Regulation of Follicular T cell Responses in the Lung by Ion Channels

项目摘要 这项应用的总体目标是了解T细胞中的离子通道如何调节免疫反应 感染流感病毒的肺部感染。流感是主要的健康风险，影响着美国数百万患者 以及世界范围内。CD4T细胞在支持生发中心B细胞产生中和作用中起关键作用 针对流感病毒的抗体，并成为记忆B细胞，它们共同提供对 再感染。CD4T细胞的功能受离子通道的调节，离子通道介导钙离子内流和 其他离子。钙释放激活钙通道(CRAC)，由ORAI1蛋白在细胞内形成 质膜是T细胞中特征性最强的通道之一。它调停了一种特定的和必要的 钙内流的一种形式，即储存操作的钙内流(SOCE)，之所以称为SOCE，是因为它是由钙离子的释放触发的 来自内质网的钙。钙离子释放激活基质相互作用分子1(STIM1)和 STIM2，并导致ORAI1 CRAC通道的开放。人类ORAI1或STIM1基因突变研究 废除SOCE导致免疫缺陷的患者因T细胞功能受损而反复感染 以及产生病原体特异性抗体。这种缺陷被STIM1/STIM2双缺位所模仿 小鼠，其CD4T细胞无法发育为滤泡T辅助细胞(TFH)并帮助B细胞成熟为 病毒感染后生发中心B细胞。我们发现T细胞中缺乏STIM1/STIM2的小鼠不能产生 感染淋巴细胞性脉络膜脑膜炎病毒(LCMV)或接种 流感病毒。本申请的重要目标是了解TFH小区中的CRAC信道 控制肺部对流感感染的免疫应答及其分子机制的研究 通过CRAC通道控制流感中TFH细胞的发育和功能。除了CRAC 通道，大约有600个离子通道和转运体在哺乳动物中表达，但到目前为止，只有少数是 为促进T细胞介导的免疫反应而建立。我们假设其他离子通道 此外，CRAC通道在调节TFH细胞依赖性体液免疫中发挥重要作用 流行性感冒。然而，到目前为止，还没有系统地解决这个问题的研究，这是我们的 T细胞生理学和适应性免疫知识。我们将解决这一差距，并系统地筛选 和表征调节TFH细胞对流感的体液免疫反应的离子通道 活着。我们研究的长期目标是确定离子通道和它们调节的下游分子 可以在治疗上有针对性地增强对流感感染的体液免疫和疫苗接种。自.以来 许多离子通道是质膜蛋白，它们可被小分子抑制剂或 生物制品，如单抗，调节其功能和对流感的免疫反应。

Project Summary The overall goal of this application is to understand how ion channels in T cells regulate immune responses to pulmonary infection with influenza virus. Influenza is major health risk and affect millions of patients in the US and worldwide. CD4 T cells play a critical role in supporting germinal center B cells to produce neutralizing antibodies against influenza virus and to become memory B cells, which together provide immunity against reinfection. The function of CD4 T cells is regulated by ion channels that mediate the influx of calcium and other ions. The calcium release-activated calcium (CRAC) channel, which is formed by ORAI1 proteins in the plasma membrane, is one of the best characterized channels in T cells. It mediates a specific and essential form of calcium influx, store-operated Ca2+ entry (SOCE), so called because it is triggered by the release of calcium from the endoplasmic reticulum. Ca2+ release activates stromal interaction molecule 1 (STIM1) and STIM2 and results in the opening of ORAI1 CRAC channels. Mutations in ORAI1 or STIM1 genes in human patients that abolish SOCE cause immunodeficiency with recurrent infections due to impaired T cell function and production of pathogen-specific antibodies. This defect is mimicked by STIM1/STIM2 double-deficient mice, whose CD4 T cells fail to develop into follicular T helper (TFH) cells and to help B cells mature into germinal center B cells after viral infection. We found that mice lacking STIM1/STIM2 in T cells cannot produce virus-specific antibodies upon infection with lymphocytic choriomeningitis virus (LCMV) or vaccination with influenza virus. Important goals of this application are to understand whether CRAC channels in TFH cells control pulmonary immune responses to infection with influenza and to characterize the molecular mechanisms by which CRAC channels control the development and function of TFH cells in influenza. Besides the CRAC channel, about 600 ion channels and transporters are expressed in mammals, but to date only a few are established to contribute to T cell-mediated immune responses. We hypothesize that other ion channels besides the CRAC channel play important roles in regulating TFH cell-dependent humoral immunity to influenza. However, no studies have systematically addressed this question so far, which is a major gap in our knowledge of T cell physiology and adaptive immunity. We will address this gap and systematically screen for and characterize ion channels that regulate TFH cell-dependent humoral immune responses to influenza in vivo. The long-term goal of our study is to identify ion channels and downstream molecules they regulate that can be targeted therapeutically to enhance humoral immunity to influenza infection and vaccination. Since many ion channels are plasma membrane proteins, they are accessible to small molecule inhibitors or biologicals such as monoclonal antibodies to modulate their function and immune responses to influenza.