Epigenetic imprinting of follicular helper T cell fate and function in lupus

狼疮滤泡辅助 T 细胞命运和功能的表观遗传印记

• 批准号: 9974459
• 负责人: TERRI M. LAUFER
• 金额: $ 74.85万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-10 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9974459
• 关键词: ATAC-seq; Affect; Affinity; Antibodies; Antigen Presentation; Appearance; Autoantibodies; B-Lymphocytes; BLR1 gene; Biology; CD4 Positive T Lymphocytes; Cell Differentiation process; Cell Lineage; Cell physiology; Cells; Cellular biology; Chromatin; Clinic; Clinical; Code; DNA; Data; Defect; Development; Diagnostic; Disease; Epigenetic Process; Flow Cytometry; Future; Gene Expression; Generations; Genetic; Genetic Predisposition to Disease; Genetic Risk; Genetic Transcription; Health; Helper-Inducer T-Lymphocyte; Human; Immunoglobulin Class Switching; Immunologics; Infection; Interleukin-17; Knowledge; Lupus; Lymphocytic choriomeningitis virus; Lymphoid; Lymphoid Tissue; Maintenance; Maps; Mediating; Metabolic Pathway; Molecular; Mouse Strains; Mus; Newly Diagnosed; Pathogenicity; Pathology; Pathway interactions; Patients; Phenotype; Predisposition; Process; Production; Publishing; Reaction; Regulator Genes; Regulatory Element; Rheumatology; SLEB1 gene; Secondary to; Single Nucleotide Polymorphism; Single Nucleotide Polymorphism Map; Site; Specificity; Specimen; Structure of germinal center of lymph node; Susceptibility Gene; System; Systemic Lupus Erythematosus; T-Lymphocyte; T-Lymphocyte Subsets; Therapeutic Intervention; Tissue Differentiation; Tonsil; Tumor stage; chronic graft versus host disease; epigenome; epigenomics; experimental study; genome wide association study; imprint; improved; lupus prone mice; lymph nodes; mouse model; novel; peripheral blood; prevent; programmed cell death protein 1; programs; targeted biomarker; transcription factor

ABSTRACT The anti-nuclear autoantibodies (ANA) present in lupus are high-affinity, class-switched Abs that arise through T cell-dependent germinal center (GC) reactions. GC development and persistence is dependent on help from Follicular Helper CD4+ T cells (TFH). Although aberrant development and function of TFH drive disease in both SLE patients and murine models of lupus, the molecular and cellular pathways that initiate and reinforce the TFH fate remain poorly defined. This limits our ability to dissect the altered biology underlying lupus. Additionally, the study of human TFH has been hampered by lack of access to the secondary lymphoid tissues where they differentiate and function. Changes in the epigenetic code mediate the identity, specificity, stability, and function of differentiated CD4+ T helper (Th) cell subsets. Indeed, the epigenetic landscape may be a better indicator of the developmental and functional relationships amongst Th subsets than lineage-specific transcription factors. In preliminary data, our epigenetic analyses show that a significant number of lupus susceptibility GWAS SNPs map to regions of open chromatin in TFH, suggesting that altered TFH biology mediates a significant component of lupus genetic risk. We previously used unique murine models to define discreet stages of TFH differentiation: conventional DCs prime CD4+ T cells toward an unstable pre-TFH intermediate that expresses Bcl6 and CXCR5. Cognate T-B interactions drive the pre-TFH to produce IL-21, express PD-1, and repress production of IL-17. Preliminary epigenetic analyses confirm that pre-TFH are not fully committed to the TFH fate and show that we can identify a B cell-dependent module. However, B cell MHCII expression--with no requirement for DC priming--is sufficient for TFH differentiation in immunological settings similar to lupus. The proposal will utilize unique murine models and primary human cells to establish the epigenetic roadmap that defines commitment to the TFH fate. Lupus-prone mice with limited expression of MHCII will be utilized to define how sequential interactions between CD4+ T cells and DCs followed by B cells mediate changes in the epigenetic code. ATAC-Seq analyses of pre-TFH and TFH will identify the regulatory cascades, transcription factor programs, and metabolic pathways that are regulated by DCs and B cells during TFH differentiation. Secondly, we will build on these analyses to define how lupus disrupts this transcriptional and functional program. Does lupus: 1. alter the requirement for sequential cDC and B cell antigen presentation in the differentiation and maintenance of TFH? or 2. disrupt the epigenetic landscape of TFH differentiation and commitment? These experiments should identify the epigenetic signatures that 1. Define the B cell contribution to TFH differentiation and 2. Distinguish TFH in lupus and health controls. These results will provide the framework for future therapeutic interventions to ameliorate disease.

抽象的 狼疮中存在的抗核自身抗体 (ANA) 是高亲和力、类别转换的抗体，产生于 T 细胞依赖性生发中心 (GC) 反应。 GC 的发展和持久性依赖于以下方面的帮助 滤泡辅助 CD4+ T 细胞 (TFH)。尽管 TFH 的异常发育和功能会导致两种疾病 SLE 患者和狼疮小鼠模型，启动和强化狼疮的分子和细胞途径 TFH 的命运仍然不明确。这限制了我们剖析狼疮背后改变的生物学的能力。 此外，人类 TFH 的研究因无法接触次级淋巴组织而受到阻碍 它们在哪里区分和发挥作用。表观遗传密码的变化介导身份、特异性、稳定性、 和分化的 CD4+ T 辅助 (Th) 细胞亚群的功能。事实上，表观遗传景观可能是一个 比谱系特异性更好地指示 Th 亚群之间的发育和功能关系 转录因子。在初步数据中，我们的表观遗传学分析表明，大量狼疮患者 易感性 GWAS SNP 映射到 TFH 开放染色质区域，表明 TFH 生物学发生改变 介导狼疮遗传风险的一个重要组成部分。 我们之前使用独特的小鼠模型来定义 TFH 分化的谨慎阶段：传统 DC 将 CD4+ T 细胞引向表达 Bcl6 和 CXCR5 的不稳定前 TFH 中间体。同源 T-B 相互作用驱动 pre-TFH 产生 IL-21、表达 PD-1 并抑制 IL-17 的产生。初步的 表观遗传学分析证实 TFH 前并不完全受 TFH 命运影响，并表明我们可以识别 B 细胞依赖性模块。然而，B 细胞 MHCII 表达（无需 DC 启动）就足够了 用于类似于狼疮的免疫环境中的 TFH 分化。 该提案将利用独特的小鼠模型和原代人类细胞来建立表观遗传路线图 这定义了对 TFH 命运的承诺。 MHCII 表达有限的狼疮易感小鼠将被用于 定义 CD4+ T 细胞和 DC 以及 B 细胞之间的顺序相互作用如何介导 表观遗传密码。前 TFH 和 TFH 的 ATAC-Seq 分析将鉴定调控级联、转录 TFH 分化过程中 DC 和 B 细胞调节的因子程序和代谢途径。 其次，我们将在这些分析的基础上确定狼疮如何破坏这种转录和功能。 程序。狼疮是否： 1. 改变 cDC 和 B 细胞抗原呈递顺序的要求 TFH的分化和维持？或 2. 破坏 TFH 分化的表观遗传景观， 承诺？这些实验应确定表观遗传特征： 1. 定义 B 细胞的贡献 2. 区分狼疮和健康对照中的 TFH。这些结果将提供 未来改善疾病的治疗干预框架。