ION CHANNELS AND SIGNALING MECHANISMS IN T LYMPHOCYTES

T 淋巴细胞中的离子通道和信号传导机制

• 批准号: 2444775
• 负责人: RICHARD S LEWIS
• 金额: $ 31.37万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2444775
• 关键词: T cell receptor; T lymphocyte; antifungal antibiotics; calcium channel; calcium flux; chemical kinetics; confocal scanning microscopy; flow cytometry; gene induction /repression; immunopharmacology; leukocyte activation /transformation; mitochondria; plant insecticide; protein kinase; reporter genes; ruthenium; tissue /cell culture; transcription factor; voltage /patch clamp

DESCRIPTION (Adapted from the investigator's application): The elevation of intracellular free calcium concentration by antigen plays a pivotal role in determining the fate and functions of T lymphocytes. The long term goals of this proposal are to elucidate the mechanisms that generate and regulate the calcium signal, and to understand how it activates specific T-cell activation genes. Work over the past five years indicates that Ca2+ signaling in T cells is sustained by capacitative Ca2+ entry, a widespread signaling mechanism by which the depletion of intracellular Ca2+ stores activated Ca2+ entry through Ca2+ release-activated Ca2+ (CRAC) channels. Relatively little is known about how these channels are regulated and how their activity determines responses such as T-cell activation or tolerance. Four specifics aims are proposed to elucidate the regulation and functions of CRAC channels in T cells using a combination of microscopic imaging and patch-clamp techniques: 1) Determine the dependence of CRAC channel activation on store content and intracellular Ca2+. 2) Investigate the mechanism by which intracellular Ca2+ feeds back to slowly inactivate CRAC channels. 3) Establish the role of mitochondria in modulating the Ca2+ signal and test the hypothesis that they influence CRAC channel function by interfering with slow inactivation. 4) Examine the role of [Ca2+]i oscillations in increasing the efficiency and/or the specificity of transcriptional responses, using reporter genes driven by two Ca2+-sensitive transcriptions factors, NFAT and AP-1. The significance of these studies is that they will describe for the first time several cellular processes that control the dynamic behavior of depletion-activated Ca2+ channels. Moreover, in many cells the specific consequences of dynamic Ca2+ signals such as oscillations has been largely unexplored, and these studies will assess their impact on a definable and physiologically important end point, gene activation. Given the requirement for CRAC channel function in T-cell activation, these studies may ultimately expose a number of control points for the immune response, leading to new strategies for immunomodulation with important therapeutic benefit in the prevention or treatment of disorders such as AIDS and autoimmune disease.

描述（改编自研究者的申请）： 抗原引起的细胞内游离钙浓度起着关键作用 决定T淋巴细胞的命运和功能。 的长期目标 该提案旨在阐明产生和调节 钙信号，并了解它如何激活特定 T 细胞 激活基因。 过去五年的工作表明 Ca2+ T 细胞中的信号传导是通过电容性 Ca2+ 进入来维持的，这是一种广泛存在的现象。 细胞内 Ca2+ 储存耗尽的信号机制 通过 Ca2+ 释放激活 Ca2+ (CRAC) 通道激活 Ca2+ 进入。 对于如何监管​​这些渠道以及如何进行监管，人们知之甚少。 它们的活性决定了 T 细胞激活或耐受等反应。 提出四个具体目标来阐明监管和职能 结合显微成像和 T 细胞中的 CRAC 通道 膜片钳技术：1）确定CRAC通道的依赖性 储存内容和细胞内 Ca2+ 的激活。 2）调查 细胞内Ca2+反馈缓慢失活CRAC的机制 渠道。 3) 确定线粒体在调节Ca2+中的作用 信号并测试它们影响 CRAC 通道功能的假设 干扰缓慢失活。 4) 检查[Ca2+]i的作用 提高效率和/或特异性的振荡 转录反应，使用由两个 Ca2+ 敏感驱动的报告基因 转录因子 NFAT 和 AP-1。 这些研究的意义在于它们将首次描述 对控制动态行为的几个细胞过程进行计时 耗尽激活的 Ca2+ 通道。 此外，在许多细胞中，特定的 动态 Ca2+ 信号（例如振荡）的后果已在很大程度上 未经探索，这些研究将评估它们对可定义和 生理上重要的终点，基因激活。 鉴于要求 对于 CRAC 通道在 T 细胞激活中的功能，这些研究最终可能 暴露许多免疫反应的控制点，从而产生新的 具有重要治疗效果的免疫调节策略 预防或治疗艾滋病和自身免疫性疾病等疾病。