Potassium Channel Trafficking in Geometrically Patterned Immunological Synapses

描述（由申请方提供）：淋巴细胞通过一系列事件对抗原作出反应，这些事件构成T细胞活化过程。当抗原是病原体或癌细胞时，T细胞活化是必要的和有益的，但当免疫系统将身体自身细胞的成分识别为外来时，T细胞活化就变得不受欢迎了。这种异常反应发生在自身免疫性疾病中。因此，研究正常和自身免疫性T细胞的活化过程是至关重要的。T细胞活化通过T细胞与抗原呈递细胞（APC）的接触和免疫突触（IS）的形成而启动。IS是一个高度组织化的信号区，形成于T/APC界面，是激活反应充分发展所必需的。虽然IS形成过程的各个方面已经被彻底研究，但对潜在的膜离子事件知之甚少。Kv1.3钾通道在T细胞中表达，在那里它们与T细胞受体复合物和IS处的各种信号分子一起区室化。Kv1.3通道在T细胞活化过程中发挥重要作用，因为它们调节下游功能事件所必需的Ca2+内流。事实上，这些通道的抑制终止了免疫应答，因此Kv1.3阻断剂正在开发中作为新型免疫抑制剂。尽管这些通道的意义，其在T细胞的IS区室化的功能后果尚未确定。从我们的实验室的初步数据表明，Kv1.3的位置内的IS是必要的，以调节通道的功能和改变Kv1.3通道定位在IS中已被观察到的自身免疫性疾病SLE。在本申请中，我们将测试Kv1.3通道在免疫突触中的募集及其在该结构中的特定位置对于调节通道活性是必要的，因此它影响T细胞活化的结果的假设。具体来说，我们将设计人工APC样表面，允许在IS内的预定位置靶向隔离Kv1.3蛋白，并同时测量下游功能事件。这些研究将建立工程蛋白表面的可行性，研究离子通道区室化的IS，特别是解决的问题，如何在IS中的离子通道的位置决定T细胞/APC相互作用的结果。此外，这些研究将使理解的影响，在离子通道招募到IS的异常对整体T细胞功能的病理条件。 公共卫生相关性：淋巴细胞的功能，因此也是功能障碍，部分是由细胞膜中的Kv1.3通道控制的。我们有兴趣研究Kv1.3通道在T细胞和抗原呈递细胞之间的接触点的位置如何影响通道功能的细节。为此，我们提出了一种结合纳米技术和人工抗原呈递细胞样表面的新方法。

DESCRIPTION (provided by applicant): Lymphocytes respond to antigens with a series of events that constitute the T cell activation process. T cell activation is necessary and beneficial when the antigen is a pathogen or a cancer cell, but it becomes undesirable when the immune system identifies components of the body's own cells as foreign. This aberrant response occurs in autoimmune diseases. Thus studying the activation process of normal and autoimmune T cells is of primary importance. T cell activation is initiated by contact of the T cell with the antigen presenting cell (APC) and formation of the immunological synapse (IS). The IS is a highly organized signaling zone that forms at the T/APC interface and is needed for full development of the activation response. Although various aspects of the process of IS formation have been thoroughly investigated, the underlying membrane ionic events are poorly understood. Kv1.3 potassium channels are expressed in T cells where they compartmentalize together with the T cell receptor complex and various signaling molecules at the IS. Kv1.3 channels play an important role during T cell activation as they regulate the Ca2+ influx necessary for downstream functional events. Indeed, inhibition of these channels terminates the immune response and therefore Kv1.3 blockers are under development as novel immunosuppressive agents. Despite the significance of these channels, the functional consequences of their compartmentalization in the IS of T cells are yet to be determined. Preliminary data from our laboratory suggest that Kv1.3 location within the IS is necessary to regulate the channel function and alterations in Kv1.3 channel localization in the IS have been observed in the autoimmune disease SLE. In this application we will be testing the hypothesis that Kv1.3 channels' recruitment in the immunological synapse and their specific location within this structure is necessary for regulation of the channel activity and consequently it influences the outcome of T cell activation. Specifically we will engineer artificial APC-like surfaces allowing targeted sequestration of Kv1.3 proteins in a predetermined location within the IS and simultaneous measurement of downstream functional events. These studies will establish the feasibility of engineered protein surfaces for studying ion channel compartmentalization in the IS, specifically addressing the question of how the position of ion channels in the IS determines the outcome of T cell/APC interactions. Furthermore, these studies will enable understanding of the implications that abnormalities in ion channel recruitment into the IS have on overall T cell function in pathological conditions. PUBLIC HEALTH RELEVANCE: Lymphocytes function, and also therefore malfunction, is in part controlled by Kv1.3 channels in the cell membrane. We are interested in studying details of how the location of Kv1.3 channels in the contact point between T cells and antigen presenting cells affects the channels' function. To do this we propose a novel method combining nanotechnology and artificial antigen presenting cell-like surfaces.