Distinctive role of ORAI3 channels in the effector T cell response

ORAI3 通道在效应 T 细胞反应中的独特作用

• 批准号: 10054359
• 负责人: Yousang Gwack
• 金额: $ 19.5万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10054359
• 关键词: Autoantigens; Autoimmunity; Cell physiology; Cells; Comparative Study; Cysteine; Environment; Exhibits; Experimental Autoimmune Encephalomyelitis; Family; Family member; Future; Genetic; Goals; Graft Rejection; Knock-out; Knockout Mice; Knowledge; Laboratories; Mediating; Molecular; Outcome; Oxidative Stress; Oxides; Pathogenicity; Pattern; Phenotype; Physiological; Production; Proteins; Reactive Oxygen Species; Regulation; Residual state; Resistance; Role; Signal Transduction; Solid; Structure; Structure-Activity Relationship; T cell response; T cell therapy; T-Cell Activation; T-Cell Receptor; T-Lymphocyte; T-Lymphocyte Subsets; Therapeutic; Tissues; Work; autoreactive T cell; base; biophysical properties; cell type; cytokine; druggable target; effector T cell; extracellular; in vivo; innovation; knockout animal; member; novel; response; small molecule; therapeutic target

PROJECT SUMMARY The goal of this proposal is to understand the discrete roles of the highly druggable targets, ORAI proteins in T cells for potential therapeutic exploitation. T cells require high and sustained levels of Ca2+ signaling for activation. Ca2+ signaling triggered by T cell receptor stimulation is primarily mediated by CRAC (Ca2+ release- activated Ca2+) channels that consist of the pore subunits, ORAI proteins. ORAI family members, ORAI1, ORAI2, and ORAI3, share a similar structure and can mediate CRAC currents but display distinct expression patterns and biophysical properties. Orai1 knockout (KO) effector T cells exhibit a reduction in Ca2+ entry, cytokine expression, and pathogenicity but also showed significant residual activity (20-40% of WT cells). These observations suggest that either ORAI2 or ORAI3 also contributes to Ca2+ entry in effector T cells. We find that, while deletion of Orai2 marginally influenced the function of effector T cells, Orai3 deletion substantially decreased Ca2+ entry and cytokine production. ORAI3 shares biophysical properties with ORAI1 but is unique in its resistance to inactivation by elevated intracellular Ca2+ levels and oxidative stress (e.g., reactive oxygen species, ROS) due to the absence of cysteine residues in its extracellular loop region. Based on these findings, the central hypothesis is that ORAI3 should be necessary for the in vivo effector T cell response in inflamed tissues. We propose to determine 1) the physiological outcomes of Orai3 deletion in effector T cells and 2) the distinctive role of ORAI3 homomultimeric channels in the effector T cell response. The proposed work is highly innovative because this study will determine the unknown role of ORAI3 in effector T cell responses. It will also define the distinct molecular identity of Ca2+ channels in T cell subsets. The idea to define the unique role of ORAI3 under oxidative stress at the inflamed tissue is conceptually innovative. This study to understand the physiological outcomes of blocking heteromeric or homomeric ORAI3 channels in the effector T cell response will have a significant positive impact on future therapeutic exploitation of the ORAI channels to treat autoimmunity or transplant rejection.

项目摘要 这项计划的目的是了解高度药物化的靶点，奥赖蛋白在T细胞中的独立作用。 细胞进行潜在的治疗开发。T细胞需要高水平和持续的Ca 2+信号传导， activation.由T细胞受体刺激触发的Ca 2+信号传导主要由CRAC（Ca 2+释放-释放）介导。 激活的Ca 2+）通道，其由孔亚基、奥赖蛋白组成。奥赖家族成员，口腔依赖1， ORAI 2和ORAI 3具有相似的结构，可以介导CRAC电流，但表现出不同的表达 模式和生物物理特性。Orai 1敲除（KO）效应T细胞表现出Ca 2+进入的减少， 细胞因子表达和致病性，但也显示出显著的残留活性（WT细胞的20-40%）。 这些观察结果表明，ORAI 2或ORAI 3也有助于效应T细胞中的Ca 2+进入。我们 我发现，虽然Orai 2的缺失对效应T细胞的功能有轻微影响，但Orai 3的缺失 显著降低Ca 2+内流和细胞因子产生。ORAI 3与ORAI 1具有相同的生物物理特性 但其独特之处在于其对升高的细胞内Ca 2+水平和氧化应激引起的失活的抗性（例如， 活性氧类（ROS），这是由于其细胞外环区域中不存在半胱氨酸残基。基于 基于这些发现，中心假设是，ORAI 3对于体内效应T细胞是必需的， 炎症组织的反应。我们建议确定1）Orai 3缺失的生理结果， 效应T细胞和2）ORAI 3同源多聚体通道在效应T细胞应答中的独特作用。 这项工作是高度创新的，因为这项研究将确定ORAI 3在 效应T细胞应答。它还将定义T细胞亚群中Ca 2+通道的不同分子身份。 在炎症组织中定义ORAI 3在氧化应激下的独特作用的想法是概念性的。 新颖啊本研究旨在了解阻断异聚体或同聚体ORAI 3的生理结果， 在效应T细胞反应中的通道将对未来的治疗开发产生重大的积极影响 奥赖通道治疗自身免疫或移植排斥。