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。系统性狼疮自身抗体反应的表观遗传学。与对病毒和细菌的“成熟”抗体反应一样，狼疮自身抗体反应需要 B 细胞类别- 开关DNA重组（CSR）、体细胞超突变（SHM）和浆细胞分化。结果表明，表观遗传因素，包括组蛋白修饰剂（如 Sirt1）和抑制剂（如丁酸盐）可调节 B 细胞表达 AID（基因：AICDA/Aicda）和 Blimp-1（PRDM1/Prdm1），这对于 CSR/SHM 至关重要和浆细胞分化，分别更好地定义狼疮 B 的表观遗传景观。细胞中，我们追寻 Tet2（一种关键的表观遗传因子）介导狼疮自身抗体反应，如提示的 Tet2 在 CSR/SHM 和浆细胞分化中的 B 细胞内在作用（我们最近的发现）。 Tet2 受诱导 B 细胞 CSR/SHM 和浆细胞分化的刺激诱导，并且上调我们还认为 Tet2 通过其 Fe2+ 和 a- 增强 Aicda 和 Prdm1 的转录。 DNA 去甲基化的酮戊二酸 (a-KG) 依赖性催化活性及其非催化功能，即将 Ogt（由 X 连锁 OGT/Ogt 编码）招募到这些位点以实现组蛋白糖基化。 B 细胞 Tet2 将激素、营养和代谢信号转导为表观遗传变化以进行调节自身抗体反应，因为雌激素可以上调 Tet2 转录（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 – 如我们发现，E2 可以增强 AID 的表达，从而增强女性的抗体和自身抗体反应。拥有丰富的经验并致力于人类和小鼠狼疮的机制理解自身抗体反应，我们独特地准备使用分子 B 细胞生物学系统来测试我们的假设，尖端的表观遗传学工具（羟甲基 DNA 分析、亚硫酸氢盐和氧化亚硫酸氢盐转化、ChIP 和 ATAC-Seq）、转基因小鼠（TgAicda-creTet2fl/fl、Tet2HxD-mut/HxD-mut 和 Tet2Ogt-mut/Ogt-mut 敲入小鼠， TgAicda-creOgtfl/fl、Tet2HxD-mut/HxD-mutTgAicda-creOgtfl/fl、MRL/Lpr TgAicda-creTet2fl/fl、MRL/Lpr Tet2HxD-mut/HxD-mut 和 MRL/Lpr TgAicda-creOgtfl/fl)，专有的人性化 H-Mice® 和 Lupus-H-Mice® Aim 1 针对人类和小鼠。小鼠 B 细胞分化阶段特异性（静息细胞、激活细胞、浆细胞和记忆细胞）Tet2 的调节，Tet2 蛋白质稳定性、Tet2 转录本的 E2 上调和潜在机制 Tet2在促进AID和Blimp-1表达中的内在作用，其潜在机制（活性DNA 去甲基化和 Ogt 介导的组蛋白糖基化），以及 Tet2 诱导剂维生素 A 和的增强作用激活剂维生素 C，以及单独使用 Tet2 催化抑制剂（富马酸盐、TET-IN-C35 或 Bobcat339）的抑制作用或与 Ogt 消融或 Tet2Ogt-mut/Ogt-mut 敲入组合，目的 3 组合 Tet2 和 Tet2- 的失调。介导人类和小鼠狼疮 B 细胞的表观遗传机制，解决 Tet2 在狼疮中的作用，以及探索 Tet2 抑制剂和 Ogt 抑制剂 ST045849 作为狼疮治疗方法，我们的实验将揭示新颖且可靠的方法。整合环境线索以告知狼疮自身抗体反应的可靶向表观遗传机制。