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

• 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
• 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

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.

项目摘要 氨基酸是至关重要的营养素，对支持免疫力也很重要。然而，我们有有限的 了解免疫挑战如何调节氨基酸的可用性，以及免疫细胞如何 有义氨基酸，并将信号传递给免疫应答。Rag-GTUNK最近被 被鉴定为关键氨基酸传感器，其主要将信号从氨基酸传递到 雷帕霉素（mTOR）复合物1（mTORC 1）在非造血细胞。然而，Rag-GTdR还调节 转录因子TFEB，HLH-亮氨酸拉链小眼症（MiT/TFE）家族成员 转录因子，其在B细胞中的功能仍然未知。此外，Rag-GT独立 mTORC 1激活已被确定。Rag-GT3和mTORC 1如何协调调节体液免疫 豁免问题没有得到解决。我们比较了Rag-GT α和mTORC 1在B细胞中的功能 使用基因敲除模型的体内应答。我们的数据显示，尽管Rag-GTdR和mTORC 1 Rag-GT3是全身免疫激发所必需的，而不是mTORC 1，对于体液免疫是至关重要的。 对呼吸道流感感染的反应。Rag-GTcycle和 mTORC 1与全身免疫和气道免疫之间的氨基酸利用率差异相关 流感感染。此外，我们发现Rag-GTPase抑制TFEB并促进自噬， 其与ERK激活相关，但在很大程度上独立于mTORC 1。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使得B细胞依赖于Rag- GTP酶-TFEB途径，用于GC反应和抗流感抗体产生。在目标1中，我们将首先测试 活病毒免疫攻毒的呼吸途径是否是Rag-GTT的决定因素 依赖，但mTORC 1独立的体液免疫。其次，我们将进一步研究时间和 免疫攻击期间氨基酸可用性的空间动态。最后，我们将测试饮食是否 氨基酸干预可提高机体抗呼吸道病毒感染的体液免疫。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-GT3促进GC反应和体液免疫的机制。我们将进一步描述 B细胞中Rag-GT3相互作用组的研究。我们的研究将定义一部小说 响应氨基酸可用性以促进B细胞活化的Rag-GTK-ERK-TFE B信号传导轴， 产生抗呼吸道病毒感染的抗体。