ACTIVATION DEFECTS IN AGING T CELLS

衰老 T 细胞的激活缺陷

• 批准号: 2051092
• 负责人: RICHARD A MILLER
• 金额: $ 24.14万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1995-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2051092
• 关键词: T lymphocyte; aging; antibody; biological signal transduction; calcium channel; calcium flux; flow cytometry; gel electrophoresis; gene expression; genetic manipulation; laboratory mouse; laboratory rabbit; laboratory rat; leukocyte activation /transformation; leukocyte activation disorder; membrane potentials; mitogens; oncogenes; phosphoproteins; phosphorylation; protein kinase; tissue /cell culture

We propose a series of studies of T lymphocyte activation in old and young mice aimed at identifying in biochemical terms of defect(s) that prevent many T cells from old mice from responding to mitogens. We have previously shown age-related derangements in the generation of cytoplasmic calcium signals in T cells from old donors, and now propose to test two explanatory hypotheses: (a) that aged T cells have over-active calcium extrusion systems; and (b) that the low resting membrane potential of T cells from old mice interferes with calcium signal degeneration. Our studies of early signal transduction have hinted that pathways dependent on protein kinase C may be less impaired by aging than other kinase- dependent paths; we now propose more direct and systematic tests of protein kinase function and substrate specificity in T cells from old mice. We have previously documented age-related defects in Con A-induced expression of c-myc mRNA. We now propose to test for age-related changes in expression of selected cell cycle related genes (c-fos, c-jun IL-2, and IL-2R) in responses to mitogenic stimuli (Con A, anti-CD3). Nonmitogenic activators (PMA, ionomycin) will be used in studies of gene expression and protein kinase function to identify pathways to particularly susceptible to age-related dysfunction. Antibodies to c-myc and c-fos proteins will be used to look for altered gene expression at the single cell level and in T cell subsets thought to be particularly susceptible to senescent change. Finally we propose to look for evidence of age-related defects in splicing of primary RNA transcripts, defects that we have previously suggested may be responsible for age-related loss of myc mRNA accumulation. We hope to identify specific age-related defects in calcium signals, protein kinase function, and gene expression that might contribute to poor T lymphocyte function in old mice.

我们提出了一系列关于老年人和年轻人T淋巴细胞活化的研究 旨在从生化方面识别缺陷的小鼠(S) 许多老年小鼠的T细胞对有丝分裂原有反应。我们有 以前显示的与年龄相关的细胞质产生的紊乱 来自老年捐赠者的T细胞中的钙信号，现在建议测试两个 解释性假设：(A)衰老的T细胞钙过度活跃 挤出系统；和(B)T的低静息膜电位 老年小鼠的细胞会干扰钙信号的退化。我们的 对早期信号转导的研究表明，依赖于 蛋白激酶C在衰老过程中的受损程度可能比其他蛋白激酶- 依赖路径；我们现在建议更直接和系统地测试 老年人T细胞的蛋白激酶功能及其底物特异性 老鼠。我们以前曾记录过Con A诱导的与年龄相关的缺陷 C-myc基因的表达。我们现在建议测试与年龄相关的变化 在选定的细胞周期相关基因(c-fos、c-jun IL-2和 IL-2R)对有丝分裂刺激的反应(ConA，抗CD3)。无丝分裂原 激活剂(PMA、离子霉素)将用于基因表达和 蛋白激酶功能识别特别易感的途径 与年龄相关的功能障碍。C-myc和c-fos蛋白抗体将 用于在单细胞水平上寻找改变的基因表达 在被认为特别容易衰老的T细胞亚群中 变化。最后，我们建议寻找年龄相关缺陷的证据 初级RNA转录本的剪接，我们以前有过的缺陷 提示可能是与年龄相关的myc基因缺失的原因 积累。我们希望找出特定的与年龄相关的钙缺陷。 信号、蛋白激酶功能和可能的基因表达 导致老年小鼠T淋巴细胞功能低下。