Temporal control of differentiation and epigenetics of Exhausted CD8 T cells by Tox

Tox 对耗竭 CD8 T 细胞的分化和表观遗传学的时间控制

• 批准号: 10096485
• 负责人: E. John Wherry
• 金额: $ 53.94万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-22 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10096485
• 关键词: Address; Affect; Antigens; Binding; Binding Sites; Biological; Biology; CD8-Positive T-Lymphocytes; CRISPR screen; Cells; Chromatin; Chronic; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Complement; Complex; DNA Binding; Data; Defect; Dependence; Developmental Biology; Epigenetic Process; Excision; Exons; Foundations; Functional disorder; Genes; Genetic Transcription; Genome; Genomics; Goals; HIV; Hepatitis B Virus; Hepatitis C virus; Heterogeneity; Histones; Immune response; Immunity; Immunologics; Infection; LoxP-flanked allele; Lymphocytic choriomeningitis virus; Maintenance; Malignant Neoplasms; Mediating; Modeling; Molecular; Morbidity - disease rate; Mus; PD-1 blockade; PD-1 pathway; Pathway interactions; Patients; Play; Population; Property; Reporter; Role; Signal Transduction; T-Lymphocyte; T-bet protein; Testing; Therapeutic; Therapeutic Intervention; Transcriptional Regulation; Transferase; Virus Diseases; Work; base; chromatin remodeling; chronic infection; clinical effect; deletion analysis; disorder control; exhaust; exhaustion; flexibility; imprint; improved; in vivo; insight; loss of function; mortality; novel; novel therapeutics; prevent; progenitor; programmed cell death protein 1; programs; recruit; response; therapeutic target; transcription factor

SUMMARY T cell exhaustion is common during chronic infections and cancer and limits control of disease. Targeting TEX by blocking pathways such as PD-1:PD-L can reinvigorate these cells leading to dramatic clinical effects in cancer. However, most patients do not receive durable clinical benefit. Although PD-1 pathway blockade re-invigorates TEX function, and results in transcriptional changes, there is little change in the chromatin landscape and functional changes are not sustained. Thus, our ability to target TEX for therapeutic benefit in cancer and chronic infections is limited by the epigenetic inflexibility of these cells. A better understanding of the initiation, stability and reversibility of TEX epigenetic identity should reveal new therapeutic possibilities. We and others have recently identified Tox as the epigenetic lineage programmer of TEX. Without Tox, TEX cannot form. Tox is required to initiate chromatin remodeling for TEX but represses terminal TEFF differentiation. However, the mechanisms of how Tox programs epigenetics are unclear. A major question is what happens to chromatin landscape and TEX differentiation if Tox is removed in established TEX. Addressing this question is a major goal. TEX heterogeneity is also now pointing to a developmental biology hierarchy with discreet, functionally relevant stages of differentiation – or TEX subsets - controlled by transcription factor circuits. These subsets also differ epigenetically suggesting key roles for Tox that are as yet untested as well as opportunities. These observations suggest a key role for Tox in the epigenetic identity of TEX but raise key questions about the ongoing role of Tox once TEX are established. Our overall hypothesis is that inducible deletion of Tox in established TEX will reveal mechanisms of epigenetic stability of TEX and opportunities for therapeutic improvement during chronic infections and cancer. We will test this hypothesis in the following Aims: AIM 1: TEST WHETHER DELETION OF TOX IN ESTABLISHED TEX ALTERS TEX DIFFERENTIATION, TRANSCRIPTIONAL PROGRAM, OPEN CHROMATIN LANDSCAPE AND/OR DYNAMICS OF TEX SUBSETS. We hypothesize that removal of Tox in established TEX will revert the TEX epigenetic program and will be associated with functional, differentiation and transcriptional changes that will be augmented by PD-1 blockade and/or removal of antigen. To test this idea we will use new inducible Tox deletion strategies combined with deep mechanistic interrogation of the cellular developmental biology, transcriptional and epigenetic program and response to PD-1 pathway blockade. AIM 2: TEST HOW COMPLEMENTARY OR DOWNSTREAM EPIGENETIC OR TRANSCRIPTIONAL CIRCUITS COOPERATE WITH TOX IN TEX. We hypothesize that a combination of in vivo CRISPR screening and candidate testing will reveal epigenetic and transcriptional mechanisms of Tox in TEX. We will use this CRISPR approach together with enforced expression strategies and a novel Tox-driven inducible Cre reporter to define the molecular and genomic mechanisms of Tox-mediated initiation and maintenance of the TEX lineage.

概括 在慢性感染和癌症中，T细胞耗尽很常见，并限制了对疾病的控制。针对Tex by 阻断PD-1：PD-L等途径可以振兴这些细胞，从而导致癌症急剧的临床作用。 但是，大多数患者没有获得持久的临床益处。虽然PD-1途径封锁重新染色 TEX功能，并导致转录变化，染色质景观几乎没有变化 功能变化无法持续。这是我们针对Tex以在癌症和慢性的治疗益处的能力 感染受这些细胞的表观不灵活性的限制。更好地理解该计划，稳定性 Tex表观遗传身份的可逆性应揭示新的治疗可能性。 我们和其他人最近将TOX确定为Tex的表观遗传谱系程序员。没有毒品，Tex不能 形式。需要托克斯来启动Tex的染色质重塑，但复制终端TEFF分化。然而， 托克斯计划表观遗传学的机制尚不清楚。一个主要的问题是染色质会发生什么 景观和Tex​​差异化，如果在既定的Tex中删除TOX。解决这个问题是一个主要目标。 Tex异质性现在也指出具有谨慎，功能相关的发育生物学层次结构 由转录因子电路控制的分化阶段（或Tex子集）。这些子集也不同 表观遗传表明，尚未经过测试和机会的托克斯的关键角色。 这些观察结果表明，毒物在Tex的表观遗传身份中起着关键作用，但提出了有关 一旦建立了Tex，Tox的持续角色。我们的总体假设是托克斯在 已建立的TEX将揭示Tex的表观遗传稳定性和治疗机会的机制 慢性感染和癌症期间的改善。我们将在以下目的中检验这一假设： AIM 1：测试已建立的Tex中删除TOX是否改变了Tex的分化，转录 程序，开放染色质景观和/或Tex子集的动态。我们假设去除毒物 在已建立的TEX中，将恢复Tex表观遗传学计划，并将与功能，差异化有关 以及通过PD-1阻滞和/或抗原去除将增加的转录变化。测试这个 想法我们将使用新的诱导毒Tox缺失策略，并结合对 细胞发育生物学，转录和表观遗传程序以及对PD-1途径阻滞的反应。 AIM 2：测试互补或下游表观遗传或转录电路如何与 托克斯在德克萨斯。我们假设体内CRISPR筛查和候选测试的结合将揭示 Tex中TOX的表观遗传和转录机制。我们将使用这种CRISPR方法 强迫表达策略和一种新型的托克斯驱动的诱导CRE记者来定义分子和 Tex介导的倡议和Tex谱系维持的基因组机制。