The Role of HS1 in T Cell Activation

描述(由申请人提供)：肌动蛋白动力学在T细胞功能的几乎所有方面都发挥着关键作用。尽管对T细胞肌动蛋白反应的调节知之甚少，但HS1是一个关键的参与者，它是一种与狼疮有遗传联系的肌动蛋白调节蛋白。我们最近发现，HS1是免疫突触肌动蛋白聚合所必需的，也是导致IL2启动子激活的信号事件所必需的。在这里，我将测试HS1促进T细胞激活的机制。在目标1中，将使用流式细胞术分析HS1缺陷小鼠的T细胞亚群和激活标记。将测试T细胞功能的细胞生物学方面，包括肌动蛋白反应、免疫突触形成、信号事件、细胞因子产生和细胞毒性。在目标2中，将进行结构-功能分析，以在分子水平上更全面地了解HS1的作用。HS1-/-T细胞将用各种结构域或点突变进行逆转录病毒转导，并分析T细胞激活的特征。此外，还将分析HS1与Vav1和PLCGamma等关键信号分子的磷酸化依赖关联的作用。

DESCRIPTION (provided by applicant): Actin dynamics play a key role in nearly all aspects of T cell function. Though the regulation of T cell actin responses are poorly understood, one key player is HS1, an actin regulatory protein with genetic links to Lupus. We have recently discovered that HS1 is required for actin polymerization at the immune synapse, and for signaling events leading to IL2 promoter activation. Here, I will test the mechanisms by which HS1 facilitates T cell activation. In Aim 1, the T cell compartment of HS1-deficient mice will be analyzed using flow cytometry for subset and activation markers. Cell biological aspects of T cell function will be tested, including actin responses, immune synapse formation, signaling events, cytokine production, and cytotoxicity. In Aim 2, structure-function analysis will be conducted to more fully understand the role of HS1 on a molecular level. HS1-/- T cells will be retrovirally transduced with various domain or point mutants and analyzed for hallmarks of T cell activation. In addition, the role of phosphorylation-dependent association of HS1 with key signaling molecules such as Vav1 and PLCgamma will be analyzed.