Role of micro-RNAs in T cells and other immune/haematopoietic cells

摘要：微RNA （miRNAs）是一种短的、约21个核苷酸（nt）的RNA分子，在多种真核生物中通过影响信使RNA （mRNA）的稳定性来调节基因表达。miRNA通路在进化上是高度保守的，单个miRNA已被证明在细胞分化、增殖、凋亡、细胞谱系规范和癌症中发挥重要作用。我们之前已经在选定的小鼠造血细胞类别中记录了不同的miRNA表达模式，其中包括幼稚T细胞及其后代Thl和Th2细胞。我们还表明，缺乏RNase样酶Dicer（在细胞质中执行miRNA加工的最后一步）的T细胞表现出Th1偏倚；相反，缺乏siRNA/ miRNA外切酶mExo的T细胞优先分化为Th2细胞。本提案描述了这些研究的延伸，其中选定的mirna在免疫和造血系统中的功能将被系统地研究，目标mrna产生的基因产物的作用将被研究。在目标1中。我们将探讨miR-146及其靶点TRAF6在T细胞分化中的作用，重点是我们最近发现的转录因子NFAT是一种TRAF6相互作用蛋白，它几乎影响T细胞功能的各个方面。miRNAs 146、221/222和223在T细胞/造血细胞分化中的功能将被研究，主要是通过在胚胎干细胞和小鼠中靶向破坏。在目标3。通过无偏克隆、深度测序和微阵列转录谱分析，鉴定在Th1/Th2分化中具有潜在作用的新mirna及其可能的靶mrna。总之，这些研究应该大大增加我们对mirna在T细胞和其他免疫和造血系统细胞中的作用的理解。

DESCRIPTION (provided by applicant): Title: Role of micro-RNAs in T cells and other immune/ hematopoietic cells Abstract MicroRNAs (miRNAs) are short, ~21 nucleotide (nt) RNA molecules that modulate gene expression by influencing messenger RNA (mRNA) stability in a variety of eukaryotic organisms. The miRNA pathway is evolutionarily very highly conserved, and individual miRNAs have been demonstrated to play important roles in cell differentiation, proliferation, apoptosis, cell lineage specification and cancer. We have previously documented distinct miRNA expression patterns in selected classes of murine hematopoietic cells, among them naive T cells and their progeny Thl and Th2 cells. We have also shown that T cells lacking the RNase -like enzyme Dicer, which performs the last step of miRNA processing in the cytoplasm, exhibit a Th1 bias; and that conversely, T cells lacking the siRNA/ miRNA exonuclease mExo preferentially differentiate into Th2 cells. This proposal describes an extension of these studies, in which the functions of selected miRNas in the immune and hematopoietic systems will be systematically investigated, and the role of gene products produced by target mRNAs will be investigated. In Aim 1. the role of miR-146 and its target TRAF6 in T cell differentiation will be explored, focusing on our recent finding that the transcription factor NFAT, which influences almost every aspect of T cell function, is a TRAF6-interacting protein In Aim 2. the functions of miRNAs 146, 221/222 and 223 in T cell/ hematopoietic cell differentiation will be investigated, primarily through targeted disruption in ES cells and in mice. In Aim 3. new miRNAs with potential roles in Th1/Th2 differentiation and their possible target mRNAs will be identified through unbiased cloning, deep sequencing and transcriptional profiling by microarray analysis. Together these studies should greatly increase our understanding of the role of miRNAs in T cells and other cells of the immune and hematopoietic systems.