Role of miRNAs in Th2-Driven inflammation in Asthma

描述(申请人提供)：哮喘是一种慢性呼吸道疾病，以呼吸道过敏性炎症为特征。辅助性T细胞2型(Th2)通过分泌细胞因子来协调和放大变态反应性炎症。拟议的研究解决了中心假设，即辅助T细胞表达的microRNAs(MiRNAs)调节导致哮喘病理的细胞功能。MiRNAs是内源性表达的~21nt调控基因表达的RNAs。众所周知，不能形成任何成熟miRNAs的T细胞在增殖、存活、细胞因子产生和分化为Th1和Th2效应亚群方面存在缺陷。剩下的挑战是确定调节每个过程的特定miRNAs，确定它们与哮喘中T细胞功能的相关性，并确定这些miRNAs介导其作用的信使RNA靶标。在具体目标1中，我们将应用最近开发的工具将miRNA模拟物和抑制剂输送到原代小鼠和人类T细胞中，进行功能筛选，以识别调节与哮喘相关的辅助T细胞功能的miRNAs。AIM 2中提出的实验将利用一种新的方法，在限制起始RNA数量的情况下，在高度特征化的哮喘患者亚组的临床样本中发现哮喘相关T细胞miRNA的表达模式，并将这些模式与疾病的临床特征和Th2相关的分子表型联系起来。在目标3中，我们将利用基因组学和详细的分子分析以及哮喘小鼠模型来表征选定的miRNAs的mRNA靶点和体内功能。这些研究将首先集中在初步功能筛选和表达谱中确定的3个强有力的候选miRNAs。

DESCRIPTION (provided by applicant): Asthma is a chronic respiratory condition characterized by allergic inflammation of the airways. T helper type 2 (Th2) cells coordinate and amplify allergic inflammation through the secretion of cytokines. The proposed studies address the central hypothesis that microRNAs (miRNAs) expressed by helper T cells regulate cellular functions that contribute to asthma pathology. miRNAs are endogenously expressed ~21nt RNAs that regulate gene expression. It is known that T cells that cannot form any mature miRNAs exhibit defects in proliferation, survival, cytokine production, and differentiation into Th1 and Th2 effector subsets. The challenges that remain are to identify the particular miRNAs that regulate each of these processes, to define their relevance to T cell functions in asthma, and to determine the messenger RNA targets through which these miRNAs mediate their effects. In Specific Aim 1, we will apply recently developed tools for delivering miRNA mimics and inhibitors into primary mouse and human T cells to perform functional screens that will identify miRNAs that regulate helper T cell functions relevant to asthma. The experiments proposed in Aim 2 will utilize a novel approach for miRNA expression profiling in limiting quantities of starting RNA to discover asthma-associated T cell miRNA expression patterns in clinical samples from highly characterized asthma patient subgroups, and to relate those patterns to clinical features and Th2-associated molecular phenotypes of disease. In Aim 3, we will characterize the mRNA targets and in vivo function of select miRNAs using genomics and detailed molecular analyses as well as mouse models of asthma. These studies will focus first on 3 strong candidate miRNAs identified in preliminary functional screens and expression profiling.