Manipulating & imaging nutrient micro-milieux as B cells effect humoral immunity

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基本信息

批准号：
9889587
负责人：
Mark R Boothby
金额：
$ 54.25万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-12-01 至 2024-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9889587
关键词：
Affect Affinity Amino Acids Anatomy Animals Antibodies Antibody Response B Cell Proliferation B cell differentiation B-Lymphocytes Biological Blood Circulation Cell Differentiation process Cell physiology Cells Chromatin Complex Critical Illness Data Defect Development Diet Effectiveness Elements Endocrine Environment Epigenetic Process Equilibrium Experimental Models FRAP1 gene Gap Junctions Gene Expression Regulation Generations Glucagon Receptor Glucose Glutamates Glutaminase Glutamine Haptens Health Histones Human Humoral Immunities Hypoxia IgE IgG1 Image Immune Immune response Immunity Immunization Immunoglobulin Class Switching Impairment In Vitro Infection Link Lymphocyte Lymphocyte Function Lymphoid Lymphoid Follicle Lysine Malnutrition Malpighian corpuscles Mass Spectrum Analysis Mature B-Lymphocyte Measures Mediator of activation protein Memory Memory B-Lymphocyte Metabolic Metabolism Microanatomy Microbe Modeling Molecular Nature Nutrient Nutritional status Operative Surgical Procedures Organ Outcome Patients Pattern Permeability Physiological Plasma Cells Precursor B-Lymphoblast Process Protein Deficiency Proteins Raptors Regulation Reporting Rodent Scientist Signal Pathway Signal Transduction Spleen Structure of germinal center of lymph node T-Lymphocyte Testing Vaccination Vaccines Venous Work adaptive immunity alpha ketoglutarate base cell type chromatin modification density deprivation electric impedance experimental study genomic locus histone methylation in vivo interstitial loss of function lymph nodes lymphocyte proliferation microbiome novel novel strategies nutrition oxidation plasma cell differentiation sensor vaccine efficacy virtual

项目摘要

Project Summary Generating antibodies, refining their qualities, and creating durable humoral memory are crucial parts of adaptive immunity. The capacity of vaccines to protect against microbes draws on each facet of these processes, but even for some approved and useful vaccines the efficacy is needs to be better. Accordingly, it is vital to decipher key cellular and molecular processes that affect antibody (Ab) qualities. Major efforts are directed toward the identification of ways in which intracellular sensors, mediators of intermediary metabolism, and metabolites proper alter immune cell differentiation or function. It has long been known that malnutrition undermines immune defenses against infection, and a body of work has suggested that protein deficiency may decrease effective Ab responses. Nutrient supply is intrinsically linked to intracellular sensors such as mTORC1 and programming of cellular metabolism in immune cells. For instance, experimental models of isolated protein deficiency have documented decreases in venous concentrations of amino acids (a.a.) and lower mTORC1 activity in freshly isolated organs from the malnourished rodents. Our work on mTORC1 in B cells found antibody responses to be altered by B cell-restricted haplo-insufficiency of Raptor, with partially reduced activity similar in magnitude to that reported in the setting of protein deprivation. Moreover, we – and others in parallel – uncovered evidence of variegated hypoxia in the white pulp and lymphoid follicles after immunization and formation of germinal centers. Preliminary in vitro and in vivo experiments provide evidence that (a) glutamine, at the physiological concentration of non-inflamed interstitia, is limiting for fully efficient switching to IgG1 and for plasma cell differentiation, and (b) glutaminolysis (the conversion of glutamine to glutamate, and then α-ketoglutarate) can be limiting for these processes. These findings are the premise for the overarching model of this application: that nutrients may be present in follicles at concentrations where either increases or further decreases alter the nature of the antibody response as it draws on lymphocyte proliferation and function. Accordingly, in Aim 1 we will test the impact on Ab responses of reducing a.a. supply to or utilization by mature B cells. Aim 2 will identify consequences for metabolic and epigenetic programming of the B cells in which glutamine supply or glutaminolysis are restricted, alone or with reduced glucose oxidation capacity. An implication of the model is that increased circulating a.a. – or even just glutamine – could enhance outcomes of immunization. In Aim 3, we will use a newly identified endocrine approach to test if hyperaminoacidemia increases interstitial glutamine and yields greater Ab responses or humoral memory. As a novel facet of the experiments, we will leverage a state-of the-art development in imaging mass spectrometry (IMS) to assess glutamine and selected metabolites in selected lymphoid micro-environments of experimental animals. The expected outcome & impact of the proposed studies are that we will (i) provide a ground-breaking technical advance in application of IMS to biological problems, (ii) elucidate a long-standing issue at the nexus of nutrition and immunity, and (iii) identify a novel means of boosting antibody responses.

项目概要产生抗体、完善其品质以及创造持久的体液记忆是适应性的关键部分疫苗抵御微生物的能力依赖于这些过程的各个方面，甚至是免疫。对于一些已批准且有用的疫苗，其功效需要更好，因此，破译关键至关重要。影响抗体 (Ab) 质量的细胞和分子过程主要致力于识别细胞内传感器、中间代谢介质和代谢物适当的方式改变免疫细胞的分化或功能人们早就知道营养不良会破坏免疫。防御感染，大量工作表明蛋白质缺乏可能会降低有效抗体营养供应与细胞内传感器（例如 mTORC1）和编程有内在联系。例如，分离蛋白质缺乏的实验模型。据记录，新鲜血液中氨基酸 (a.a.) 的静脉浓度降低，mTORC1 活性降低我们对 B 细胞中 mTORC1 的研究发现，从营养不良的啮齿类动物中分离出的器官有抗体反应。被 Raptor 的 B 细胞限制性单倍体不足所改变，部分活性降低的程度与此类似此外，我们和其他人同时发现了蛋白质剥夺的证据。免疫后白髓和淋巴滤泡出现杂色缺氧并形成生发中心。初步的体外和体内实验提供了以下证据：(a) 生理浓度的谷氨酰胺非发炎间质的减少，限制了完全有效地转换为 IgG1 和浆细胞分化，并且 (b) 谷氨酰胺分解（谷氨酰胺转化为谷氨酸，然后转化为 α-酮戊二酸）可能会限制这些这些发现是该应用总体模型的前提：营养素可能是存在于囊泡中的浓度增加或进一步减少都会改变抗体的性质反应，因为它利用淋巴细胞增殖和功能。因此，在目标 1 中，我们将测试对 Ab 的影响。减少成熟 B 细胞的 a.a. 供应或利用的反应将确定其后果。 B 细胞的代谢和表观遗传编程，其中谷氨酰胺供应或谷氨酰胺分解受到限制，单独或降低葡萄糖氧化能力该模型的一个含义是增加循环a.a。即使只是谷氨酰胺 - 也可以增强免疫效果在目标 3 中，我们将使用新发现的内分泌激素。测试高氨基酸血症是否会增加间质谷氨酰胺并产生更大的抗体反应的方法或作为实验的一个新颖方面，我们将利用最先进的成像技术。质谱 (IMS) 评估选定淋巴微环境中的谷氨酰胺和选定代谢物拟议研究的预期结果和影响是，我们将 (i) 提供将IMS应用于生物问题的突破性技术进步，（ii）阐明了一个长期存在的问题结合营养和免疫，以及 (iii) 确定一种增强抗体反应的新方法。