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

• 批准号: 10707222
• 负责人: JULIE ZIKHERMAN
• 金额: $ 58.77万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 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/10707222
• 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; CD4 Positive T Lymphocytes; Cell Compartmentation; Cell Death Induction; 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; Ligands; Lymphocyte; Mediating; Molecular; Mus; NR4A1 gene; NR4A2 gene; Nuclear; Nuclear Family; Nuclear Hormone Receptors; Nuclear Receptors; Organ Transplantation; Orphan; Pattern; Peripheral; Phenocopy; Phenotype; Physiological; Play; Production; Proliferating; Publishing; Radiation Chimera; Regulation; Regulatory T-Lymphocyte; Reporter; Repression; Role; Signal Transduction; T cell anergy; T cell response; T-Cell Development; T-Lymphocyte; Testing; Therapeutic; Thymus Gland; Tissues; Transcriptional Regulation; Vaccination; anergy; antagonist; antigen-specific T cells; autoreactive T cell; chromatin remodeling; cytokine; defined contribution; exhaust; expectation; genetic approach; innovation; member; non-genomic; novel; novel therapeutics; preservation; programs; response; restraint; small molecule; thymocyte; transcription factor; transcriptome; transcriptome sequencing; tumor

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 由淋巴细胞中的抗原（Ag）刺激迅速诱导。尽管它们被认为充当配体- 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 开发出来，使它们可以成药。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、无反应性或衰竭性 T 细胞。由于表达模式重叠 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。因此，以前不可能揭露额外的冗余功能 该家族在胸腺选择期间和传统成熟 CD4 T 细胞 (Tconv) 中存在。这代表着一个重大差距 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 Treg 稳态。出乎意料的是，混合嵌合体同时含有 WT 和 Nr4a1-/- Nr4a3-/- (DKO) 骨髓 尽管 Treg 细胞充足，但仍会迅速产生抗核自身抗体 (ANA) 和全身性炎症性疾病 大部分是WT起源的隔间。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 缺乏，并且是 B 细胞外源性的。我们发现 DKO 胸腺细胞的阴性选择对 以细胞固有的方式受损。与自身反应性 T 细胞逃逸至外周一致，DKO CD4 表达无能表型和转录标记的 Tconv 细胞在这些嵌合体中积累。 然而，这些自身反应性 DKO 细胞仍然表现出过度增殖和 IL-2 产生， 表明功能性无反应是有缺陷的。因此，我们假设 NR4A 家族发挥细胞固有的作用， 但在中枢和外周 CD4 T 细胞耐受中的作用是多余的。为了检验这个假设： 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标。 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 增殖。我们将使用批量和单细胞基因组方法来定义 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。