Biochemical and Spatial Regulation of IKKg/NEMO During T Cell Activation

描述（由申请人提供）：NF-κB转录因子的适当调节是对病原体产生免疫反应和免疫系统正常稳态所必需的。相反，过度的NF-κ b依赖性炎症可以帮助驱动自身免疫性疾病的发展和肿瘤的形成。因此，了解NF-κB家族转录因子是如何通过影响该通路的不同类型受体的信号传导来控制的是很重要的。在T细胞被抗原激活的过程中，TCR和CD28以及许多信号蛋白在经历磷酸化和泛素化等翻译后修饰的同时被重组成不同的结构。尽管IKK复合物积聚在免疫突触中心的TCR-富域，但受体信号是由接触外围的TCR“微簇”发起的。我们发现IKK复合体被迅速招募到含有TCR和Zap70的信号微簇中，而不是SLP-76。我们的成像研究还揭示了可能参与IKKγ向TCR微团簇传递和/或其下调的其他IKKγ池。然而，关于IKKγ的亚细胞调控及其在T细胞活化中的作用，许多重要的问题仍有待回答。如果我们最终要利用这些知识来操纵tcr介导的NF-κB活化以达到治疗目的，那么开展这样的研究是很重要的。我们假设TCR/CD28激活经典的NF-κB通路需要对接头蛋白IKKγ/NEMO进行复杂的亚细胞调控。因此，在Aim 1中，我们将确定Zap70和Lck在将IKK复合物募集到TCR微团簇中的作用。在Aim 2中，我们将定义Carma1和相关蛋白在IKK复合体空间调节中的作用。最后，在Aim 3中，我们将定义含有总IKK复合物和活性IKK复合物的亚细胞区室

DESCRIPTION (provided by applicant): Proper regulation of NF-κB transcription factors is required to mount immune responses to pathogens and for the normal homeostasis of the immune system. Conversely, excessive NF-κB-dependent inflammation can help to drive the development of autoimmune disease and the formation of tumors. In this light, it is important to know how NF-κB family transcription factors are controlled by signaling through the different types of receptors that impinge on this pathway. During T cell activation by antigen, TCR and CD28, and numerous signaling proteins, are reorganized into distinct structures while undergoing well-described post-translational modifications, such as phosphorylation and ubiquitination. Although the IKK complex accumulates in the TCR-rich domain at the center of the immune synapse, receptor signals are initiated by TCR 'microclusters' in the periphery of the contact. We have found that the IKK complex is rapidly recruited to signaling microclusters containing the TCR and Zap70, but not SLP-76. Our imaging studies have also revealed additional pools of IKKγ that may be involved in delivery of IKKγ to TCR microclusters and/or its down-regulation. However, a number of important questions remain to be answered regarding the sub-cellular regulation of IKKγ and its role in T cell activation. Carrying out such studies is important, if we are to eventually exploit this knowledge to manipulate TCR-mediated NF-κB activation for therapeutic purposes. We hypothesize that TCR/CD28 activation of the classical NF-κB pathway requires complex sub-cellular regulation of the adaptor protein IKKγ/NEMO. Thus, in Aim 1, we will determine the role of Zap70 and Lck in recruitment of the IKK complex to TCR microclusters. In Aim 2, we will define the role of Carma1 and associated proteins in spatial regulation of the IKK complex. Finally, in Aim 3 we will define the sub-cellular compartment(s) containing total and active IKK complexes