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: 9752631
• 负责人: Thomas E Smith
• 金额: $ 6.37万
• 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 2020-12-08
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9752631
• 关键词: Affect; African Trypanosomiasis; Animal Model; Animals; Antibiotics; Aphids; Back; Bacteria; Binding; Biochemical; Biochemical Genetics; Biological Assay; Bordetella pertussis; Buchnera; Buchnera aphidicola; Cardiovascular Diseases; Cell Wall; Cell division; Cells; Chagas Disease; Communication; Development; Disease; 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 bacteria; experimental study; fitness; flexibility; gene function; gene product; genetic approach; genome-wide; gut microbiome; human disease; in vivo; insect disease vector; insight; microbial; microorganism interaction; new therapeutic target; novel; novel strategies; novel therapeutics; pathogen; pathogenic bacteria; response; symbiont; 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，既包括有益的共生体，也包括有害的共生体 病原体。了解使宿主对致病和有益做出不同反应的细微差别 相互作用可以使专门针对病原体的治疗成为可能。这是一个基本的界面， 细菌和动物细胞是细菌的细胞壁。特别是，细胞壁肽聚糖(PG)是一种已知的 感染过程中的关键分子，包括百日咳杆菌和奈瑟氏菌等病原体 淋病和共生菌，如费氏弧菌。在豌豆蚜虫的共生模式中， 豌豆弯管吸虫及其细菌共生体--Aphidicola，PG途径中的关键酶 循环是在宿主基因组中编码的，并已知在含有 共生细菌，在其他真核系统中也进行了类似的观察。这件事的重点是 这项提议是为了检验新的假设，即PG循环的宿主控制是宿主调控的关键机制 共生体种群。我们将使用新的生化和遗传方法来检验这一假设 豌豆蚜虫系统。具体地说，我们假设蚜虫之间布赫尼拉丰度的差异可以 可以通过宿主来源的PG基因表达水平的差异来解释，即宿主利用蛋白质 这改变了Buchnera细胞壁，并且宿主对Buchnera PG循环的控制建立了稳定性 布赫内拉的人口规模。检验这一假说将有助于阐明动物是如何驯化病原体的 细菌，并将它们转化为共生体，更广泛地说，将扩大我们对 微生物与包括人类在内的动物的相互作用。 为了明确PG循环在调节共生中的作用，我们将：1)调查PG- 寄主相关基因在决定Buchnera种群大小中起作用，2)决定寄主PG与 基因与Buchnera细胞壁在功能上相互作用，以及3)证明了宿主PG与 基因与体内的Buchnera调控。为了测试这一点，我们将量化PG基因表达的差异 具有高和低Buchnera丰度的蚜虫基因型之间的水平，表征寄主基因 产品在体外影响Buchnera PG，并在体内询问PG基因功能，实现新的遗传 用于蚜虫-布赫内拉系统的工具。我们预测，蚜虫使用PG基因来破坏Buchnera PG的循环 并停止细胞分裂，使宿主能够通过负调控来控制共生菌的丰度。我们的基因组规模 这些方法将使发现共生菌控制的其他潜在遗传基础成为可能。建议的结果 这项工作将大大有助于我们理解动物如何与共生细菌相互作用，以及更多 具体地说，就是寄主如何管理共生体。这些发现可能导致针对细菌的新型药物的开发 昆虫疾病媒介的共生体，或不损害有益共生体的抗生素的开发。