Understanding mechanisms and consequences of T cell co-receptor regulated RNA maturation

项目摘要/摘要。 T 细胞的独特之处在于它们需要两个激活信号才能发挥功能。这种分离 T 细胞受体 (TCR) 和辅助受体（例如 CD28）之间的权力，允许精确调节 T 细胞反应。近年来，T细胞辅助受体已成为免疫治疗的重要靶点。 自身免疫性疾病和癌症。在自身免疫阻断中，激活共受体可以减少破坏性 T 细胞对正常组织的影响，而在癌症中，阻断抑制性共受体可以激活 T 细胞 针对恶性细胞的反应。然而，共受体靶向免疫疗法往往无法产生所需的效果 结果。此外，关于共受体如何协调无数细胞的知识仍然存在很大差距。 使 T 细胞获得功能特性的变化。本拨款申请中提出的项目将 探索 T 细胞辅助受体协调 RNA 成熟变化的新机制 T 细胞产生足够数量并制造关键分子，使其能够杀死其他细胞。这些杀手 T 细胞具有控制传染病、控制肿瘤生长或破坏能力的特性 自身免疫性疾病中的健康组织。初步研究提供证据表明 CD28 信号传导协调 通过对 RNA 结合蛋白 ARS2 的影响，新制备的 RNA 的选择性剪接发生了许多变化。 选择性剪接允许一个基因通过改变 RNA 的产生方式来编码多种不同的蛋白质 由该基因组装而成。我们发现，在活化的 T 细胞中，CD28-ARS2 依赖的选择性剪接 编码代谢酶丙酮酸激酶的 mRNA 有利于产生称为 PKM2 的异构体，其中 已知的增殖促进特性。拟议的研究旨在 1) 确定 PKM2 的选择性剪接是否有效 诱导 T 细胞如何利用营养物质促进增殖的变化，2) 检查 ARS2 如何调节替代方案 T 细胞中的剪接，以及 3) 确定选择性剪接中 CD28 调节的变化作为潜在的调节剂 免疫疗法。这些研究的长期目标是了解 RNA 结合蛋白和 RNA 如何 成熟在 T 细胞激活过程中塑造基因表达，并确定这种变化是否存在 基因调控机制可以在治疗上有针对性地改变癌症患者的 T 细胞功能，或 自身免疫性疾病。

Project Abstract/Summary. T cells are unique in their requirement for two activation signals to become functional. This separation of powers between the T cell receptor (TCR) and co-receptors, such as CD28, allows exquisite regulation of T cell responses. In recent years, T cell co-receptors have emerged as valuable targets of immunotherapy for autoimmune diseases and cancer. In autoimmunity blocking activating co-receptors can reduce the destructive effects of T cells on normal tissue, while in cancer blocking inhibitory co-receptors can activate a T cell response against malignant cells. However, co-receptor targeted immunotherapy often fails to produce desired results. Moreover, there remain large gaps in knowledge of how co-receptors coordinate the myriad cellular changes that allow T-cells to gain functional properties. The project proposed in this grant application will explore a novel mechanism by which T cell co-receptors coordinate changes in RNA maturation important for T-cells to generate sufficient numbers and make key molecules that allow them to kill other cells. These killer properties underlie the ability of T cells to contain infectious diseases and control tumor growth or to damage healthy tissue in autoimmune diseases. Preliminary studies provide evidence that CD28 signaling coordinates many changes in alternative splicing of newly made RNAs through effects on the RNA binding protein ARS2. Alternative splicing allows one gene to code for several different proteins by changing how the RNA produced from that gene is assembled. We find that in activated T cells CD28-ARS2 dependent alternative splicing of the mRNA coding for metabolic enzyme pyruvate kinase favors production of an isoform, known as PKM2, with known proliferation promoting properties. Proposed studies seek to 1) determine if alternative splicing to PKM2 induces changes in how T cells use nutrients to fuel proliferation, 2) examine how ARS2 regulates alternative splicing in T cells, and 3) establish CD28 regulated changes in alternative splicing as potential modulators of immunotherapy. The long-term goals of these studies are to understand how RNA binding proteins and RNA maturation shapes gene expression during the process of T-cell activation and to determine if such mechanisms of gene regulation can be therapeutically targeted to alter T-cell function in patients with cancer or autoimmune diseases.