Mechanisms of Host Cell Modulation By Bacterial Effector Proteins

细菌效应蛋白调节宿主细胞的机制

• 批准号: RGPIN-2019-05772
• 负责人: DCosta, Vanessa
• 金额: $ 2.19万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744316
• 关键词: Mechanisms; Host; Cell; Modulation; Bacterial

In environmental, agricultural and domestic settings, bacteria form symbiotic relationships with plants, animals, and humans. From the perspective of the bacteria, this is often mediated by a specialized class of proteins called effectors, which are secreted from the microbe to interact with proteins in neighbouring organisms and affect their biological function. Bacterial effectors play important ecological roles, such as their contribution to nodule formation in plants. In agricultural and domestic settings, bacterial effectors play intrinsic roles in infection of animals and humans, ultimately contributing to the survival of the bacterium in the host organism. Identifying the host targets of bacterial effectors, and consequently determining their mechanisms of action, has proven to be challenging. Effectors typically function in a dynamic and transient manner against their targets. However, traditional interaction--based approaches to identify the underlying protein--protein interactions require the interaction to maintain intact throughout the lengthy experimental process. We recently adapted a strategy that involves irreversible enzymatic labeling of proximal proteins (BioID) for the study of host--microbe interactions, and performed a systematic analysis in comparison to the traditional interaction--based approach. Our research revealed that BioID represents an exceptional complementary tool for the study of host--microbe interactions, and is capable of identifying new and complex functioning targets. We have established a streamlined approach to study host--microbe interactions that we will extend to the investigation of diverse microbes. Currently, our focus is the environmental pathogen Salmonella enterica serovar Typhimurium, which has a broad host range that includes humans, livestock, rodents, birds and domestic animals. We will use our new approach to perform a complete BioID screen of Salmonella's 64 predicted effectors. A series of downstream strategies will be employed to identify and dissect the molecular mechanisms of the newly identified effector functions. To accomplish these goals, we will use genetic, biochemical, and cell biological approaches. In addition, fluorescence microscopy will allow us to monitor both host and microbe over time. Collectively, this research program will provide new mechanistic insights into our understanding of host--microbe relationships, and provide new tools to study host cell biology. Additionally, this research may uncover new fundamental biological processes that contribute to the host cellular immune response.

在环境、农业和家庭环境中，细菌与植物、动物和人类形成共生关系。从细菌的角度来看，这通常是由一种名为效应器的特殊蛋白质介导的，这种蛋白质从微生物中分泌出来，与邻近生物中的蛋白质相互作用，影响其生物功能。细菌效应物发挥着重要的生态学作用，如它们对植物根瘤形成的贡献。在农业和家居环境中，细菌效应器在动物和人类的感染中发挥着内在的作用，最终有助于细菌在宿主生物体中的生存。确定细菌效应物的宿主靶标，从而确定它们的作用机制，已被证明是具有挑战性的。效应器通常以动态和瞬时的方式对其目标起作用。然而，传统的基于相互作用的方法来确定潜在的蛋白质-蛋白质相互作用要求相互作用在漫长的实验过程中保持完整。我们最近采用了一种涉及近端蛋白不可逆酶标记(BioID)的策略来研究宿主与微生物的相互作用，并与传统的基于相互作用的方法进行了比较。我们的研究表明，BioID是研究宿主-微生物相互作用的一个特殊的补充工具，并能够识别新的和复杂的功能靶点。我们已经建立了一种简化的方法来研究宿主-微生物的相互作用，我们将扩展到对不同微生物的调查。目前，我们的重点是环境病原体肠炎沙门氏菌鼠伤寒沙门氏菌，它的宿主范围很广，包括人、牲畜、啮齿动物、鸟类和家畜。我们将使用我们的新方法对沙门氏菌的预测的效应器进行完整的生物ID筛查。将采用一系列下游策略来识别和剖析新发现的效应器功能的分子机制。为了实现这些目标，我们将使用遗传、生化和细胞生物学方法。此外，荧光显微镜将允许我们随着时间的推移同时监测宿主和微生物。总而言之，这项研究计划将为我们理解宿主-微生物关系提供新的机械性见解，并为研究宿主细胞生物学提供新的工具。此外，这项研究可能会发现有助于宿主细胞免疫反应的新的基本生物学过程。