CYTOKINE GENE EXPRESSION BY CD4+ CELLS IN AGING MICE

该项目的长期目标是：i)了解 对细胞因子基因表达的限制--从而限制细胞 功能--在健康人的CD4+T细胞群中，以及 二)在老年人的CD4+T细胞隔间内确定 个人，可能导致以下现象的改变 免疫衰老。在此建议使用鼠标系统来 人类CD4+T细胞表型和功能异质性模型。 流式细胞荧光技术将用于分析脾中的CD4+ 取自幼年、中年和老年小鼠的细胞 3G11、CD45RB和CD44三种细胞表面决定簇的表达 用限制性模式划分CD4+细胞亚群的想法 细胞因子的产生和细胞功能。随后，CD4+细胞， 从各个年龄段的小鼠中分离出来的，将被刺激 抗CD3epsilon单抗的体外鉴定：I) 细胞周期进入和进展的程度和II)模式 几种T细胞相关细胞因子的产生，在 稳定的信使核糖核酸积累或蛋白质分泌水平。在……里面 此外，来自幼年Thy-1同种异型小鼠和来自 适当背景品系的老年小鼠将被用于细胞 混合实验研究CD_4~+-CD_4~+细胞年龄相关性变化 通讯。为了关联3G11、CD45RB和 CD44表达具有CD4+细胞功能，将分离出细胞亚群 基于这些标记的表达水平，然后评估 刺激依赖的细胞周期进程与细胞因子的模式 基因表达。比较分析将在以下两种情况下进行 年轻组内的不同子集和子集匹配 各年龄段之间的准备工作。最后，细胞混合实验。 上述描述将被扩展以包括子集-子集的评估 幼年小鼠的CD4+细胞之间的通讯，以及潜在的 随着老鼠年龄的增长，这些交流的变化。结果 从这些研究中应该进一步加深我们对功能 健康个体的CD4+细胞室的异质性，以及 老龄化对老年人的代表性和能力的影响 CD4+细胞亚群。

The long-term goals of this project are: i) to understand the spatial restrictions on cytokine gene expression - and, consequently, on cell function - within the CD4+T cell population of healthy individuals, and ii) to identify, within, the CD4+ T cell compartment of elderly individuals, alterations which may underlie the phenomenon of immunosenescence. It is proposed herein to use the mouse system to model phenotypic and functional heterogeneity among human CD4+ T cells. Flow cytofluorometric techniques will be used to analyze splenic CD4+ cells from young adult, middle-aged, and old mice for the simultaneous expression of three cell surface determinants - 3G11, CD45RB, and CD44 - thought to demarcate CD4+ cell subsets with restricted patterns of cytokine production and cell function. Subsequently, CD4+ cells, isolated from mice of each age group, will be stimulated with anti-CD3epsilon monoclonal antibody in vitro and then evaluated for: i) extent of cell cycle entry and progression and ii) patterns of production of several T cell-associated cytokines, monitored at the level of either steady-state mRNA accumulation or protein secretion. In addition, CD4+ cells from young Thy-1 allotype congenic mice and from old mice of the appropriate background strain will be used in cell mixing experiments to study age-related alterations in CD4+-CD4+ cell communications. In order to correlate patterns of 3G11, CD45RB, and CD44 expression with CD4+ cell function, cell subsets will be isolated based on the expressed levels of these markers and then evaluated for stimulation-dependent cell cycle progression and patterns of cytokine gene expression. Comparative analyses will be performed both with distinct subsets within the young group and with subset-matched preparations between age groups. Finally, the cell-mixing experiments described above will be extended to include evaluations of subset-subset communications among CD4+ cells from young mice, and potential alterations in these communications with advancing mouse age. Results from these studies should further our understanding of functional heterogeneity in the CD4+ cell compartment of healthy individuals, and of the consequences of aging on the representation and competence of CD4+ cell subsets.