SIGNAL TRANSDUCTION PATHWAYS IN THE TH2 SUBSET

TH2 子集中的信号转导途径

• 批准号: 6340708
• 负责人: AMNON ALTMAN
• 金额: $ 12.57万
• 依托单位: LA JOLLA INSTITUTE FOR IMMUNOLOGY
• 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 2001-10-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6340708
• 关键词: CD38 molecule; T cell receptor; biological signal transduction; calcium flux; cell differentiation; cooperative study; enzyme mechanism; genetically modified animals; guanine nucleotide binding protein; helper T lymphocyte; hypersensitivity; immunopharmacology; laboratory mouse; leukocyte activation /transformation; mitogen activated protein kinase; phospholipase C; protein kinase; sphingosine

The importance of Th1 and Th2 cells in the normal physiology and pathology of the immune system is well established. Th2-derived cytokines play a central role in the pathophysiology of allergy and asthma. Past studies have documented differences in T cell receptor (TCR)-initiated early signaling between Th1 and Th2 cells. To date, however, no Th2-specific signaling pathways have been identified. The unerlying working hypothesis is that unique TCR-proximal signaling pathways exist in Th2 cells, and that such molecular events represent potential drug targets for selectively interfering with Th2 function. This project will focus on a detailed comparative analysis of early signaling events in Th2 vs. Th1 cells with emphasis on antigen-dependent activation systems. We will: 1) Assess early signaling events during Th2 cell activation and the effects of pharmacological inhibitors/stimulators on the differentiation of naive CD4+ T cells using established clones and T cells from TCR-transgenic mice. These studies will be combined with the use of pharmacological agents which modulate defined T cell signaling events. Effects of these drugs on naive T cell differentiation into Th1 or Th2 cells will be analyzed. 2) Analyze the role of protein tyrosine kinases (PTKs) of the Src. Syk and Tec families in Th1 vs. Th2 cells, and the effects of transient/stable overexpression of wild type or catalytically inactive kinases on activation of the two subsets will be analyzed. 3) Determine the Molecular basis of Ca2+ signaling in Th2 cells, Ca2+ signals in Th2 cells have been reported to differ quantitatively and/or qualitatively from those in Th1 cells. Studies will address the potential role of three alternative Ca2+ signaling pathways mediated by: a) Gq-coupled phospholipase Cbeta: b) sphingosine kinase; or c) CD38. The latter two enzymes generate novel Ca2+-mobilizing second messengers, sphingosine-1-phosphate and cADP ribose, respectively. 4) Analyze the roles of the Ras and MAP kinase signaling pathways in Th2 cells. The function of these pathways (which are critical for Th1 activation) in Th2 cells has not been addressed. We will measure activation of Ras and its downstream Ser/Thr kinases and transcriptional activators, examine the effects of dominant-negative Ras, and assess the role of stress-activated protein kinases in Th2 activation. The information generated by this project is critical for our ability to rationally devise pharmacological treatments designed to selectively inhibit Th2 activation and, thus, interfere with allergic responses.

Th1和Th2细胞在正常生理学和 免疫系统的病理已经建立。 Th2衍生 细胞因子在过敏的病理生理学中起着核心作用 和哮喘。 过去的研究记录了T细胞的差异 受体（TCR）在Th1和Th2之间引起的早期信号传导 细胞。 但是，迄今为止，没有Th2特异性信号通路 已经确定了。 无效的工作假设是 Th2细胞中存在独特的TCR-羟化信号通路，并且 这样的分子事件代表了潜在的药物靶标 有选择地干扰TH2功能。 这个项目将 专注于早期信号的详细比较分析 Th2与Th1细胞中的事件，重点依赖抗原 激活系统。 我们将：1）评估早期信号事件 在Th2细胞激活期间和药理学的影响 对幼稚CD4+ T分化的抑制剂/刺激剂 使用TCR-转基因的已建立克隆和T细胞的细胞 老鼠。 这些研究将与使用 调节定义T细胞信号传导的药理剂 事件。 这些药物对幼稚T细胞分化的影响 将分析进入Th1或Th2细胞。 2）分析 SRC的蛋白酪氨酸激酶（PTK）。 SYK和TEC家庭 在Th1与Th2细胞中，瞬态/稳定的影响 野生型或催化性激酶的过表达 将分析两个子集的激活。 3）确定 Th2细胞中Ca2+信号的Ca2+信号的分子基础Ca2+信号 据报道，在Th2细胞中有差异和/或 定性来自Th1细胞中的细胞。 研究将解决 三个替代Ca2+信号通路的潜在作用 介导：A）GQ耦合的磷脂酶CBETA：B） 鞘氨醇激酶；或C）CD38。 后两个酶产生 新型Ca2+ - 动力第二信使，鞘氨醇1-磷酸盐 和CADP核糖。 4）分析RAS的作用 并在Th2细胞中绘制激酶信号通路。 功能 这些途径（对于TH1激活至关重要） 细胞尚未解决。 我们将测量RAS的激活 及其下游Ser/Thr激酶和转录 激活剂，检查主要阴性RA的效果，以及 评估应激激活蛋白激酶在TH2中的作用 激活。 该项目产生的信息是 对于我们合理设计药理学的能力至关重要 旨在选择性抑制Th2激活的治疗和 因此，干扰过敏反应。