Intrinsic B cell epigenetic regulation of antibody and autoantibody responses by Sirt1

Sirt1 对抗体和自身抗体反应的内在 B 细胞表观遗传调控

• 批准号: 10335163
• 负责人: Paolo Casali
• 金额: $ 47.44万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-14 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10335163
• 关键词: 3' Untranslated Regions; ATAC-seq; Address; Aftercare; Aging; Allergens; Animal Model; Antibodies; Antibody Response; Antigens; Autoantibodies; Autoantigens; Autoimmune Diseases; Autoimmunity; B cell differentiation; B-Cell Activation; B-Lymphocytes; Back; Bacteria; Biochemistry; Biosensor; Cell physiology; Cellular biology; ChIP-seq; Cues; DNA Methylation; DNA Modification Methylases; Data; Deacetylation; Dependence; Development; Diabetes Mellitus; Dietary Fiber; Down-Regulation; Elements; Epigenetic Process; Gene Activation; Gene Expression; Genes; Genetic; Genetic Predisposition to Disease; Genetic Recombination; Genetic Transcription; Genome; Glucose; Goals; Grant; Histone Deacetylase; Histone Deacetylase Inhibitor; Histone Deacetylation; Histone H3; Histones; Homeostasis; Human; IgG autoantibodies; Image; Immunoglobulin Class Switching; Immunoglobulin Somatic Hypermutation; Immunoglobulins; In Vitro; Inbred MRL lpr Mice; Internal Ribosome Entry Site; Luciferases; Lupus; MYB gene; Malignant Neoplasms; Mediating; Mediator of activation protein; Memory; Memory B-Lymphocyte; Metabolic; MicroRNAs; Modification; Molecular; Mouse Strains; Mus; Mutate; NF-kappa B; Patients; Phase; Plasma Cells; Post-Translational Protein Processing; Pristane; Process; Regulation; Reporter; Rest; Role; SIRT1 gene; SLEB1 gene; Signal Pathway; Sirtuins; Supplementation; Testing; Therapeutic; Transcription Coactivator; Transcription Repressor; USF1 gene; Untranslated RNA; Up-Regulation; Virus; Volatile Fatty Acids; Water; activation-induced cytidine deaminase; animal imaging; cell type; cofactor; demethylation; ds-DNA; epigenetic regulation; experimental study; gut microbiota; human model; humanized mouse; immunoregulation; in vivo; innovation; insight; nicotinamide-beta-riboside; non-histone protein; novel; novel therapeutics; organ injury; overexpression; programs; promoter; response; sensor; small molecule; stem; systemic autoimmunity; therapeutic target; tissue injury; tool; transcriptome sequencing

PROJECT SUMMARY We want to unveil novel fundamental B cell-intrinsic epigenetic mechanisms that maintain B cell homeostasis and inform B cell processes critical to the antibody response to exogenous antigens (e.g., viruses, bacteria) and self-antigens (e.g., dsDNA, RNPs in systemic lupus). As we have shown in the first cycle of this grant, epigenetic mechanisms interact with genetic programs to modulate AID (encoded by AICDA/Aicda) expression, critical for SHM/CSR. Indeed, Zn2+-dependent Class I, II and IV HDACs promote AID induction and SHM/CSR in a B cell-intrinsic fashion. AID induction is dampened by Class I, II and IV HDAC inhibitors, such as short- chain fatty acids produced by gut microbiota via processing of dietary fibers, through upregulation of select microRNAs that target AICDA/Aicda 3’UTR, leading to abrogation of antibody/autoantibody responses. Prompted by our most recent and compelling findings on Sirt1, a NAD+-dependent Class III HDAC and metabolic sensor implicated in aging, cancer and diabetes, we hypothesize that this Sirtuin dampens AID (a role opposite to that of Class I, II and IV HDACs) in a B cell-intrinsic fashion, and regulation of Sirt1 expression or activity effectively modulates SHM/CSR and antibody/autoantibody responses. As we contend, high Sirt1 levels/activity would effect homeostatic Aicda silencing in resting B cells, the first phase of a tri-phasic fluctuation of reciprocal Sirt1 and AID expression, as followed by low Sirt1 and high AID in activated B cells and back to high Sirt1 to low AID in plasma cells and memory B cells. Sirt1 would modulate AID expression through a three-prong histone and non-histone protein deacetylation. It would also enforce a B cell-intrinsic metabolic–epigenetic checkpoint of AID upregulation since Sirt1 cofactor NAD+ integrates metabolic cues. Our strengths in B cell biology, molecular SHM/CSR mechanisms and autoimmunity, as well as our cutting- edge epigenetic approaches (ChIP-Seq, methylDNA-Seq and ATAC-Seq), new tools in biochemistry (NAD+ biosensor), genetics (Cd19+/Cre-Ert2Sirt16fl/flRosa26fl-STOP-fl-tdTomato and Cd19+/Cre-Ert2Rosa26fl-STOP-fl-Sirt1-IRES-Gfp mice), imaging (AicdaCreRosa26fl-STOP-fl-luciferase reporter mice), and animal models of human antibody/autoantibody responses (humanized NSG/cKitW-41J mice) make us uniquely poised to test our hypotheses. Aim1 addresses human and mouse B cell differentiation stage-specific regulation of Sirt1 expression and NAD+ levels, and underlying mechanisms, with focus on transcription activator USF1, transcription repressor c-Myb and microRNAs targeting Sirt1 3’UTR. Aim 2 addresses B cell Sirt1 role in dampening AICDA/Aicda expression through genetics and/or compounds/metabolites, and defines underlying H3K4Ac, H3K36Ac, Dnmt1 and NF- kB deacetylation mechanisms; Aim 3 addresses the inhibition of antibody and autoantibody responses by B cell Sirt1 and Sirt1 activators, and explores Sirt1 activators as therapeutics in systemic lupus. Our highly significant and innovative experiments will provide novel mechanistic insights into B cell epigenetics and immunoregulation, and yield metabolic-epigenetic checkpoint modulators as new therapeutics in autoimmunity.!

项目摘要 我们希望揭示新的基本B细胞内在的表观遗传机制，维持B细胞的稳态 并告知对外源抗原的抗体应答至关重要的B细胞过程（例如，病毒、细菌） 和自身抗原（例如，dsDNA，系统性狼疮中的RNP）。正如我们在第一轮赠款中所显示的那样， 表观遗传机制与遗传程序相互作用以调节AID（由AICDA/Aicda编码）表达， 对SHM/CSR至关重要。事实上，Zn 2+依赖性I、II和IV类HDAC促进AID诱导和SHM/CSR 以B细胞固有的方式。AID诱导被I类、II类和IV类HDAC抑制剂抑制，例如短- 肠道微生物群通过加工膳食纤维产生的链脂肪酸， 靶向AICDA/Aicda 3 'UTR的微小RNA，导致抗体/自身抗体应答的消除。 我们最近对Sirt 1的最新和令人信服的发现证实了这一点，Sirt 1是一种NAD+依赖的III类HDAC， 我们假设这种Sirtuin抑制了AID（一种与衰老、癌症和糖尿病有关的代谢传感器）， 与I、II和IV类HDAC的作用相反）以B细胞内在的方式，以及Sirt 1表达的调节 或活性有效地调节SHM/CSR和抗体/自身抗体应答。正如我们所说，高Sirt 1 水平/活性将影响静息B细胞中的稳态Aicda沉默，这是三阶段Aicda沉默的第一阶段。 Sirt 1和AID表达的相互波动，随后在活化的B细胞中出现低Sirt 1和高AID 浆细胞和记忆B细胞中的Sirt 1升高，AID降低。Sirt 1可调节AID的表达 通过组蛋白和非组蛋白的三重脱乙酰化。它也会强制执行一个B细胞-内在的 由于Sirt 1辅因子NAD+整合了代谢线索，因此AID上调的代谢表观遗传检查点。 我们在B细胞生物学、分子SHM/CSR机制和自身免疫方面的优势，以及我们的切割- 边缘表观遗传学方法（ChIP-Seq，methylDNA-Seq和ATAC-Seq），生物化学新工具（NAD+ 生物传感器），遗传学（Cd 19 +/Cre-Ert 2Sirt 16 fl/flRosa 26 fl-STOP-fl-td Tomato和Cd 19 +/Cre-Ert 2 Rosa 26 fl-STOP-fl-Sirt 1-IRES-GFP小鼠）， 成像（AicdaCreRosa 26 fl-STOP-fl-荧光素酶报告小鼠）和人抗体/自身抗体的动物模型 这些反应（人源化NSG/cKitW-41 J小鼠）使我们独特地准备好测试我们的假设。Aim 1地址 人和小鼠B细胞分化阶段特异性调节Sirt 1表达和NAD+水平，和 潜在的机制，重点是转录激活因子USF 1，转录抑制因子c-Myb和 靶向Sirt 1 3 'UTR的microRNA。目的2阐明B细胞Sirt 1在抑制AICDA/Aicda表达中的作用 通过遗传学和/或化合物/代谢物，并定义了潜在的H3 K4 Ac，H3 K36 Ac，Dnmt 1和NF-κ B。 kB脱乙酰化机制;目的3阐述了B对抗体和自身抗体应答的抑制 细胞Sirt 1和Sirt 1激活剂，并探讨Sirt 1激活剂作为系统性狼疮的治疗。我们高度 重要的和创新的实验将提供新的机制见解B细胞表观遗传学和 免疫调节，并产生代谢表观遗传检查点调节剂作为自身免疫的新疗法。