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: 10228362
• 负责人: Thomas E Smith
• 金额: $ 1.73万
• 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/10228362
• 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.

项目概要 动物与细菌生活密切相关，包括有益的共生体和有害的共生体 病原体。了解使宿主对致病性和有益性做出不同反应的细微差别 相互作用可以实现专门针对病原体的治疗。之间的基本接口 细菌和动物细胞是细菌的细胞壁。特别是，细胞壁肽聚糖（PG）被认为是一种 感染过程中的关键分子，适用于百日咳博德特氏菌和奈瑟氏菌等病原体 淋病菌以及费氏弧菌等共生菌。在豌豆蚜的共生模型中， Acyrthosiphon pisum 及其细菌共生体 Buchnera aphidicola 是 PG 途径中的关键酶 回收在宿主基因组中编码，并且已知在包含这些物质的细胞中特异性表达 共生细菌，并且在其他真核系统中也进行了类似的观察。本次的重点 该提案是为了检验新的假设，即宿主对PG回收的控制是宿主调节的关键机制 共生群体。我们将使用新的生化和遗传学方法来检验这一假设 豌豆蚜系统。具体来说，我们假设蚜虫之间 Buchnera 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，即宿主使用蛋白质 改变 Buchnera 细胞壁，并且宿主对 Buchnera PG 回收的控制建立了稳定性 布赫内拉种群规模。检验这一假设将揭示动物如何驯化致病菌 细菌并将其转化为共生体，更广泛地说，将扩大我们对细菌的基本理解 微生物与动物（包括人类）的相互作用。 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 相关宿主基因在确定 Buchnera 种群大小方面发挥着作用，2）确定宿主 PG 相关性如何 基因与 Buchnera 细胞壁发生功能性相互作用，并且 3) 证明了宿主 PG 之间的关系 基因和 Buchnera 体内调节。为了测试这一点，我们将量化 PG 基因表达的差异 具有高 Buchnera 丰度和低 Buchnera 丰度的蚜虫基因型之间的水平，表征宿主基因如何 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-Buchnera 系统的工具。我们预测蚜虫利用 PG 基因破坏 Buchnera PG 回收 并停止细胞分裂，使宿主能够通过负调节来控制共生体丰度。我们的基因组规模 这些方法将使发现共生体控制的其他潜在遗传基础成为可能。提议的结果 这项工作将极大地有助于我们了解动物如何与共生细菌相互作用，并且更多 具体来说，宿主如何调节共生体。这些发现可能会导致针对细菌的新药的出现 昆虫疾病媒介的共生体，或开发不损害有益共生体的抗生素。

项目成果

Horizontal-Acquisition of a Promiscuous Peptidoglycan-Recycling Enzyme Enables Aphids To Influence Symbiont Cell Wall Metabolism.

• DOI: 10.1128/mbio.02636-21
• 发表时间: 2021-12-21
• 期刊: mBio
• 影响因子: 6.4
• 作者: Smith TE;Lee M;Person MD;Hesek D;Mobashery S;Moran NA
• 通讯作者: Moran NA