Investigations of the role of host controlled peptidoglycan recycling in the regulation of the pea aphid-Buchnera symbiosis

宿主控制的肽聚糖回收在豌豆蚜-Buchnera 共生调节中的作用研究

• 批准号: 9468212
• 负责人: Thomas E Smith
• 金额: $ 5.67万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-09 至 2020-09-08
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9468212
• 关键词: Affect; African Trypanosomiasis; Animal Model; Animals; Antibiotics; Aphids; Back; Bacteria; Binding; Biochemical; Biochemical Genetics; Biological Assay; Body cavities; Bordetella pertussis; Buchnera; Buchnera aphidicola; Cardiovascular Diseases; Cell Wall; Cell division; Cells; Chagas Disease; Communication; Development; Disease; Disease Vectors; Domestic Animals; Engineering; Enzymes; Equilibrium; Eukaryota; Gene Expression; Gene Expression Profile; Genes; Genetic; Genome; Genotype; Goals; Homeostasis; Human; Immunofluorescence Immunologic; In Vitro; Infection; Inflammatory Bowel Diseases; Insecta; Invaded; Investigation; Knowledge; Lead; Light; Link; Membrane; Microbe; Modeling; Neisseria gonorrhoeae; Nutritional; Obesity; Pathogenicity; Pathway interactions; Peptidoglycan; Phenotype; Pisum; Pisum sativum; Play; Population; Population Sizes; Prevention; Process; Prokaryotic Cells; Proteins; Proteomics; Recombinants; Recycling; Regulation; Role; Serratia; Signal Pathway; Small Interfering RNA; Structure; Substrate Specificity; Symbiosis; System; Testing; Variant; Vesicle; Vibrio fischeri; Work; base; body cavity; cell envelope; commensal microbes; experimental study; fitness; flexibility; gene function; gene product; genetic approach; genome-wide; gut microbiome; human disease; in vivo; insect disease; insight; microbial; microorganism interaction; new therapeutic target; novel; novel strategies; novel therapeutics; pathogen; pathogenic bacteria; response; tool; transcriptomics

Project Summary Animals live in close association with bacteria, including both beneficial symbionts and harmful pathogens. Understanding the nuances that enable hosts to respond differently to pathogenic versus beneficial interactions could enable therapies that specifically target pathogens. A fundamental interface between bacterial and animal cells is the bacterial cell wall. In particular, cell wall peptidoglycan (PG) is known to be a key molecule in the infection process, both for pathogens such as Bordetella pertussis and Neisseria gonorrhoeae and also for symbionts such as Vibrio fischeri. In the model symbiosis of the pea aphid, Acyrthosiphon pisum, with its bacterial symbiont, Buchnera aphidicola, key enzymes in the pathway for PG recycling are encoded in the host genome and are known to be specifically expressed in the cells that harbor the symbiotic bacteria, and similar observations have been made in other eukaryotic systems. The focus of this proposal is to test the novel hypothesis that host control of PG recycling is a key mechanism for host regulation of symbiont populations. We will test this hypothesis using novel biochemical and genetic approaches within the pea aphid system. Specifically, we hypothesize that variation in Buchnera abundance between aphids can be explained by differences in the level of host-derived PG gene expression, that the host employs proteins that alter the Buchnera cell wall, and that host control over Buchnera PG recycling establishes stability of Buchnera population sizes. Testing this hypothesis will shed light on how animals domesticate pathogenic bacteria and convert them into symbionts, and, more broadly, will expand our fundamental understanding of microbial interactions with animals, including humans. To define the role of PG recycling in the regulation of symbiosis, we will: 1) investigate whether PG- related host genes play a role in determining Buchnera population size, 2) determine how host PG-related genes interact functionally with the Buchnera cell wall, and 3) demonstrate the relationship between host PG genes and Buchnera regulation in vivo. To test this, we will quantify the differences in PG gene expression levels between aphid genotypes with high versus low Buchnera abundance, characterize how host gene products affect Buchnera PG in vitro, and interrogate PG gene functions in vivo, implementing novel genetic tools for the aphid-Buchnera system. We predict that aphids use PG genes to disrupt Buchnera PG recycling and halt cell division, enabling hosts to control symbiont abundance by negative regulation. Our genome-scale approaches will enable discovery of other potential genetic bases of symbiont control. Results of the proposed work will contribute significantly to our understanding of how animals interact with symbiotic bacteria and, more specifically, how hosts regulate symbionts. These findings may lead to novel drugs targeting bacterial symbionts of insect disease vectors, or to the development of antibiotics that do not harm beneficial symbionts.

项目摘要 动物与细菌密切相关，包括有益的共生体和有害 病原体。了解使宿主能够对致病性和有益的有益反应不同的细微差别 相互作用可以实现专门针对病原体的疗法。之间的基本接口 细菌和动物细胞是细菌细胞壁。特别是，已知细胞壁肽聚糖（PG）是 感染过程中的关键分子，既适用于病原体，例如百日咳和奈瑟氏菌 淋病，也适用于诸如Fibrio Fischeri之类的共生体。在豌豆蚜虫的模型中， Acyrthosiphon Pisum，及其细菌共生体，Buchnera蚜虫，PG途径中的关键酶 回收在宿主基因组中编码，已知在藏有的细胞中特异性表达 在其他真核系统中也对共生细菌和类似的观察结果进行了类似的观察。重点 建议是测试新的假设，即PG回收的宿主控制是宿主调节的关键机制 共生群体。我们将使用新颖的生化和遗传方法在内部检验这一假设 豌豆蚜虫系统。具体而言，我们假设蚜虫之间的布奇纳丰度变化可以 可以通过宿主衍生的PG基因表达水平的差异来解释，宿主采用蛋白质 这改变了布赫纳拉细胞壁，对buchnera pg回收的宿主控制确立了 Buchnera人口规模。检验该假设将阐明动物如何驯化致病性 细菌并将它们转化为共生体，更广泛地将我们的基本理解扩展 与包括人在内的动物的微生物相互作用。 为了定义PG回收在共生调节中的作用，我们将：1）研究PG-是否是否 相关的宿主基因在确定buchnera人口大小中发挥作用，2）确定宿主与PG相关的方式 基因与buchnera细胞壁功能相互作用，3）证明了宿主PG之间的关系 基因和buchnera在体内调节。为了测试这一点，我们将量化Pg基因表达的差异 宿主基因的表征如何 产品在体外影响Buchnera PG，并在体内询问PG基因的功能，实施新的遗传 蚜虫 - 布内拉系统的工具。我们预测蚜虫使用PG基因破坏Buchnera PG回收 和停止细胞分裂，使宿主能够通过负调节来控制共生体的丰度。我们的基因组规模 方法将能够发现共生控制的其他潜在遗传基础。提议的结果 工作将有助于我们对动物如何与共生细菌相互作用的理解以及更多 具体而言，主机如何调节共生体。这些发现可能导致针对细菌的新药物 昆虫疾病载体的共生体，或不损害有益共生体的抗生素的发展。