ANALYSIS OF INOSITOL PHOSPHATE METABOLISM IN T LYMPHOCYTES BY HPLC

HPLC分析磷酸肌醇在T淋巴细胞中的代谢

• 批准号: 3811108
• 负责人: E BONVINI
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3811108
• 关键词: T cell receptor; T lymphocyte; antigen presentation; biological signal transduction; calcium metabolism; cyclic AMP; cyclic GMP; high performance liquid chromatography; human tissue; laboratory mouse; leukocyte activation /transformation; leukocyte adhesion molecules; lipid metabolism; phosphatidylinositols; phospholipase C; tissue /cell culture

To determine the type of metabolites, the time of generation and the metabolic pathways of transformation of the inositol phosphates (InsP) produced upon T lymphocyte activation. An early event associated with T cell receptor (TCR) / antigen (Ag) interaction is the activation of an inositol phospholipid (InsPL)-specific phospholipase C (PLC), with consequent hydrolysis of membrane phospholipids. This metabolic pathway produces a series of InsP, which may be involved in cell activation by mobilizing Ca(+2) from either endogenous or extracellular compartments. A consistent amount of evidence indicates that Ins(1,4,5)P3 metabolism may play a crucial role in the regulation of Ca(+2) metabolism. Ins(1,4,5)P3 is directly involved in Ca(+2) mobilization from intracellular stores. Studies performed in platelets and brain tissues demonstrated that Ins(1,4,5)P3 may be hydrolyzed to Ins(1,4)P2 by a specific 5-phosphomonoesterase (5PME) or phosphorylated by a 3-kinase (3K) to Ins(1,3,4,5)P4. Ins(1,4)P2 appears be deprived of biological activity, while Ins(1,3,4,5)P4 may act as a Ca(+2) mobilizer by opening certain sensitive membrane channels. The higher phosphorylated InsP5 and InsP6 may also have biological significance, perhaps acting as intercellular mediators. The present project proposes to investigate the regulation of Ins(1,4,5)P3 metabolism in human and murine T-lymphocytes in response to perturbation of the TCR. Conditions whereby different activation pathways may also be simultaneously triggered will be given special attention. This refers in particular to T cell activation by Ag in the presence of Ag-presenting, "accessory" cells with the consequent interaction with "accessory" and/or adhesion molecules. Activation of other signal transduction mechanisms, such as cAMP or cGMP by proper ligands (i.e.: prostaglandins) will also be considered regarding their effect on the generation of the InsP isomers.

为了确定代谢物的类型、生成时间和 肌醇磷酸（InsP）转化的代谢途径 产生于T淋巴细胞活化。与T相关的早期事件 细胞受体（TCR）/抗原（Ag）相互作用是一种免疫应答的激活。 肌醇磷脂（InsPL）特异性磷脂酶C（PLC）， 随后膜磷脂发生水解。这种代谢途径 产生一系列InsP，这可能涉及细胞活化， 从内源性或细胞外区室中动员Ca（+2）。一 大量证据表明，Ins（1，4，5）P3代谢可能 在Ca（+2）代谢的调节中起着至关重要的作用。Ins（1，4，5）P3是 直接参与Ca（+2）从细胞内储存的动员。研究 在血小板和脑组织中进行的研究表明，Ins（1，4，5）P3可能 通过特异性5-磷酸单酯酶（5PME）水解为Ins（1，4）P2，或 通过3-激酶（3K）磷酸化为Ins（1，3，4，5）P4。Ins（1，4）P2似乎是 而Ins（1，3，4，5）P4可能作为Ca（+2）的配体， 动员剂通过打开某些敏感的膜通道。越高 磷酸化的InsP5和InsP6也可能具有生物学意义， 可能充当细胞间介质。本项目建议 研究人和小鼠Ins（1，4，5）P3代谢的调控 T淋巴细胞对TCR扰动的响应。的条件下 也可以同时触发不同的激活途径 给予特别关注。这特别是指T细胞活化， 在存在Ag呈递的情况下，"辅助"细胞与随之而来的 与"辅助"和/或粘附分子相互作用。激活其他 信号转导机制，如cAMP或cGMP通过适当的配体 (i.e.:也将考虑它们对 InsP异构体的产生。