Regulation of CD4 T cell tolerance by the NR4A family of nuclear receptors

核受体 NR4A 家族对 CD4 T 细胞耐受性的调节

基本信息

批准号：
10599024
负责人：
JULIE ZIKHERMAN
金额：
$ 60.31万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
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：
2022-09-19 至 2027-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10599024
关键词：
Acute Agonist Anti-Inflammatory Agents Antigens Autoantibodies Autoantigens Autoimmune Responses B-Cell Activation B-Lymphocytes BCL2L11 gene Bacterial Artificial Chromosomes Biology Bone Marrow Bypass CBLB gene CD4 Positive T Lymphocytes Cell Death Cells Chimera organism Chronic Clonal Deletion Coupled DNA Binding Domain Data Disease Epigenetic Process Exhibits FOXP3 gene Family Family member Gene Expression Gene Expression Profile Genes Genetic Genetic Transcription Genomic approach Goals Homeostasis Immune Immune response Immunosuppression Impairment Inflammatory Interleukin-2 Knowledge Lead Ligands Lymphocyte Mediating Molecular Mus NR4A1 gene NR4A2 gene Nuclear Family Nuclear Hormone Receptors Nuclear Receptors Organ Transplantation Orphan Pattern Peripheral Phenocopy Phenotype Physiological Play Production Publishing Radiation Chimera Regulation Regulatory T-Lymphocyte Reporter Role Signal Transduction T cell anergy T cell response T-Cell Development T-Lymphocyte Testing Therapeutic Thymus Gland Tissues Transcriptional Regulation anergy antagonist antigen-specific T cells autoreactive T cell cancer vaccination chromatin remodeling cytokine defined contribution exhaust expectation genetic approach innovation member non-genomic novel novel therapeutics preservation programs response small molecule thymocyte transcription factor transcriptome transcriptome sequencing

项目摘要

Project Summary/Abstract This proposal’s long-term goal is to take advantage of the biology of the NR4A family of orphan nuclear hormone receptors to selectively manipulate antigen-specific T cell responses in immune-mediated diseases. NR4A members (NUR77, NURR1, and NOR1) are encoded by three genes (Nr4a1-3, respectively) that are rapidly induced by antigen (Ag) stimulation in lymphocytes. Although they are thought to function as ligand- independent, constitutively active transcription factors, small molecule agonist and antagonist ligands have been developed, rendering them druggable. We and others have shown that NR4A TF expression scales with the intensity of Ag stimulation, and are highly upregulated in thymocytes undergoing negative selection, in regulatory T cells (Tregs), as well as in self-reactive, anergic, or exhausted T cells. Due to an overlapping expression pattern and considerable structural homology in their DNA-binding domain, the NR4A TFs exhibit profound functional redundancy; thymic deletion of multiple - but not individual - NR4A family members (Nr4a1 and Nr4a3 >> Nr4a2, which is minimally expressed) results in severe Treg deficiency and a “scurfy-like” disease that phenocopies Foxp3-/- mice. Consequently, it has not been possible previously to unmask additional redundant functions of this family during thymic selection and in conventional mature CD4 T cells (Tconv). This represents a major gap in our knowledge that limits full therapeutic exploitation of these factors. Recently, we took advantage of both conditional genetic and bone marrow chimera strategies in order to preserve Treg homeostasis. Unexpectedly, mixed chimeras harboring both WT and Nr4a1-/- Nr4a3-/- (DKO) bone marrow rapidly develop anti-nuclear autoantibodies (ANAs) and a systemic inflammatory disease despite a replete Treg compartment of largely WT origin. This disease differs qualitatively from that seen in germline DKO mice with Treg-deficiency, and is B cell-extrinsic. We show that negative selection of DKO thymocytes is profoundly impaired in a cell-intrinsic manner. Consistent with escape of self-reactive T cells into the periphery, DKO CD4 Tconv cells expressing phenotypic and transcriptional markers of anergy accumulate in these chimeras. However, these self-reactive DKO cells nevertheless exhibit exaggerated proliferation and IL-2 production, suggesting that functional anergy is defective. We therefore hypothesize that the NR4A family play cell-intrinsic, but redundant, roles in both central and peripheral CD4 T cell tolerance. To test this hypothesis: In our first aim, we propose to define the role of the NR4A family in thymic negative selection in the face of both ubiquitous and tissue-restricted antigens, and to define the transcriptional targets that contribute to this function. In our second aim, we propose to isolate NR4A contributions to peripheral T cell tolerance, and to canonical features of mature CD4 T cell anergy - including impaired signal transduction, cytokine production, and proliferation. We will use both bulk and single cell genomic approaches to define the mechanism by which the NR4A family regulates the transcriptome and epigenetic profile of naïve and tolerant CD4 T cells.

项目概要/摘要该提案的长期目标是利用孤儿核激素 NR4A 家族的生物学优势受体选择性地操纵免疫介导疾病中抗原特异性 T 细胞反应。 NR4A 成员（NUR77、NURR1 和 NOR1）由三个基因（分别为 Nr4a1-3）编码，这三个基因分别是淋巴细胞中的抗原（Ag）刺激可快速诱导，尽管它们被认为具有配体功能。独立的、组成型活性转录因子、小分子激动剂和拮抗剂配体已被我们和其他人已经证明 NR4A TF 表达随 Ag 刺激的强度，并且在经历负选择的胸腺细胞中高度上调，在调节中 T 细胞 (Treg) 以及自身反应性、无能或耗尽的 T 细胞，由于重叠的表达模式。 NR4A TF 在其 DNA 结合域中具有相当大的结构同源性，表现出深刻的功能冗余；胸腺删除多个（但不是单个）NR4A 家族成员（Nr4a1 和 Nr4a3 >> Nr4a2，表达量最低）导致严重的 Treg 缺陷和表型复制的“类皮癣”疾病 Foxp3-/- 小鼠经过测试，以前不可能揭示出额外的冗余功能。这个家族在胸腺选择过程中和在传统的成熟 CD4 T 细胞 (Tconv) 中存在着巨大的差距。据我们所知，这限制了这些因素的充分治疗利用。最近，我们利用条件遗传和骨髓嵌合体策略来保存出乎意料的是，混合嵌合体同时含有 WT 和 Nr4a1-/- Nr4a3-/- (DKO) 骨髓。尽管 Tregs 数量充足，但仍会迅速产生抗核自身抗体 (ANA) 和全身性炎症性疾病这种疾病与在种系 DKO 小鼠中观察到的疾病有本质上的不同。 Treg 缺陷，并且是 B 细胞外源性的。我们表明，DKO 胸腺细胞的负选择具有深远的影响。 DKO CD4 以细胞固有的方式受损，与自身反应性 T 细胞逃逸到外周一致。 Tconv 细胞表达这些嵌合体中积累的无能的表型和转录标记。然而，这些自反应性 DKO 细胞仍然表现出过度的增殖和 IL-2 的产生，因此，我们发现 NR4A 家族发挥着细胞固有的作用。但在中枢和外周 CD4 T 细胞耐受中的作用是多余的为了检验这一假设：在我们的第一个目标中，我们建议定义 NR4A 家族在胸腺负选择中的作用。普遍存在的组织限制性抗原，并定义有助于此功能的转录靶点。在我们的第二个目标中，我们建议分离 NR4A 对外周 T 细胞耐受性和典型的 T 细胞耐受性的贡献。成熟 CD4 T 细胞无反应性的特征 - 包括信号转导受损、细胞因子产生和我们将使用批量和单细胞基因组方法来定义增殖机制。 NR4A 家族调节初始和耐受 CD4 T 细胞的转录组和表观遗传特征。