Genetic and epigenetic contributions to the neonatal Th2 bias

遗传和表观遗传对新生儿 Th2 偏向的贡献

• 批准号: 8650789
• 负责人: REBECCA D ADKINS
• 金额: $ 19.19万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-10 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8650789
• 关键词: Adult; Allergic Disease; Allogeneic Lymphocyte; Anti-Inflammatory Agents; Anti-inflammatory; Asthma; Birth; CD4 Positive T Lymphocytes; Catalytic Domain; Cell Lineage; Cells; Childhood; Chromatin; Coupled; Cytokine Gene; DNA; DNA Methyltransferase; DNA Modification Methylases; DNA-Binding Proteins; Data; Development; Developmental Biology; Disease; Effector Cell; Elements; Employee Strikes; Enhancers; Epigenetic Process; Exposure to; Foundations; Functional RNA; Future; Gene Expression; Genes; Genetic; Genome; Genome Components; Goals; Growth; Health; Immune response; Immune system; Immunity; In Vitro; Infection; Interleukin-13; Interleukin-4; Intervention; Knowledge; Lead; Learning; Life; Link; Mediating; Memory; Methylation; Methyltransferase; Modification; Molecular; Monitor; Mus; Neonatal; Newborn Animals; Nucleic Acid Regulatory Sequences; Pattern; Play; Predisposition; Prevention approach; Production; Proteins; Regulation; Regulatory Element; Resistance; Role; Staging; T-Lymphocyte; Techniques; Testing; Th2 Cells; Transgenic Mice; Vaccination; Vaccines; Work; Zinc Fingers; base; cytokine; demethylation; design; fetal; genetic element; genetic manipulation; improved; in vivo; juvenile animal; meetings; microorganism; neonate; novel; novel strategies; prevent; public health relevance; research study; response

DESCRIPTION (provided by applicant): Immune responses in neonates are often defined by dominant production of anti-inflammatory Th2 cytokines, a condition referred to as the neonatal Th2 bias. This pattern of cytokine secretion is thought to contribute to the susceptibility of young animals to infection and to the development of Th2-mediated diseases, such as asthma. Thus, vigorous Th2 function is a key defining feature of immunity in early life. Learning how this arises is of central importance for our understanding of the ontogeny of the adaptive immune system. The Th2 biased responses of neonates are due, in part, to rapid, high-level Th2 cytokine production. We have demonstrated that the Th2 cytokines IL-4 and IL-13 are both produced early and in copious amounts by newly activated murine neonatal CD4+ cells. In adult Th2 cells, coordinate expression of high levels of Th2 cytokines requires an intergenic regulatory region called conserved non-coding region 1 (CNS-1). Therefore, the CNS-1 genetic element may contribute importantly to the early, robust Th2 cytokine production in neonates. Indeed, this DNA element exists in a relatively permissive epigenetic state in early ontogeny. We have found that, unlike in naive adult cells, CNS-1 is hypomethylated at CpG residues in naive fetal and neonatal T lineage cells. This hypomethylated state is strongly linked to rapid, high level Th2 cytokine production by neonatal CD4+ cells. Methylation of CNS-1 occurs rapidly post birth, with adult levels of methylation being attained by the end of the first week o life. Increasing methylation of CNS-1 with increasing development is associated with the progressive silencing of rapid Th2 cytokine gene expression. Together, these observations indicate that CNS-1 may play a centrally important role in defining the neonatal Th2 bias. Our long-term goals are to understand the genetic and epigenetic contributions to the Th2 dominant state of early life. In this proposal, we will focus on the well-defined CNS-1 region in the Th2 cytokine locus. Our preliminary data lead to two clear hypotheses. Specific Aim 1 will test the idea that the physical presence of the CNS-1 region is required to achieve Th2 cytokine overproduction in neonates. This will be achieved by comparing the epigenetic state of the Th2 locus and Th2 cytokine production in wild-type and CNS-1-deficient neonates. Specific Aim 2 will examine the premise that hypomethylation of CNS-1 in fetal and neonatal life is essential for generating the neonatal Th2 bias. This will be tested by creating transgenic mice with forced methylation of CNS-1 throughout development. Constructs containing a CNS-1-targeted zinc finger protein coupled to the catalytic domain of the de novo DNA methyltransferase Dnmt3a will be created~ expression of the constructs will be confined to T lineage cells. The epigenetic state of the Th2 locus and Th2 function will be assessed in the transgenic mice. These studies will be the first to dissect genetic and epigenetic regulation at the Th2 cytokine locus in early ontogeny. Results from these studies will ultimately lead to interventional strategies aimed at improving pediatric health by mitigating the Th2 dominant state in early life.

描述（由申请人提供）：新生儿中的免疫反应通常由抗炎Th2细胞因子的主要产生来定义，这种疾病称为新生儿Th2偏置。 人们认为这种细胞因子分泌的模式有助于幼小动物感染和Th2介导的疾病（例如哮喘）的敏感性。 因此，剧烈的Th2功能是早期免疫力的关键定义特征。 了解这是如何理解适应性免疫系统的个体发育至关重要的。 新生儿的Th2偏见反应部分归因于快速，高级Th2细胞因子的产生。 我们已经证明，Th2细胞因子IL-4和IL-13都是由新激活的鼠新生儿CD4+细胞以早期和大量生产的。 在成年Th2细胞中，高水平Th2细胞因子的坐标需要一个称为保守的非编码区域1（CNS-1）的基因间调节区域。 因此，CNS-1遗传元件可能对新生儿的早期，强大的Th2细胞因子产生重要贡献。 实际上，该DNA元件在早期发育中存在相对允许的表观遗传状态。 我们发现，与幼稚的成年细胞不同，CNS-1在幼稚胎儿和新生儿T谱系细胞中的CpG残基上被甲基化。 该次甲基化态与新生儿CD4+细胞的快速，高水平的Th2细胞因子产生密切相关。 CNS-1的甲基化发生后出生后迅速发生，成人甲基化水平在第一周O生命结束之前获得。 随着发育的增加，CNS-1的甲基化增加与快速Th2细胞因子基因表达的逐步沉默有关。 总之，这些观察结果表明，CNS-1在定义新生儿Th2偏置方面可能发挥着重要的作用。 我们的长期目标是了解对早期Th2主要状态的遗传和表观遗传学贡献。 在此提案中，我们将重点关注Th2细胞因子基因座定义明确的CNS-1区域。 我们的初步数据导致两个明确的假设。 具体目标1将测试CNS-1区域的物理存在以实现新生儿中Th2细胞因子过量产生的想法。 这将通过比较野生型和CNS-1缺陷型新生儿中Th2基因座和Th2细胞因子产生的表观遗传状态来实现。 具体目标2将研究以下前提：胎儿和新生儿生活中CNS-1的甲基化对于产生新生儿Th2偏见至关重要。 这将通过用强制创建转基因小鼠来测试 整个开发过程中CNS-1的甲基化。 将创建包含CNS-1靶向的锌指蛋白与从头DNA甲基转移酶DNMT3A的催化结构域耦合的构造〜构建体的表达将局限于T谱系细胞。 表观遗传学 TH2基因座和Th2功能的状态将在转基因小鼠中进行评估。 这些研究将是第一个在早期发育中剖析Th2细胞因子基因座的遗传和表观遗传调节的研究。 这些研究的结果最终将导致介入策略，旨在通过减轻早期的Th2优势状态来改善小儿健康。