Host mechanisms of gut colonization by commensal bacteria that affect lifespan

项目摘要 肠道细菌与宿主组织相关联并改变宿主生理学，影响寿命和衰老。 某些类型的细菌，如乳酸杆菌，有益于健康，而其他细菌则会使健康退化。 我们的知识是宿主如何构建微环境， 特定细菌。特别是，哪些宿主细胞（Aim 1）、基因和分子（Aim 2）促进 特定细菌的定植？作为向前迈出的重要一步，该提案旨在调查 利用最近分离菌株研究果蝇中细菌定殖的宿主机制 从野生D.黑腹菌， 被发现在苍蝇肠道中的一个严格定义的物理空间中定居。L. plantarum是一种益生菌， 果蝇为研究人类的同源物提供了独特而强大的遗传资源 疾病基因该提案利用了几种独特的检测方法来识别宿主 介导细菌菌株特异性的机制，包括宿主细胞类型、基因和 招募和维持肠道细菌的分子。核心假设是， 果蝇前肠中的细胞类型产生一个“微生态位”：一个专门的化学和物理环境。 微环境，促进特定细菌的粘附和增殖， 主持人该提案旨在（i）使用单细胞RNA测序来识别特定的宿主细胞 类型和基因来创造这种特殊的微环境。这将使使用 果蝇遗传学（ii）通过细胞探索宿主组织抗性机制 周转和确定的细胞外基质的局部分泌。作为一个关键的测试， 假设，建议将审查L。植物种群动力学，使其 与龙的关系。通过对我国城市生态位建设的研究， 果蝇肠道，这项研究将建立一个新的范式，使审讯的 宿主和它们的宿主之间保守的分子和细胞相互作用， 宿主健康。该提案具有开发工具的转化潜力，以推动这些有益的 交互.

Project Summary Gut bacteria associate with host tissues and alter host physiology, impacting lifespan and aging. Some types of bacteria, such as Lactobacilli, benefit health while others degrade it. A key gap in our knowledge is how the host constructs microenvironments that coordinate colonization by specific bacteria. In particular, which host cells (Aim 1), genes, and molecules (Aim 2) promote colonization by specific bacteria? As an important step forward, this proposal aims to investigate host mechanisms of bacterial colonization in Drosophila melanogaster using recently isolated bacterial strains of Lactobacillus plantarum and Acetobacter from a wild D. melanogaster, which are found to colonize a tightly-defined physical space in the fly gut. L. plantarum, is a probiotic in humans, and the fly provides unique and powerful genetic resources to study homologs of human disease genes. This proposal harnesses several unique assays developed to identify host mechanisms that mediate commensal strain specificity, including the host cell types, genes and molecules that recruit and maintain commensal bacteria. The central hypothesis is that specific cell types in the fly foregut produce a "commensal niche": a specialized chemical and physical microenvironment that facilitates adhesion and proliferation of specific bacteria that may benefit the host. The proposal aims to (i) use single cell RNA sequencing to identify the specific host cell types and genes that create this specialized microenvironment. This will enable the use of Drosophila genetics to (ii) probe the mechanisms of host tissue maintainance through cell turnover and localized secretion of a defined extracellular matrix. As a critical test of the hypothesis, the proposal will examine the L. plantarum population kinetics that enable its association with the commensal niche. By studying commensal niche construction in the Drosophila gut, this research will establish a new paradigm that enables interrogation of the conserved molecular and cellular interactions between hosts and their commensals that influence host health. The proposal holds translational potential for developing tools to drive these beneficial interactions.