MECHANISMS OF NATURAL KILLER CELL ACTIVATION

自然杀伤细胞激活机制

• 批准号: 2092722
• 负责人: PAUL J LEIBSON
• 金额: $ 18.54万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-03-12 至 1997-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2092722
• 关键词: G protein; antibody receptor; biological signal transduction; cell mediated lymphocytolysis test; clone cells; exocytosis; flow cytometry; granule; human tissue; interleukin 2; leukocyte activation /transformation; natural killer cells; phospholipase C; protein tyrosine kinase; protooncogene; receptor coupling; tissue /cell culture

A crucial event in the development of NK cell-mediated cytotoxicity is the receptor-stimulated secretion of granule-derived proteins. Prior to NK cell activation, pre-formed granules containing an array of cytotoxic and proteolytic molecules gather beneath the cell surface. With NK cell receptor recognition of susceptible targets, intracellular biochemical signals are generated that direct the final transport of the granules to the inner surface of the plasma membrane and the subsequent exocytotic fusion events. The long-term goals of this project are to define the relationship between specific signal transduction pathways and the regulation of granule exocytosis. For this proposal, experimental systems have been developed in which intact or permeabilized preparations of cloned NK cells can be used for the direct manipulation and evaluation of the relevant pathways. Preliminary work suggests that the transmembrane signaling events involve not only the selective activation of specific phospholipase C (PLC) isoforms, but other second messengers (e.g. protein tyrosine kinases, G proteins) also critically regulate the secretory response. The hypotheses formulated from these preliminary observations are tested in the following specific aims: 1) Characterize PLC-gamma activation in NK cells and its role in receptor-stimulated granule exocytosis; 2) Evaluate protein tyrosine-kinase-dependent, but PLC-independent transmembrane signals that also regulate NK cell secretion; 3) Analyze the role of G protein-mediated signals in the downstream propagation of signals leading to exocytosis; and 4) Evaluate the effects of IL-2 and the proto-oncogene p56(lck) on the secretory response. Together these studies will provide an experimental basis for understanding the molecular events that are involved in the regulation of NK cell secretion, and will, in a broader context, advance our understanding of fundamental processes involved in transmembrane signaling and lymphocyte activation.

NK 细胞介导的细胞毒性发展中的一个关键事件是 受体刺激颗粒衍生蛋白的分泌。 之前 NK 细胞活化，含有一系列细胞毒性物质的预成型颗粒 蛋白水解分子聚集在细胞表面下方。 含NK细胞 敏感靶标的受体识别、细胞内生化 产生的信号指导颗粒的最终运输 质膜的内表面和随后的胞吐 融合事件。 该项目的长期目标是定义 特定信号转导途径与相关性的关系 颗粒胞吐作用的调节。 对于这个提案，实验性的 已开发出完整或透化制剂的系统 克隆的 NK 细胞可用于直接操作和评估 的相关途径。 初步工作表明 跨膜信号传导事件不仅涉及选择性激活 特定磷脂酶 C (PLC) 亚型，但其他第二信使 （例如蛋白酪氨酸激酶、G蛋白）也关键性地调节 分泌反应。 根据这些初步提出的假设 观察结果按照以下具体目标进行测试：1）表征 NK 细胞中的 PLC-gamma 激活及其在受体刺激中的作用 颗粒胞吐作用； 2) 评估蛋白酪氨酸激酶依赖性，但是 不依赖 PLC 的跨膜信号也可调节 NK 细胞 分泌; 3）分析G蛋白介导的信号在 导致胞吐作用的信号下游传播； 4) 评估 IL-2和原癌基因p56(lck)对分泌的影响 回复。 这些研究共同将为 了解参与调节的分子事件 NK 细胞的分泌，并将在更广泛的背景下推进我们的研究 了解跨膜的基本过程 信号传导和淋巴细胞激活。