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）：新生儿的免疫反应通常由抗炎Th 2细胞因子的主导产生来定义，这种情况称为新生儿Th 2偏好。 这种细胞因子分泌模式被认为有助于年轻动物对感染的易感性和Th 2介导的疾病如哮喘的发展。 因此，强有力的Th 2功能是生命早期免疫的关键定义特征。 了解这是如何发生的是至关重要的，我们了解适应性免疫系统的个体发育。 新生儿的Th 2偏向反应部分是由于快速、高水平的Th 2细胞因子产生。 我们已经证明，Th 2细胞因子IL-4和IL-13都产生早期和大量的新激活的小鼠新生儿CD 4+细胞。 在成年Th 2细胞中，高水平Th 2细胞因子的协调表达需要称为保守非编码区1（CNS-1）的基因间调节区。 因此，CNS-1遗传元件可能对新生儿早期、稳健的Th 2细胞因子产生有重要贡献。 事实上，这种DNA元件在个体发育早期以相对宽松的表观遗传状态存在。 我们已经发现，与幼稚成人细胞不同，CNS-1在幼稚胎儿和新生儿T谱系细胞中的CpG残基处低甲基化。 这种低甲基化状态与新生儿CD 4+细胞快速、高水平的Th 2细胞因子产生密切相关。 CNS-1的甲基化在出生后迅速发生，在生命的第一周结束时达到成人甲基化水平。 随着发育的增加，CNS-1甲基化的增加与快速Th 2细胞因子基因表达的进行性沉默有关。 总之，这些观察结果表明，CNS-1可能在定义新生儿Th 2偏倚中发挥重要作用。 我们的长期目标是了解遗传和表观遗传对早期生命Th 2优势状态的贡献。 在这个建议中，我们将集中在明确的CNS-1区域的Th 2细胞因子基因座。 我们的初步数据导致两个明确的假设。 具体目标1将测试这样的想法，即CNS-1区域的物理存在是实现新生儿中Th 2细胞因子过度产生所必需的。 这将通过比较野生型和CNS-1缺陷型新生儿中Th 2基因座和Th 2细胞因子产生的表观遗传状态来实现。 具体目标2将检查的前提下，低甲基化的CNS-1在胎儿和新生儿的生活是必不可少的产生新生儿Th 2的偏见。 这将通过创造转基因小鼠进行测试， CNS-1在整个发育过程中的甲基化。 将创建包含与从头DNA甲基转移酶Dnmt 3a的催化结构域偶联的CNS-1靶向锌指蛋白的构建体~构建体的表达将仅限于T谱系细胞。 表观遗传 在转基因小鼠中评估Th 2基因座的状态和Th 2功能。 这些研究将是第一个解剖的遗传和表观遗传调控在Th 2细胞因子基因座在早期个体发育。 这些研究的结果将最终导致旨在通过减轻生命早期Th 2优势状态来改善儿科健康的干预策略。