interaction analysis, and systematically identify additional genes required for TIR-1 activation of the PMK-1 pathway using complementary genetic methods. In summary, the p38 MAPK pathway constitutes a critical mediator of innate immunity that has been conserved from worms to humans. We anticipate that the genetic dissection, of the mechanisms of immunity mediated by the p38 MAPK ortholog, PMK-1, will provide important insights into the mechanisms of mammalian innate immunity, including the role of the mammalian TIR-1 ortholog, SARM.

描述（由申请人提供）：最近的研究表明，哺乳动物先天免疫的关键信号传导途径在无脊椎动物的免疫反应级联（如昆虫和线虫）的免疫反应级联中具有古老的进化起源。该项目的长期目标是对秀丽隐杆线虫的先天免疫进行全面分析，并期望系统地研究这种遗传处理的宿主有机体对哺乳动物先天免疫的病原体识别和防御的进化机制的机制将阐明进化保守的机制。我们为秀丽隐杆线虫免疫的研究启动了多管齐下的功能基因组方法。我们确定了保守的PMK-1 P38 MARK途径和TIR-1的需求，Tir-1是一种保守的Toll-lnterleukin-1-受体1-受体（TIR）域适配器蛋白，该蛋白似乎在PMK-1途径的上游起作用。我们已经使用了全基因组微阵列分析来鉴定PMK-1途径调节下的候选免疫效应子。我们已经确定了可能从系统的基于RNAi的屏幕上在PMK-1上收敛的其他候选免疫信号传导成分。基于这些数据，我们开发了该提案的特定假设，即病原体感染激活了TIR-1-PMK-1信号传导级联，该级联通过调节感染部位的分泌抗菌因子来赋予免疫力。我们提出了三个特定的目的，以定义TIR-1-PMK-1途径赋予免疫力的机制。首先，我们将确定PMK-1 MAPK途径是在感染部位还是在病原体防御中局部作用。其次，我们将定义由PMK-1调节的机制，该机制通过对PMK-1转录靶标的功能分析赋予病原体耐药性。第三，我们将定义响应病原体的PMK-1 MAPK途径的TIR-1激活机理。我们将通过遗传相互作用分析剖析TIR-1蛋白的功能结构域，并表征相互作用的蛋白质，将候选基因从RNAi筛选为TIR-1-PMK-1途径分配给TIR-1-PMK-1途径，并系统地确定使用互补遗传学方法的TIR-1激活PMK-1途径所需的其他基因。总而言之，p38 MAPK途径构成了从蠕虫到人类保存的先天免疫的关键介体。我们预计，p38 MAPK直系同源物PMK-1介导的免疫机制的遗传解剖将提供对哺乳动物先天免疫机制的重要见解，包括哺乳动物TIR-1直角SARM的作用。