Enhancing the Effectiveness of Immunotherapies by T Cell Epigenetic Reprogramming

通过 T 细胞表观遗传重编程增强免疫疗法的有效性

• 批准号: 10737264
• 负责人: Hazem E. Ghoneim
• 金额: $ 64.01万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-05 至 2028-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10737264
• 关键词: Acceleration; Address; Adoptive Transfer; Agonist; Back; Biological Models; Breast Adenocarcinoma; CD8-Positive T-Lymphocytes; CRISPR/Cas technology; CTLA4 gene; Cancer Patient; Cell physiology; Cells; Chromatin; Chronic; Clinical; DNA Methylation; DNMT3a; Data; Effectiveness; Endowment; Enzymes; Epigenetic Process; Equilibrium; Failure; Functional disorder; Genes; Genetic Transcription; Glioma; Goals; Grant; Human; Immune response; Immunotherapy; In Vitro; Infection; Knowledge; Link; Lymphocytic choriomeningitis virus; Malignant Neoplasms; Mediating; Memory; Methods; Modeling; Molecular Target; Morbidity - disease rate; Mus; Nature; Pathway interactions; Patients; Pre-Clinical Model; Refractory; Rejuvenation; Reporting; Resistance; Role; Route; Signal Pathway; Signal Transduction; Specificity; System; T cell differentiation; T-Lymphocyte; Technology; Testing; Therapeutic; Transforming Growth Factor beta; Transgenic Organisms; Translating; Viral; Viral Cancer; Virus; Virus Diseases; antagonist; chromatin remodeling; chronic infection; cytotoxic; cytotoxic CD8 T cells; epigenome; exhaust; exhaustion; experimental study; functional restoration; immune checkpoint blockade; in vitro Model; in vivo; in vivo Model; insight; melanoma; mortality; novel; novel strategies; prevent; progenitor; programmed cell death protein 1; programs; receptor; refractory cancer; response; restraint; retroviral transduction; stem; stemness; success; synergism; tool; transcriptome; tumor

PROJECT SUMMARY Cancer and chronic virus infections are significant causes of morbidity and mortality. While cytotoxic CD8 T cells are the main killers of tumors or virus-infected cells, persistent stimulation of CD8 T cells during chronic infections or cancer results in a gradual loss of their cytotoxic function as T cells progress towards a fully- exhausted state. While immune checkpoint blockade (ICB) therapy allows partially-exhausted CD8 T cells to functionally recover by blocking inhibitory signals, terminally-exhausted T cells remain nonresponsive to this therapy. The inability of terminally-exhausted T cells to recover after ICB may explain why many cancer patients fail to mount durable responses to ICB. We recently showed that de novo DNA methylation programming is causally linked to the progression of T cells toward terminal exhaustion and poor response to ICB. Importantly, we discovered that targeting T cell-intrinsic epigenetic programs synergized the efficacy of ICB during chronic infection or cancer. Yet, the following questions represent major gaps in our current understanding of T cell exhaustion: (1) How are these epigenetic changes acquired in exhausted T cells? (2) What are the upstream signals that regulate the specificity of de novo DNA methylation programs in exhausted versus functional T cells? (3) Can we reverse the epigenetic programming in exhausted T cells to the functional state while avoiding transformation? Bridging these gaps will allow us to identify and target factors that apply “epigenetic brakes” to CD8 T cell function. To address these questions, we have developed a novel in-vitro model of stable human T cell dysfunction as a tractable tool that can guide our in-vivo experiments by providing first-line mechanistic studies. First, we will employ cutting-edge approaches, such as CRISPR-Cas9 gene editing and retroviral transduction, to test the hypothesis that specific tumor microenvironmental signals regulate epigenetic programming in persistently stimulated CD8 T cells, which promotes their resistance to ICB therapy. We aim to block and/or revert the progression toward the terminally-exhausted state by targeting components of this signaling pathway while promoting counteracting pathways. Second, we aim to rebalance specific microenvironmental signals to restore functionality and response in terminally-exhausted T cells. Using novel in- vitro model systems of T cell dysfunction and complementary in-vivo models of chronic viral infection and cancer, as well as cutting-edge technologies to profile DNA methylation, open chromatin landscape, and transcriptome in CD8 T cells, our proposed studies can determine if targeting specific factors can remodel chromatin back into an accessible state at effector and/or stemness-associated genes, leading to functionally-rejuvenated T cells. These proposed studies will provide insights into how epigenetic programming can be reversed during progression to T cell exhaustion that can be translated to reprogram terminally-exhausted T cells in clinical settings, ultimately enhancing the efficacy of T cell immunotherapies.

项目概要 癌症和慢性病毒感染是发病和死亡的重要原因。而细胞毒性CD8 T 细胞是肿瘤或病毒感染细胞的主要杀手，慢性过程中持续刺激CD8 T细胞 感染或癌症会导致 T 细胞逐渐丧失细胞毒性功能。 疲惫状态。虽然免疫检查点阻断 (ICB) 疗法允许部分耗尽的 CD8 T 细胞 通过阻断抑制信号来功能恢复，最终耗尽的 T 细胞对此保持无反应 治疗。 ICB 后最终耗尽的 T 细胞无法恢复可能解释了为什么许多癌症患者 未能对 ICB 做出持久的反应。我们最近表明 DNA 从头甲基化编程是 与 T 细胞走向终末衰竭和对 ICB 反应不佳有因果关系。重要的是， 我们发现，针对 T 细胞内在表观遗传程序可协同 ICB 在慢性疾病期间的功效。 感染或癌症。然而，以下问题代表了我们目前对 T 细胞理解的主要差距 耗竭：(1) 这些表观遗传变化是如何在耗竭的 T 细胞中获得的？ (2)上游有哪些 调节衰竭 T 细胞与功能 T 细胞中从头 DNA 甲基化程序特异性的信号？ (3) 我们能否将耗尽的 T 细胞的表观遗传编程逆转至功能状态，同时避免 转型？弥合这些差距将使我们能够识别并瞄准那些应用“表观遗传刹车”的因素 CD8 T 细胞功能。为了解决这些问题，我们开发了一种新型的稳定人类 T 细胞体外模型 细胞功能障碍作为一种易于处理的工具，可以通过提供一线机制来指导我们的体内实验 研究。首先，我们将采用尖端方法，例如CRISPR-Cas9基因编辑和逆转录病毒 转导，检验特定肿瘤微环境信号调节表观遗传的假设 对持续刺激的 CD8 T 细胞进行编程，从而促进其对 ICB 治疗的抵抗。我们的目标是 通过针对该状态的成分来阻止和/或恢复向最终疲惫状态的进展 信号通路，同时促进抵消通路。其次，我们的目标是重新平衡具体的 微环境信号可恢复最终耗尽的 T 细胞的功能和反应。使用新颖的in- T 细胞功能障碍的体外模型系统和慢性病毒感染和癌症的补充体内模型， 以及描绘 DNA 甲基化、开放染色质景观和转录组的尖端技术 在 CD8 T 细胞中，我们提出的研究可以确定针对特定因子是否可以将染色质重塑回 效应子和/或干性相关基因的可接近状态，导致 T 细胞功能恢复活力。 这些拟议的研究将提供关于如何在过程中逆转表观遗传编程的见解。 进展至 T 细胞耗竭，可转化为在临床中重新编程最终耗竭的 T 细胞 设置，最终增强 T 细胞免疫疗法的功效。