Epigenetics of the autoantibody response in systemic lupus

系统性狼疮自身抗体反应的表观遗传学

基本信息

批准号：
10494251
负责人：
Paolo Casali
金额：
$ 71.08万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-24 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10494251
关键词：
ATAC-seq Ablation Address Affinity Antibodies Antibody Response Ascorbic Acid Attention Autoantibodies Autoimmune Diseases Autoimmunity B cell differentiation B-Cell Activation B-Lymphocytes Bacteria Binding Butyrates Cell physiology Cells ChIP-seq Chemosensitization Cues DNA DNA analysis Data Development Down-Regulation Elements Enhancers Epigenetic Process Estrogens Female Fumarates Gene Expression Genes Genetic Genetic Predisposition to Disease Genetic Recombination Genetic Transcription Histone Deacetylase Histones Homologous Gene Hormonal Human IgG autoantibodies Immunize Immunoglobulin Class Switching Immunoglobulin G Immunoglobulin Somatic Hypermutation Immunoglobulins Impairment In Vitro Inbred MRL lpr Mice Knock-in Knock-in Mouse Left Ligands Link Lupus Mediating Mediator of activation protein Memory Metabolic Molecular Mus Mutate Nutritional PRDM1 gene Patients Phosphorylation Plasma Plasma Cells Pristane Prodrugs Proteins Regulation Rest Role SIRT1 gene Stimulus Systemic Lupus Erythematosus Systems Biology T-Lymphocyte TNFSF5 gene Testing Therapeutic Transcript Untranslated RNA Up-Regulation Viral Virus Vitamin A Vitamins activation-induced cytidine deaminase alpha ketoglutarate analog bisulfite cytokine demethylation epigenetic regulation experience experimental study genomic locus glycosylation inhibitor innovation mouse model mutant neutralizing antibody novel organ injury pathogenic autoantibodies plasma cell differentiation programs recruit response small molecule therapeutic target tissue injury tool transcription factor

项目摘要

PROJECT SUMMARY/ABSTRACT. Epigenetics of the autoantibody response in systemic lupus. Like “mature” antibody responses to viruses and bacteria, the lupus autoantibody response requires B cell class- switch DNA recombination (CSR), somatic hypermutation (SHM) and plasma cell differentiation. As we have shown, epigenetic factors, including histone modifiers (such as Sirt1) and inhibitors (such as butyrate) modulate B cell expression of AID (gene: AICDA/Aicda) and Blimp-1 (PRDM1/Prdm1), which are critically for CSR/SHM and plasma cell differentiation, respectively. Towards a better definition of the epigenetic landscape of lupus B cells, we hypothesize that Tet2, a key epigenetic factor, mediates the lupus autoantibody response, as prompted the B cell-intrinsic role of Tet2 in CSR/SHM and plasma cell differentiation (our recent findings). We argue that Tet2 is induced by the stimuli that induce B cell CSR/SHM and plasma cell differentiation, and it is upregulated in lupus B cells. We also argue that Tet2 boosts transcription of Aicda and Prdm1 through its Fe2+ and a- ketoglutarate (a-KG)-dependent catalytic activity for DNA demethylation as well as its non-catalytic function, i.e., recruiting Ogt (encoded by X-linked OGT/Ogt) to these loci to effect histone glycosylation. Finally, we contend that B cell Tet2 transduces hormonal, nutritional and metabolic cues into epigenetic changes to modulate autoantibody responses, as Tet2 transcription could be upregulated by estrogen (E2, our preliminary data) and vitamin A, and Tet2 is activated by vitamin C, but inhibited by fumarate (a metabolite and a-KG competitor) – as shown by us, E2 boosts AID expression, which would enhance females’ antibody and autoantibody responses. With extensive experience in and commitment to the mechanistic understanding of human and mouse lupus autoantibody responses, we are uniquely poised to test our hypotheses using molecular B cell biology systems, cutting-edge epigenetic tools (hydroxylmethyl DNA analysis, bisulfite and oxidative bisulfite conversion, ChIP and ATAC-Seq), genetically modified mice (TgAicda-creTet2fl/fl, Tet2HxD-mut/HxD-mut and Tet2Ogt-mut/Ogt-mut knockin mice, TgAicda-creOgtfl/fl, Tet2HxD-mut/HxD-mutTgAicda-creOgtfl/fl, MRL/Lpr TgAicda-creTet2fl/fl, MRL/Lpr Tet2HxD-mut/HxD-mut and MRL/Lpr TgAicda-creOgtfl/fl), proprietary humanized H-Mice® and Lupus-H-Mice® models. Aim 1 addresses human and mouse B cell differentiation stage-specific (resting, activated, plasma and memory cell) regulation of Tet2, Tet2 protein stability, E2 upregulation of Tet2 transcripts and underlying mechanisms. Aim 2 addresses the B cell- intrinsic role of Tet2 in promoting AID and Blimp-1 expression, the underlying mechanisms (active DNA demethylation and Ogt-mediated histone glycosylation), and potentiation effect of Tet2 inducer vitamin A and activator vitamin C, and suppressive effect of Tet2 catalytic inhibitor (fumarate, TET-IN-C35 or Bobcat339) alone or combined with Ogt ablation or Tet2Ogt-mut/Ogt-mut knockin. Aim 3 analyzes dysregulation of Tet2 and Tet2- mediated epigenetic mechanisms in human and mouse lupus B cells, addresses the role of Tet2 in lupus, and explores Tet2 inhibitors and Ogt inhibitor ST045849 as lupus therapeutics. Our experiments will unveil novel and targetable epigenetic mechanisms that integrate environmental cues to inform the lupus autoantibody response.

项目摘要/摘要。全身性狼疮中自身抗体反应的表观遗传学。像对病毒和细菌的“成熟”抗体反应，狼疮自身抗体反应需要B细胞类别开关DNA重组（CSR），体细胞超数（SHM）和浆细胞分化。正如我们所拥有的显示的表观遗传因素，包括组蛋白修饰剂（例如SIRT1）和抑制剂（例如丁酸酯）调节 B细胞的AID（基因：AICDA/AICDA）和Blimp-1（PRDM1/PRDM1）的B细胞表达，对CSR/SHM至关重要和浆细胞分化。为了更好地定义狼疮B的表观遗传景观细胞，我们假设TET2是一种关键的表观遗传因子，介导了狼疮自身抗体反应，如提示 TET2在CSR/SHM和浆细胞分化（我们最近的发现）中的B细胞中性作用。我们争论 TET2是由影响B细胞CSR/SHM和浆细胞分化的刺激引起的，并且已更新在狼疮B细胞中。我们还认为TET2启动AICDA和PRDM1通过其Fe2+和A-的转录 Ketoglutarate（A-KG）依赖性催化活性，用于DNA脱甲基及其非催化功能，即募集OGT（由X连锁的OGT/OGT编码）到这些地方以实现组蛋白糖基化。最后，我们联系了 B细胞TET2将荷尔蒙，营养和代谢线索转化为表观遗传变化以调节自身抗体反应，因为TET2转录可以通过雌激素（E2，我们的初步数据）和维生素A和TET2被维生素C激活，但被富马酸盐（代谢物和A-KG竞争者）抑制 - 如由我们展示，E2增强了辅助表达，这将增强女性的抗体和自身抗体反应。具有丰富的经验和对人和老鼠狼疮的机械理解的承诺自身抗体反应，我们被中毒以使用分子B细胞生物学系统检验我们的假设，尖端的表观遗传工具（羟基甲基DNA分析，亚硫酸盐和氧化亚硫酸盐转化，芯片和ATAC-SEQ），基因修饰的小鼠（tgaicda-cretet2fl/fl，tet2hxd-mut/hxd-mut和tet2ogt-mut/ogt-mut敲击小鼠， tgaicda-creogtfl/fl，tet2hxd-mut/hxd-muttgaicda-creogtfl/fl，mrl/lpr tgaicda-cretet2fl/fl/fl，mrl/lpr tet2hxd-mut/hxd-mut/hxd-mut和mrl/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr/lpr TGAICDA-CREOGTFL/FL），专有的人源化H-Mice®和狼疮-H-Mice®型号。目标1解决了人类和小鼠B细胞分化阶段特异性（静止，激活，等离子体和记忆细胞）的调节TET2，TET2 蛋白质稳定性，TET2转录本和潜在机制的E2上调。 AIM 2解决B细胞 - TET2在促进辅助和Blimp-1表达中的固有作用，即潜在机制（活动DNA 脱甲基化和OGT介导的组蛋白糖基化）以及TET2诱导者维生素A和活化剂维生素C和TET2催化抑制剂的抑制作用（富马酸酯，TET-IN-C35或BOBCAT339）或与OGT消融或TET2OGT-MUT/OGT-MUT敲门蛋白结合使用。 AIM 3分析TET2和TET2-的失调人和小鼠狼疮细胞中介导的表观遗传机制，解决了TET2在狼疮中的作用，以及探索TET2抑制剂和OGT抑制剂ST045849作为狼疮疗法。我们的实验将推出小说，综合环境线索的目标表观遗传机制为狼疮自身抗体反应提供了信息。