RAS PROTEINS IN T CELL ACTIVATION AND DIFFERENTIATION

描述（改编自应用摘要）： 拟议的研究是为了描述T细胞的效力如何 受体（TCR）信号影响Ras家族小分子的活性。 GTP酶。将通过改变CD 45的贡献来观察“I”CR信号。 蛋白酪氨酸磷酸酶和通过使用不同亲和力的配体， TCR。这些研究将探讨小GTP酶Ras和 相关蛋白Rapl并不是彼此孤立地起作用，而是保持 在密切功能关系中，可以有效地整合和修改 TCR复合物诱导的信号转导事件。 申请人 假设根据CD 45的同种型和T细胞的强度， 细胞受体连接，拮抗或协同排列 Ras和Rap 1之间的关系，这些不同的关系 其可影响淋巴细胞行为如T细胞早期发育， 将成熟细胞分化为Th 1或“I”h2辅助细胞亚群， 记忆T细胞池的产生。 在目标1中，生物化学和功能 实验将检测单个CD 45亚型对Ras和Rapl的影响， 关于其直接下游目标和直接上游目标， 刺激因子、Raf激酶和鸟嘌呤核苷酸交换因子 （GEF）分别。因为个人.. CD 4：亚型被认为是 差异性改变T细胞对TCR诱导信息的反应性 在这些研究中获得的结果将模拟目标2中的方法， 用高亲和力野生型肽或低亲和力野生型肽刺激TCR 将分析改变的肽配体。特别是，这些 刺激，申请人将评估Ras的生化活性， Rap 1，并检查RAP 1的功能特性，以增强或抑制Ras-1。 对丝裂原活化蛋白激酶（MPK）的信号传导作用。 申请人 计划最终提供显性消极或构成性积极 Ras或Rap 1的突变体进入原代T细胞，并测试它们的潜力， 干扰免疫过程中发生的功能极化过程 反应了解控制激活的分子机制 而幼稚T辅助细胞的分化对于一个 各种免疫学病症，包括过敏性、感染性和 自身免疫性疾病 此外，T细胞调节的基础研究 小GTP酶对淋巴细胞的作用在癌症领域具有广泛的适用性 发病机制

DESCRIPTION (adapted from application abstract): The long term objective of the proposed research is to characterize how the potency of the T cell receptor (TCR) signals affects the activity of the Ras family of small GTPases. 'I'CR signals will be viewed by altering the contribution of the CD45 protein tyrosine phosphatase and by using ligands of varying affinities for the TCR. Thee studies will explore the hypothesis that small GTPases Ras and related protein Rapl do not act in isolation from each other but rather remain in close functional relationships which may effectively integrate and modify signal transduction events induced by the TCR complex. The applicant hypothesizes that depending on the isoform of CD 45 and the strength of the T cell receptor ligation, either antagonistic or synergistic arrangements between Ras and Rap1 are included, and that these different relationships which may influence lymphocyte behaviors such as T cell early development, differentiation of matured cells into Th1 or 'I'h2 helper subsets, and the generation of memory T cell pools. In aim 1, the biochemical and functional experiments will examine the effect s of single CD45 isoforms on Ras and Rapl with respect to their immediate downstream targets and the direct upstream stimulators, the Raf kinases and the guanine nucleotide exchange factors (GEFs) respectively. Because individual.. CD4: isoforms are believed to differentially modify responsiveness of T cells to TCR induction information obtained in these studies will model approaches in aim 2 in which the effects of TCR stimulation with high affinity wild type peptide or low affinity altered peptide ligand, will be analyzed. In particular, following, these stimulations, the applicant will evaluate biochemical activities of Ras and Rapl, and examine functional properties of RAP1 to enhance or suppress Ras- signaling effects on mitogen activated protein kinase (MPK). The applicant plans to eventually deliver the dominant negative or constitutive active mutants of Ras or Rap1 into primary T cells and to test their potential to interfere with the functional polarization processes occurring during immune response. Understanding the molecular mechanisms controlling the activation and differentiation of naive T helper cells is crucial with regard to a variety of immunological conditions including allergic, infectious and autoimmune diseases. In addition, basic studies on the regulation of T lymphocytes by small GTPases have broad applicability to the field of cancer pathogenesis.