NFAT in naive, effector and memory Th1 and Th2 cells

幼稚细胞、效应细胞和记忆 Th1 和 Th2 细胞中的 NFAT

• 批准号: 6334881
• 负责人: Mercedes Rincon
• 金额: $ 20.14万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6334881
• 关键词: AP1 protein; CD4 molecule; T cell receptor; apoptosis; cell population study; developmental immunology; genetic transcription; genetically modified animals; helper T lymphocyte; immunologic memory; laboratory mouse; leukocyte activation /transformation; lymphocyte proliferation; transcription factor

The balance of naive, effector Th1 and Th2 and memory CD4+ T cells is critical for the course of an immune response. Differences in cytokine production, activation signal requirement, surface maker expression and life span characterize these stages of CD4+ T cells, but little is known about the molecular mechanisms that determine these phenotype characteristics. This project represents an effort to define the regulation and the role of the transcription factor NFAT in the differentiation and activation of naive, effector and memory CD4+ T cells. Our previous studies have demonstrated that the regulation of the activity of specific transcription factors depends on the differentiation stage of cells. We have shown that AP-1 and NFAT can mediate transcription in effector Th2 cells, but not in Th1 cells. AP-1- and NFAT-mediated transcription requires T cell receptor (TcR) and co-stimulatory signals in naive CD4+ T cells, while only TcR-mediated signals are required in effector Th2 cells. The presence of JunB in AP-1 complexes appears to be relevant for the specific regulation of AP-1 transcriptional activity in Th2 cells. In this project we propose to extend these studies to determine how NFAT transcriptional activity is regulated during the development of memory cells for naive and effector CD4+ cells, specifically gene expression, DNA binding, and nuclear translocation of the different NFAT family members (Aim 1). Our preliminary data suggest that the relative ratio of two components of the NFAT family, NFAT1 and NFAT2, varies during the differentiation of CD4+ T cells and that can be one regulatory factor of NFAT-mediated transcription. We will determine whether changes in the NFAT1/NFAT2 ratio influence the expression of cytokine of activation/death molecule gene in vitro, by overexpressing NFAT2 in CD4+ T cell clones (Aim 2). To determine the physiological relevance of NFAT1/NFAT2 ratio on the generation, activation and survival of naive, effector and memory CD4+ T cells in vivo, we will overexpress NFAT2 selectively in T cells in an inducible manner using transgenic mice (Aim 3). We believe that these studies will provide new insights about the importance of NFAT in the control of effector and memory immune responses.

幼稚的、效应性的Th1和Th2细胞以及记忆性的CD4+T细胞的平衡对免疫反应的过程至关重要。细胞因子的产生、激活信号的需求、表面标志物的表达和寿命的不同是这些阶段的特征，但关于决定这些表型特征的分子机制还知之甚少。这个项目是为了确定转录因子NFAT在初始、效应和记忆CD4+T细胞的分化和激活中的调节和作用。我们以前的研究表明，特定转录因子活性的调节依赖于细胞的分化阶段。我们已经证明，AP-1和NFAT可以介导效应Th2细胞的转录，但不能介导Th1细胞的转录。AP-1和NFAT介导的转录需要T细胞受体(TCR)和初始的CD4+T细胞的共刺激信号，而效应Th2细胞只需要TCR介导的信号。AP-1复合体中JunB的存在似乎与Th2细胞中AP-1转录活性的特异性调节有关。在这个项目中，我们建议扩展这些研究，以确定NFAT转录活性在幼稚和效应CD4+细胞的记忆细胞发育过程中是如何调节的，特别是不同NFAT家族成员的基因表达、DNA结合和核转位(目标1)。我们的初步数据表明，NFAT家族的两个组分NFAT1和NFAT2的相对比例在CD4+T细胞分化过程中发生变化，这可能是NFAT介导的转录调控因素之一。我们将通过在CD4+T细胞克隆中过表达NFAT2来确定NFAT1/NFAT2比例的变化是否会在体外影响激活/死亡分子基因的细胞因子的表达(目标2)。为了确定NFAT1/NFAT2比例与体内幼稚、效应和记忆性CD4+T细胞的生成、激活和存活的生理学相关性，我们将使用转基因小鼠以诱导的方式选择性地在T细胞中过度表达NFAT2(目标3)。我们相信，这些研究将为NFAT在控制效应器和记忆免疫反应中的重要性提供新的见解。