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.

项目摘要产生抗体，完善其品质并创造持久的体液记忆是适应性的关键部分免疫。疫苗防止微生物的能力在这些过程的每个方面都借鉴，但即使对于某些批准且有用的疫苗，效率需要更好。据此，破译钥匙至关重要影响抗体（AB）质量的细胞和分子过程。主要的努力是针对识别细胞内传感器，中间代谢介体和适当代谢的方式改变免疫细胞分化或功能。早就知道营养不良会破坏免疫防御感染的防御能力以及一项工作表明蛋白质缺乏可能会降低有效的AB 回答。营养供应与细胞内传感器（例如MTORC1和编程）本质上有关免疫细胞中的细胞代谢。例如，孤立蛋白缺乏的实验模型具有记录的氨基酸静脉浓度下降（A.A.）和较低的MTORC1活性从营养不良的啮齿动物中孤立的器官。我们在B细胞中对MTORC1的工作发现抗体反应为猛禽的B细胞限制性单倍不可限度改变，部分降低的活性在大小上相似在蛋白质剥夺的情况下报道。此外，我们和其他人并行 - 发现免疫和形成生发中心后，白浆和淋巴卵形中的杂色缺氧。初步体外和体内实验提供了证据，表明（a）谷氨酰胺在物理浓度下非弹性跨性质的限制是完全有效切换到IgG1和血浆细胞分化的限制，并且（b）谷氨酰胺溶解（谷氨酰胺转化为谷氨酸，然后是α-酮戊二酸）可以限制这些过程。这些发现是该应用程序总体模型的前提：营养可能是以浓度增加或进一步降低的卵泡中存在改变抗体的性质它借鉴淋巴细胞增殖和功能的反应。根据AIM 1，我们将测试对AB的影响减少A.A.的响应成熟B细胞供应或利用。 AIM 2将确定后果 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，单独或具有降低的葡萄糖氧化能力。该模型的一个暗示是增加了循环A.A. - 或者即使只是谷氨酰胺 - 也可以增强免疫结果。在AIM 3中，我们将使用新确定的内分泌测试高氨基酸血症是否增加间质谷氨酰胺并产生更大的AB反应或体内记忆。作为实验的新颖方面，我们将利用成像中的最新开发质谱（IMS）评估选定淋巴微环境中谷氨酰胺和选定的代谢产物实验动物。拟议研究的预期结果和影响是，我们将（i）提供一个在将IMS应用于生物问题方面的突破性技术进步，（ii）阐明一个长期存在的问题在营养和免疫力的联系下，（iii）确定了增强抗体反应的新方法。