Context dependent amino acid availability and sensing determines humoral immunity

环境依赖性氨基酸可用性和传感决定体液免疫

基本信息

批准号：
10436678
负责人：
Hu Zeng
金额：
$ 47.08万
依托单位：
MAYO CLINIC ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-02-10 至 2027-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10436678
关键词：
2019-nCoV Address Allergens Amino Acids Antibodies Antibody Formation Antibody Therapy Autophagocytosis B-Cell Activation B-Lymphocytes COVID-19 Cells Complex Data Development Event Extracellular Signal Regulated Kinases FRAP1 gene Family Fatty Acids Genetic Glucose Guanosine Triphosphate Phosphohydrolases Humoral Immunities Immune Immune response Immunity Immunization In Vitro Infection Interferons Intervention Knock-in Mouse Knock-out Leucine Zippers Link Mediating Metabolic Metabolism Microphthalmos Modeling Molecular Molecular Target Nutrient Nutritional Pathway interactions Proteins Proteomics Reaction Regulation Research Respiratory syncytial virus Route Signal Transduction Signaling Molecule Structure of germinal center of lymph node Technology Testing Viral Respiratory Tract Infection Virus Virus Diseases Virus Replication airway immune response amino acid metabolism anti-influenza design dietary gain of function improved in vivo influenza infection influenzavirus loss of function member metabolomics mouse model novel pathogen programs respiratory response screening sensor transcription factor

项目摘要

Project Summary Amino acids are crucial nutrients that are also important to support immunity. Yet, we have limited understanding with regard to how immune challenges modulate amino acid availability, and how immune cells sense amino acid and transduce the signals to execute immune reponses. Rag-GTPase has recently been identified as a key amino acid sensor that mostly transduce signals from amino acids to mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) in non-hematopoietic cells. However, Rag-GTPase also modulates transcription factor TFEB, a member of the microphthalmia (MiT/TFE) family of HLH-leucine zipper transcription factors, whose functions in B cells remain unknown. Moreover, Rag-GTPase independent mTORC1 activation has been identified. How Rag-GTPase and mTORC1 coordinates to regulate humoral immunity has not been addressed. We compared the functions of Rag-GTPase and mTORC1 in B cell response in vivo using genetic knockout models. Our data showed that while both Rag-GTPase and mTORC1 are required for systemic immune challenges, Rag-GTPase, but not mTORC1, is critical for humoral immune response towards respiratory influenza infection. This divergent requirement between Rag-GTPase and mTORC1 is associated with differential amino acid availability between systemic immunization and airway influenza infection. Furthermore, we showed that Rag-GTPase suppresses TFEB and promotes autophagy, which is associated with ERK activation, but largely independent of mTORC1. Thus, we hypothesize that reduced availability of specific amino acids during respiratory viral infection renders B cells dependent on Rag- GTPase-TFEB pathway, for GC reaction and anti-influenza antibody production. In Aim 1, we will first test whether the respiratory route of live virus immune challenge is the determining factor for Rag-GTPase dependent, but mTORC1 independent, humoral immunity. Second, we will further investigate the temporal and spatial dynamics of amino acid availability during immune challenges. Finally, we will test whether dietary amino acid intervention can improve humoral immunity against respiratory viral infection. In Aim 2, we will utilize complementary loss-of-function and gain-of-function approaches to elucidate the downstream signaling mechanisms by which Rag-GTPase promotes GC reaction and humoral immunity. We will further characterize the Rag-GTPase interactome in B cells using unbiased proteomics approach. Our study will define a novel Rag-GTPase-ERK-TFEB signaling axis that respond to amino acid availability to promote B cell activation and antibody production against airway viral infection.

项目概要氨基酸是至关重要的营养素，对支持免疫力也很重要。然而我们的能力有限了解免疫挑战如何调节氨基酸可用性以及免疫细胞如何感知氨基酸并转导信号以执行免疫反应。 Rag-GTPase 最近被被确定为关键的氨基酸传感器，主要将氨基酸信号转导至氨基酸的机械靶点非造血细胞中的雷帕霉素 (mTOR) 复合物 1 (mTORC1)。然而，Rag-GTPase 也调节转录因子 TFEB，HLH-亮氨酸拉链小眼症 (MiT/TFE) 家族的成员转录因子，其在 B 细胞中的功能仍不清楚。此外，Rag-GTPase 独立 mTORC1 激活已被确定。 Rag-GTPase 和 mTORC1 如何协调调节体液免疫问题尚未得到解决。我们比较了B细胞中Rag-GTPase和mTORC1的功能使用基因敲除模型进行体内反应。我们的数据表明，虽然 Rag-GTPase 和 mTORC1 是全身免疫挑战所必需的，Rag-GTPase（而不是 mTORC1）对于体液免疫至关重要对呼吸道流感感染的反应。 Rag-GTPase 和 Rag-GTPase 之间的这种不同要求 mTORC1 与全身免疫和气道之间的氨基酸可用性差异相关流感感染。此外，我们发现 Rag-GTPase 抑制 TFEB 并促进自噬，它与 ERK 激活相关，但很大程度上独立于 mTORC1。因此，我们假设呼吸道病毒感染期间特定氨基酸的可用性降低，导致 B 细胞依赖于 Rag- GTPase-TFEB 途径，用于 GC 反应和抗流感抗体生产。在目标 1 中，我们将首先测试活病毒免疫攻击的呼吸道途径是否是Rag-GTPase的决定因素依赖但不依赖 mTORC1 的体液免疫。其次，我们将进一步研究时间和免疫挑战期间氨基酸可用性的空间动态。最后，我们将测试是否饮食氨基酸干预可提高体液免疫，抵抗呼吸道病毒感染。在目标 2 中，我们将利用互补的功能丧失和功能获得方法来阐明下游信号传导 Rag-GTPase 促进 GC 反应和体液免疫的机制。我们将进一步表征使用无偏蛋白质组学方法研究 B 细胞中的 Rag-GTPase 相互作用组。我们的研究将定义一部小说 Rag-GTPase-ERK-TFEB 信号轴响应氨基酸可用性，促进 B 细胞激活和产生抗气道病毒感染的抗体。