Signal Transduction in T Lymphocyte Activation

描述（由申请人提供）：此资助的先前工作集中在两个方面 互补区域，即，蛋白激酶C-α的功能与调控 （PKCalpha），我们在1993年分离，和Syk家族PTKs与 它们在T细胞中的底物和靶点。最近的研究，包括我们自己的研究， 证明了PKC θ是免疫突触的关键成分 （IS）。PKC θ在成熟T细胞活化中起重要作用， 整合TCR/CD 28共刺激信号，导致NF-κ B活化 信号级联和AP-1。这些转录因子的诱导， 对于IL-2的产生和预防T细胞无反应性是必需的， 无反应性T细胞鉴于PKC θ在T细胞中的重要性， 激活和我们对这一领域的广泛承诺，我们将专注于我们的 建议研究PKC θ在Ag特异性T细胞中的功能和调节， 细胞，强调其在CD 28共刺激和无能的潜在作用。 首先，我们将阐明分子和生化机制， 决定了PKC θ选择性募集到IS及其活化， 包括推定的支架蛋白的身份，PI 3 K的作用，以及 PKC θ的IS定位的功能重要性。二是 将PKC θ与NF-κ B级联反应偶联的中间信号蛋白是 未知我们将使用Ag特异性野生型或PKC θ缺陷型T细胞， Jurkat T细胞与生物化学和遗传方法结合， 鉴定这些蛋白质，重点是NF-κ B的已知组分， MAPK信号级联。第三，我们将研究PKC θ在 转导CD 28共刺激信号并通过 采用选择性PKC θ干扰策略，或者相反，确定 组成型活性PKC θ是否可以拯救T细胞活化， CD 28缺陷型T细胞。这些研究将产生详细的了解， 建立了这种关键T细胞酶结构-功能关系 它在T细胞活化、共刺激和无反应性中作用，并提供了一种声音 为将来在T细胞中用作药物靶点奠定了基础。

DESCRIPTION (provided by applicant): Previous work on this grant focused on two complementary areas, i.e.,the function and regulation of protein kinase C-alpha (PKCalpha), which we isolated in 1993, and interactions of Syk-family PTKs with their substrates and targets in T cells. Recent studies, including our own, demonstrated that PKCtheta is a key component of the immunological synapse (IS). PKCtheta plays an essential role in mature T cell activation by integrating TCR/CD28 costimulatory signals leading to activation of the NF-kB signaling cascade and AP-1. Induction of these transcription factors, which is essential for IL-2 production and prevention of T cell anergy, is defective in anergic T cells. In view of this emerging importance of PKCtheta in T cell activation and our extensive commitment to this area, we will focus our proposed studies on the function and regulation of PKCtheta in Ag-specific T cells, with emphasis on its potential role in CD28 costimulation and anergy. First, we will elucidate the molecular and biochemical mechanism(s) that dictate the selective recruitment of PKCtheta to the IS and its activation, including the identity of putative scaffold protein(s), the role of PI3K, and the functional importance of the IS localization of PKCtheta. Second, the intermediate signaling proteins that couple PKCtheta to the NF-kB cascade are unknown. We will use Ag-specific wild type or PKCtheta-deficient T cells and Jurkat T cells in conjunction with biochemical and genetic approaches to identify these proteins, with emphasis on known components of the NF-kB and MAPK signaling cascades. Third, we will study the role of PKCtheta in transducing CD28 costimulatory signals and preventing T cell anergy by employing selective PKCtheta interfering strategies or, conversely, determining whether constitutively active PKCtheta can rescue T cell activation in CD28-deficient T cells. These studies will generate a detailed understanding of the structure-function relationship of this critical T cell enzyme, establish its role in T cell activation, costimulation, and anergy, and provide a sound basis for its future use as a drug target in T cells.