Tyrosine Kinases in Autoimmunity

描述(申请人提供)：免疫系统反应不当的免疫性疾病，如一些过敏性和自身免疫性疾病，显示T细胞抗原受体(TCR/CD3)异常诱导的信号事件。这可能包括细胞内钙离子的动员和肌动蛋白细胞骨架的重组。蛋白酪氨酸激酶ITK是这些事件的关键调节因子。因此，我们认为对ITK的研究对我们理解此类免疫性疾病具有重要意义。我们提出的假设是，ITK调控TCR/CD3诱导的重要信号转导事件，包括细胞内钙动员和肌动蛋白细胞骨架的重组。此外，我们认为ITK通过其不同的结构域来调节这些事件。鉴于这一假设，本提案将涉及以下三个具体目标： 1)ITK对T细胞发育和激活的结构要求。我们将用选定的突变ITK转基因基因重建ITK缺陷小鼠，这些基因已被证明具有有趣的表型。重组小鼠将被测试对T细胞发育、激活、转录激活和细胞因子产生的影响、TCR近端信号事件以及体内对病毒感染的反应。2)ITK对过敏性哮喘的调节作用的结构要求。在这些研究中，我们将利用具有特定目的的ITK转基因小鼠1。重组小鼠将在过敏性哮喘的实验模型中受到挑战，并将确定不同的ITK转基因表达对肺病理、T细胞增殖和细胞因子产生的影响。3)ITK参与TCR/CD3诱导的细胞骨架事件。我们将评估ITK在TCR/CD3诱导的肌动蛋白聚合中的参与，ITK与WASP的诱导相互作用，WASP与其他肌动蛋白聚合相关蛋白(如VASP和Arp2/3)的相互作用，以及这些相互作用的ILK结构要求，ITK介导的WASP的磷酸化在肌动蛋白聚合中的作用，以及ITK参与TCR/CD3介导的小GTP酶和核苷酸交换因子Vav的激活。

DESCRIPTION (provided by applicant): Immunological diseases where the immune system responds inappropriately, such as some allergic and autoimmune disorders, display aberrant T cell antigen receptor (TCR/CD3)-induced signaling events. These may include intracellular Ca++ mobilization and the reorganization of the actin cytoskeleton. The protein tyrosine kinase Itk is a critical regulator of these events. Therefore, we believe studies on Itk are important to our understanding of such immunological diseases. We propose the hypothesis that Itk regulates important TCR/CD3-induced signal transduction events including intracellular Ca++ mobilization and reorganization of the actin cytoskeleton. Furthermore, we propose that Itk regulates these events through its various structural domains. In view of this hypothesis the present proposal will address the following three specific aims: 1) Structural requirements of Itk on T cell development and activation. We will reconstitute Itk-deficient mice with selected mutant Itk transgenes that have been shown to display interesting phenotypes. Reconstituted mice will be tested for effects on T cell development, activation, transcriptional activation and cytokine production, TCR-proximal signaling events, and in vivo responses to viral infection. 2) Structural requirements of Itk on the modulation of allergic asthma. For these studies we will utilize the Itk transgenic mice of specific aim 1. Reconstituted mice will be challenged in an experimental model of allergic asthma and the effects of various Itk transgene expression on lung pathology, T cell proliferation, and cytokine production will be determined. 3) Involvement of Itk in TCR/CD3-induced cytoskeletal events. We will assess the involvement of Itk on TCR/CD3-induced actin polymerization, the inducible interaction of Itk with WASP, the interaction of WASP with other actin-polymerization related proteins (e.g. VASP and Arp2/3), and the Ilk structural requirements for these interactions, the role of the Itk-mediated phosphorylation of WASP on actin polymerization, and the involvement of Itk in TCR/CD3-mediated activation of small GTPases and the nucleotide exchange factor Vav.