Natural Killer Cell Immunity Induced by ß-1,3-Glucan

α-1,3-葡聚糖诱导的自然杀伤细胞免疫

• 批准号: RGPIN-2020-05285
• 负责人: Mody, Christopher
• 金额: $ 2.62万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716159
• 关键词: Natural; Killer; Cell; Immunity; Induced

The immune system has developed to maintain homeostasis while protecting the host from infectious microorganisms. It is now clear that environmental factors activate and shape immunity. -1,3-glucan is one such molecule that is both inhaled and consumed in dietary grains and microbes. Evidence shows that dietary -1,3-glucan activates immunity including natural killer (NK) cells; however, the mechanisms and their role in host defense development is unknown. The goal of this proposal is to understand how -1,3-glucan modulates and causes differentiation of NK cell immunity. Natural Killer (NK) cells are innate lymphocytes that directly kill pathogenic microorganisms, e.g., bacteria, parasites and fungi as well as tumor cells and virus-infected cells without prior stimulation. However, recent studies demonstrate that they can develop a memory-like property similar to adaptive immune cells such as T cells. Adaptive immune cells demonstrate enhanced responses to previously encountered pathogens that enhances their ability to clear invading microbial pathogens. We previously showed that NK cells directly kill Cryptococcus and Candida, environmental fungi that have the ability to disrupt homeostasis and cause pathology. Recently we determined that NKp30 is the NK cell pattern recognition receptor (PRR) that recognizes and mediates NK cell cytotoxicity against these fungi. Furthermore, we identified that -1,3-glucan, a pathogen-associated molecular pattern (PAMP) in the fungal cell wall is the ligand for NKp30, which mediates NK cell recognition and killing. Interestingly, we found that -1,3-glucan is not only critical for PRR-PAMP-mediated NK cell killing, but also able to enhance NK cell cytotoxicity against C. neoformans and C. albicans. Further experiments suggest that the -1,3-glucan-enhanced killing tapers off over few weeks after initial simulation and then showed greater NK cell killing at the fourth week, a similar phenomenon to adaptive immune recall responses. It remains unknown how -1,3-glucan enhances NK cell killing and whether it leads to an activation event, a differentiation event, or acquisition of memory that modulates NK cell immunity. In this proposal, we plan to use transgenic and/or humanized mice to determine whether -1,3-glucan enhances NK cell cytotoxicity and understand the NKp30 interaction with -1,3-glucan in the enhanced NK cell cytotoxicity. We will profile differential gene expression of NK cells in the -1,3-glucan-enhanced cytotoxicity using RNA-seq and mass cytometry. The ultimate goal of this program is to understand the mechanisms that -1,3-glucan-enhanced killing, and whether -1,3-glucan induces antigen specific NK cell clonal expansion and memory development or epigenetic change leading to enhanced NK cell cytotoxicity, and determine whether the enhanced NK cell cytotoxicity is specific to fungi or to a wider range of pathogenic microorganisms.

免疫系统已经发展到维持体内平衡，同时保护宿主免受感染性微生物的侵害。现在很清楚，环境因素激活和塑造免疫力。β-1，3-葡聚糖就是这样一种分子，它在膳食谷物和微生物中被吸入和消耗。有证据表明，饮食中的1，3-葡聚糖可激活免疫力，包括自然杀伤（NK）细胞;然而，其机制及其在宿主防御发展中的作用尚不清楚。本提案的目的是了解-1，3-葡聚糖如何调节和引起NK细胞免疫分化。 自然杀伤（NK）细胞是直接杀死病原微生物的先天淋巴细胞，例如，细菌、寄生虫和真菌以及肿瘤细胞和病毒感染的细胞。然而，最近的研究表明，它们可以开发类似于适应性免疫细胞（如T细胞）的记忆特性。适应性免疫细胞对先前遇到的病原体表现出增强的反应，这增强了它们清除入侵微生物病原体的能力。 我们以前表明，NK细胞直接杀死隐球菌和念珠菌，环境真菌，有能力破坏体内平衡，并导致病理。最近，我们确定NKp 30是NK细胞模式识别受体（PRR），识别和介导NK细胞对这些真菌的细胞毒性。此外，我们确定了真菌细胞壁中的病原体相关分子模式（PAMP）-1，3-葡聚糖是介导NK细胞识别和杀伤的NKp 30的配体。有趣的是，我们发现β-1，3-葡聚糖不仅对PRR-PAMP介导的NK细胞杀伤至关重要，而且能够增强NK细胞对C.新型隐球菌和白色念珠菌。进一步的实验表明，-1，3-葡聚糖增强的杀伤作用在初始模拟后的几周内逐渐减弱，然后在第四周显示出更大的NK细胞杀伤作用，这是一种与适应性免疫回忆反应相似的现象。目前尚不清楚-1，3-葡聚糖如何增强NK细胞杀伤，以及它是否导致激活事件、分化事件或获得调节NK细胞免疫的记忆。 在该提案中，我们计划使用转基因和/或人源化小鼠来确定-1，3-葡聚糖是否增强NK细胞的细胞毒性，并了解在增强的NK细胞细胞毒性中NKp 30与-1，3-葡聚糖的相互作用。我们将使用RNA-seq和质谱细胞术分析NK细胞在-1，3-葡聚糖增强的细胞毒性中的差异基因表达。该项目的最终目标是了解-1，3-葡聚糖增强杀伤的机制，以及-1，3-葡聚糖是否诱导抗原特异性NK细胞克隆扩增和记忆发育或表观遗传变化，从而导致增强的NK细胞细胞毒性，并确定增强的NK细胞毒性是否特异于真菌或更广泛的病原微生物。