Contribution of phospholipase A2 enzymes in the homeostasis of the immune system

磷脂酶 A2 对免疫系统稳态的贡献

• 批准号: RGPIN-2016-05830
• 负责人: Boilard, Eric
• 金额: $ 2.77万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=645728
• 关键词: Contribution; phospholipase; A2; enzymes; homeostasis

BACKGROUND***The immune system distinguishes the self from the non-self, preventing foreign organisms or other sort of insults from damaging the body. To ensure of its homeostasis, multiple mechanisms tightly regulate the immune system. It is now appreciated that a complex ecosystem of microorganisms, referred to as the microbiota, lives in symbiosis with mammals and modulates immune responses. In our NSERC program, we consider the role of bactericidal enzymes hydrolyzing phospholipids, called phospholipase A2 (PLA2), in the regulation of the immune system. ***HYPOTHESIS***More specifically in this renewal application, we hypothesize that a secreted form of PLA2 (sPLA2), called sPLA2 group IIA (sPLA2-IIA), modulates key regulatory events of the immune system. We will use genetically engineered mice and we will scrutinize the impact of sPLA2-IIA expression on the immune system in mice. As sPLA2-IIA is a highly potent bactericidal enzyme constitutively expressed in mucosae, we will further consider its role on the regulation of immune homeostasis through its activity on the host's commensal microbes. ******AIMS***To gain further insight into sPLA2 mechanism of action in immunity, we will investigate these following aims:******1. To characterize the impact of expression of sPLA2-IIA on immune homeostasis ***2. To determine the effect of the expression of sPLA2-IIA on the normal flora in mice***3. To examine mechanism(s) by which sPLA2-IIA expression modulates the immune homeostasis ******SCIENTIFIC APPROACH******The recent generation of mice deficient in specific sPLA2 isoforms provides a method for dissection of sPLA2 functions in vivo. We wish to highlight that a unique and powerful aspect of this proposal is the extensive array of ‘tools' available for our analyses. These include a substantial number of genetically modified mouse strains, shot-gun based mass-spectrometry approach for the complete assessment of mouse microbiota, systems for large data analysis, a series of recombinant proteins (native and targeted mutations), methods for quantifying sPLA2 isoform expression and eicosanoid species. Importantly, the PI and his team of collaborators have extensive experience with sPLA2, microbiome and immunologic approaches.******IMPACT***Although sPLA2 enzymes have been known for at least two decades, the recent development of transgenic and knockout mice is just starting to permit the delineation of their contribution to physiology. This unique research program will reveal the role of a prominent sPLA2 enzyme in immunity, considering its role in the equilibrium of the microbiota. **************

免疫系统将自我与非自我区分开来，防止外来生物或其他种类的侮辱损害身体。为了确保其稳态，多种机制紧密调节免疫系统。现在认识到，被称为微生物群的微生物的复杂生态系统与哺乳动物共生并调节免疫应答。在我们的NSERC计划中，我们考虑了水解磷脂的杀菌酶（称为磷脂酶A2（PLA 2））在免疫系统调节中的作用。* 假设 * 更具体地说，在本更新申请中，我们假设PLA 2的分泌形式（sPLA 2），称为sPLA 2 IIA组（sPLA 2-IIA），调节免疫系统的关键调节事件。我们将使用基因工程小鼠，我们将仔细研究sPLA 2-IIA表达对小鼠免疫系统的影响。由于sPLA 2-IIA是一种在粘膜中组成型表达的高效杀菌酶，我们将进一步考虑其通过对宿主体内微生物的活性调节免疫稳态的作用。** 目的 * 为了进一步了解sPLA 2在免疫中的作用机制，我们将研究以下目的：**1.描述sPLA 2-IIA表达对免疫稳态的影响 *2。确定sPLA 2-IIA表达对小鼠正常植物群的影响 *3.研究sPLA 2-IIA表达调节免疫稳态的机制 ** 科学方法 * 最近一代缺乏特定sPLA 2同种型的小鼠提供了一种在体内解剖sPLA 2功能的方法。我们希望强调的是，这一建议的一个独特和强大的方面是广泛的“工具”，可供我们的分析。 这些包括大量的遗传修饰的小鼠品系，用于小鼠微生物群的完整评估的基于鸟枪的质谱法，用于大数据分析的系统，一系列重组蛋白（天然和靶向突变），用于定量sPLA 2亚型表达和类花生酸种类的方法。重要的是，PI和他的合作者团队在sPLA 2，微生物组和免疫方法方面拥有丰富的经验。* 虽然sPLA 2酶已经知道了至少二十年，转基因和基因敲除小鼠的最新发展才刚刚开始允许描绘其对生理学的贡献。这项独特的研究计划将揭示一种突出的sPLA 2酶在免疫中的作用，考虑到它在微生物群平衡中的作用。**************