Epigenetic mechanisms in Transgenerational Effects of an Environmental Pollutant

环境污染物跨代效应的表观遗传机制

• 批准号: 10440259
• 负责人: Mitzi Nagarkatti
• 金额: $ 48.48万
• 依托单位: UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-24 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10440259
• 关键词: ATAC-seq; Adult; Affect; Anti-Inflammatory Agents; Antigens; Aryl Hydrocarbon Receptor; Azacitidine; Bacterial Infections; Biological Assay; Biosensor; CD4 Positive T Lymphocytes; Cell Differentiation process; Cells; Centers for Disease Control and Prevention (U.S.); Cessation of life; Chromatin; Complex; DNA; DNA Methylation; DNA Modification Methylases; Data; Developing Countries; Development; Dioxins; Down-Regulation; Endocrine Disruptors; Environmental Pollutants; Environmental Pollution; Environmental Risk Factor; Enzymes; Epigenetic Process; Exposure to; FOXP3 gene; Female; Fertilization; GATA3 gene; Gene Expression; Generations; Genes; Genomic Imprinting; Genomics; Histones; IL17 gene; Immune response; Infection; Inflammation; Inflammatory; Interferon Type II; Interleukin-10; Interleukin-17; Interleukin-4; Lead; Life; Ligands; Maternal Exposure; Mediating; Methylation; Methyltransferase; MicroRNAs; Modality; Modeling; Morbidity - disease rate; Mothers; Mus; Neonatal; Newborn Infant; Parents; Partner in relationship; Paternal Exposure; Pathway interactions; Peripheral; Phase; Phenotype; Play; Pregnancy; Preventive; Receptor Activation; Regulatory T-Lymphocyte; Resistance; Role; S-Adenosylhomocysteine; Site; Staphylococcal Enterotoxin B; Staphylococcus aureus; Superantigens; System; T cell clonality; T cell differentiation; T cell response; T-Cell Receptor; T-Lymphocyte; T-cell diversity; T-cell receptor repertoire; Testing; Tetrachlorodibenzodioxin; Th1 Cells; Therapeutic; Time; Toxic Shock Syndrome; Toxic effect; Transfection; Transforming Growth Factor beta; Up-Regulation; aryl hydrocarbon receptor ligand; base; chromatin remodeling; complementarity-determining region 3; cytokine; cytokine release syndrome; demethylation; differential expression; endocrine disruptor exposure; epigenome; genome-wide; histone methylation; histone modification; immunoregulation; immunotoxicity; imprint; inhibitor; innovation; insight; male; mortality; novel; overexpression; pregnant; promoter; reproductive; response; restriction enzyme; transcription factor; transmission process

Abstract Bacterial infections during neonatal phase cause high rates of morbidity and mortality, and in developing countries are responsible for 26% of deaths. Environmental factors present during pregnancy are known to impact life-threatening infections in newborns, including Staph. aureus infections, although the mechanisms are unclear. Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental pollutant, which acts through the cytosolic aryl hydrocarbon receptor (AhR). While AhR has been well characterized for its role in regulating toxicity mediated by TCDD, recently, AhR activation was shown to regulate T cell differentiation into T regs or Th17 cells. We have generated exciting preliminary data indicating that AhR activation by TCDD suppresses T cell response to Staphylococcal enterotoxin B (SEB) and that this is mediated by epigenetic pathways including dysregulation in microRNA (miR) expression, DNA methylation, and histone modifications in activated T cells. More importantly, our studies have suggested that TCDD may exert transgenerational epigenetic effects on T cells. Based on the importance of Staph infections discussed above, we will use SEB as an antigen to test the central hypothesis that AhR activation of Vβ8+ T cells by TCDD, plays a crucial role in reducing pro-inflammatory Th1/Th17 cells as well as increasing anti-inflammatory Tregs and its subsets by modulating miR expression, and that this may depend on DNA methylation, histone modifications and chromatin remodeling that could be transmitted transgenerationally. Inasmuch as, SEB can activate Vβ8+ T cells which constitute ~30% of peripheral T cells, our studies are aimed at determining whether TCDD-induced changes persist in F0, F1, F2, and F3 generations following maternal exposure during pregnancy to TCDD or maternal/paternal exposure prior to mating (F0). In Aim 1, we will determine the transgenerational effects of TCDD on SEB-induced CD4+ T cell differentiation. We will test the effect of TCDD on the TCR clonality and diversity of the Vβ8+ CD4+ T cell response (Th1, 2, 17, Tregs) to SEB. In Aim 2, we will study the role of specific miRs in CD4+ T cell differentiation in F0-F3 generations. Furthermore, transfection of T cells with specific miR mimics or antagomirs will be performed to reverse T cell differentiation induced by TCDD and determine whether the effects persist across generations. In Aim 3, we will determine the role of genome-wide and locus-specific DNA methylation on CpG sites on promoters of specific miR that regulate differential expression of Th/Treg response to SEB across the generations. Aim 4 will elucidate the permissive and repressive histone modification and chromatin accessibility in TCDD-mediated transgenerational dysregulation of miR involved in CD4+ T cell differentiation. Lastly, whether these changes are imprinted through male or female germline will be assessed. The proposed studies are highly significant in that novel epigenetic pathways of TCDD-mediated immunotoxicity across generations will be identified. Also, understanding how AhR ligands mediate differential effects through epigenetic pathways would lead to development of innovative preventive and therapeutic modalities.

抽象的 新生儿阶段的细菌感染导致高发病率和死亡率，并且在发育中 26% 的死亡由国家造成。众所周知，怀孕期间存在的环境因素 影响新生儿的危及生命的感染，包括葡萄球菌。金黄色葡萄球菌感染，尽管其机制是 不清楚。四氯二苯并-对-二恶英 (TCDD) 是一种环境污染物，通过细胞质作用 芳烃受体（AhR）。 AhR 因其在调节毒性方面的作用而得到了充分的表征 在 TCDD 介导下，最近，AhR 激活被证明可以调节 T 细胞分化为 T reg 或 Th17 细胞。我们已经生成了令人兴奋的初步数据，表明 TCDD 激活 AhR 会抑制 T 细胞 对葡萄球菌肠毒素 B (SEB) 的反应，这是由表观遗传途径介导的，包括 活化 T 细胞中 microRNA (miR) 表达、DNA 甲基化和组蛋白修饰的失调。 更重要的是，我们的研究表明TCDD可能对T产生跨代表观遗传效应。 细胞。基于上面讨论的葡萄球菌感染的重要性，我们将使用 SEB 作为抗原 检验中心假设，即 TCDD 对 Vβ8+ T 细胞的 AhR 激活在减少 促炎性 Th1/Th17 细胞以及增加抗炎性 Tregs 及其亚群 调节 miR 表达，这可能取决于 DNA 甲基化、组蛋白修饰和 染色质重塑可以跨代遗传。因为SEB可以激活Vβ8+ T 细胞约占外周 T 细胞的 30%，我们的研究旨在确定 TCDD 是否诱导 母亲在怀孕期间接触 TCDD 后，F0、F1、F2 和 F3 代的变化持续存在 交配前母体/父体暴露（F0）。在目标 1 中，我们将确定跨代效应 TCDD 对 SEB 诱导的 CD4+ T 细胞分化的影响。我们将测试TCDD对TCR克隆性的影响以及 Vβ8+ CD4+ T 细胞（Th1、2、17、Tregs）对 SEB 反应的多样性。在目标 2 中，我们将研究具体的作用 F0-F3 代 CD4+ T 细胞分化中的 miR。此外，用特定的miR转染T细胞 将进行模拟或antagomir来逆转TCDD诱导的T细胞分化，并确定是否 这种影响会持续几代人。在目标 3 中，我们将确定全基因组和位点特异性的作用 调节 Th/Treg 差异表达的特定 miR 启动子上 CpG 位点的 DNA 甲基化 几代人对 SEB 的响应。目标 4 将阐明组蛋白的许可性和抑制性修饰 TCDD 介导的 CD4+ T 细胞 miR 跨代失调中的染色质可及性和染色质可及性 差异化。最后，将评估这些变化是否通过男性或女性种系印记。 拟议的研究对于 TCDD 介导的免疫毒性的新表观遗传途径具有非常重要的意义 跨代将被识别。此外，了解 AhR 配体如何通过 表观遗传途径将导致创新预防和治疗方式的发展。