MEMORY T CELL DEVELOPMENT

本项目的目的是研究记忆CD4 T细胞的产生机制，以及记忆细胞的功能和生化特性。研究CD4记忆的实验系统使用表达转基因TCR （DO.11.10）的引物T细胞过继转移到正常受体中，其中抗原特异性细胞可以被定量跟踪和纯化。该项目的具体目标如下：1。记忆细胞产生和维持的刺激：将定义启动条件对记忆细胞产生的影响，以便建立初始T细胞扩增和分化与随后发展的记忆池大小之间的相关性。使用缺乏参与T细胞激活和稳态的分子（例如CD28， CD40L, IL-2, FasL）的敲除小鼠，我们将检查这些分子在记忆细胞发育中的作用。2. 记忆T细胞的功能反应：长寿命记忆DO.11 T细胞将从移植受体中分离出来，并分析其对抗原、共刺激和细胞因子的体外反应。这些记忆细胞对免疫原性和耐受性抗原的回忆反应将被定义。3. 记忆T细胞中的基因表达和生化改变：我们将检查记忆细胞中选定基因的激活和信号通路，以确定可能有助于这些细胞存活和功能属性的生化变化。我们将重点关注促凋亡和抗凋亡蛋白，细胞因子和细胞因子受体，以及可能解释记忆细胞相对共刺激物独立性和耐受性抵抗的细胞内生化中间体。记忆细胞中表达的基因的生理重要性将通过逆转录病毒介导的转移将这些基因引入T细胞，并检查对记忆细胞生成的影响来研究。因此，这一建议解决了免疫记忆的基本问题，这是有效接种疫苗的基础。确定控制记忆T细胞发育的刺激和基因，应该会导致更合理的疫苗开发策略，而不是通常使用的主要经验方法。

The objective of this project is to examine the mechanisms of generation of memory CD4 T cells, and the functional and biochemical characteristics of memory cells. The experimental system for studying CD4 memory uses adoptive transfer of primed T cells expressing a transgenic TCR (DO.11.10) into normal recipients, in which the antigen-specific cells can be followed quantitatively and purified. The specific aims of the project are the following: 1. Stimuli for the generation and maintenance of memory cells: The influence of priming conditions on the generation of memory cells will be defined, in order to establish correlations between the initial T cell expansion and differentiation and the size of the memory pool that develops subsequently. Using knockout mice lacking molecules involved in T cell activation and homeostasis (e.g., CD28, CD40L, IL-2, FasL), we will examine the role of these molecules in the development of memory cells. 2. Functional responses of memory T cells: Long-lived memory DO.11 T cells will be isolated from transfer recipients and analyzed for ex vivo responses to antigen, costimulation, and cytokines. The recall responses of these memory cells to immunogenic and tolerogenic forms of antigen will be defined. 3. Gene expression and biochemical alterations in memory T cells: We will examine the activation of selected genes and signaling pathways in memory cells to identify biochemical changes that may contribute to the survival and functional attributes of these cells. We will focus on pro- and anti-apoptotic proteins, cytokines and cytokine receptors, and intracellular biochemical intermediates that may account for the relative costimulator independence and tolerance resistance of memory cells. The physiologic importance of genes expressed in memory cells will be examined by introducing these genes into T cells by retrovirus-mediated transfer, and examining effects on memory cell generation. Thus, this proposal addresses basic issues of immunologic memory, which is fundamental to effective vaccination. Defining the stimuli and genes that control memory T cell development should lead to more rational strategies for vaccine development than the largely empirical approaches that are in common use.