Exploring the intersection of hypoxia and epigenetic modifiers in tumor-mediated CD8 T cell exhaustion

探索缺氧和表观遗传修饰剂在肿瘤介导的 CD8 T 细胞耗竭中的交叉作用

基本信息

批准号：
10533919
负责人：
Brinley Rhodes Ford
金额：
$ 3.26万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-01 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10533919
关键词：
Antitumor Response Automobile Driving CD8-Positive T-Lymphocytes CD8B1 gene Cell Differentiation process Cell physiology Cells Chemicals Chromatin Chromatin Remodeling Factor Epigenetic Process Equilibrium Exhibits Functional disorder Gene Expression Genes Genetic Models Genetic Transcription Histones Hypoxia Immune Response Genes Immune response Immunology Immunotherapy In Vitro Inflammatory Response Pathway Measures Mediating Methylation Modification Mus Oxygen Phenotype Play Regulation Research Resistance Role Signal Transduction Supporting Cell System T cell differentiation T cell response T-Lymphocyte Techniques Testing Training Tumor Immunity Tumor-Infiltrating Lymphocytes anti-PD1 therapy base cancer immunotherapy cytokine cytotoxic CD8 T cells demethylation epigenome exhaust exhaustion experience experimental study histone demethylase histone methylation histone methyltransferase histone modification improved in vitro Assay in vivo inhibitor innovation neoplastic cell novel pluripotency prevent programmed cell death protein 1 receptor response stem cells stem-like cell stemness therapeutic target tumor tumor hypoxia tumor microenvironment

项目摘要

PROJECT SUMMARY CD8+ T cells are a fundamental component of the anti-tumor response; however, tumor-infiltrating CD8+ T cells (TIL) are rendered dysfunctional by the tumor microenvironment. CD8+ TIL display an exhausted phenotype with decreased cytokine expression and increased expression of co-inhibitory receptors (IRs), such as PD-1 and Tim-3. The acquisition of IRs marks the progression of dysfunctional TIL from progenitors (PD1lo) to terminally exhausted (PD1hiTim3+). We have described a distinct increase in bivalent genes in terminally exhausted CD8+ TIL, which are characterized by presence of both the active mark H3K4me3 and the repressive mark H3K27me3, as well as low gene expression. While this state has traditionally been found in pluripotent cells and described as a “poised” state, new research suggests that it is not specific to stem-like cells. The increase in bivalent chromatin in terminally exhausted cells suggests increased methylation in response to the tumor microenvironment. We suspect that hypoxia-mediated regulation of histone modifiers is responsible for this increase in bivalent genes and plays a critical role in mediating dysfunction. Understanding the role of bivalent genes and their regulation will provide crucial information about the regulation of exhaustion in the tumor microenvironment. This proposal seeks to use a combination of traditional immunology techniques and sequencing-based experiments to better understand the regulation of these chromatin features. We hypothesize that dysregulated chromatin modifiers of H3K27me3 drive bivalency and exhaustion in terminally exhausted T cells and can be targeted to improve anti-tumor immunity. We will test this hypothesis in two aims; we will 1) determine whether inhibition of H3K27 demethylation in hypoxia is sufficient to drive bivalency and terminal exhaustion using demethylase inhibitors and innovative in vitro assays of T cell exhaustion. We will 2) determine whether Ezh2 can be targeted to prevent bivalency in exhaustion using both inhibitors of Ezh2 activity and inducible deletion of Ezh2 in in vitro and in vivo systems, respectively. The presence of bivalent genes specific to terminally exhausted TIL supports the notion that while exhausted cells are epigenetically resistant to immunotherapy, such as anti-PD1 treatment, chromatin and transcriptional regulators can be targeted to reinvigorate exhausted TIL by increasing expression of key functional genes to improve the anti-tumor response.

项目摘要 CD8+ T细胞是抗肿瘤反应的基本组成部分。但是，肿瘤浸润CD8+ T细胞（TIL）通过肿瘤微环境使功能失调。 CD8+ TIL显示出耗尽的表型随着细胞因子表达降低和共抑制受体（IR）的表达增加，例如PD-1和 Tim-3。 IRS的获取标志着功能障碍TIL从祖细胞（PD1LO）到终端的发展耗尽（PD1HITIM3+）。我们描述了终末耗尽的CD8+中二价基因的明显增加 TIL的特征是有活性Mark H3K4me3和反射标记H3K27Me3的存在以及低基因表达。传统上在多能细胞中发现了这种状态，并描述了作为一个“昂贵”状态，新的研究表明，它不是特定于干细胞的。二价增加终止耗尽的细胞中的染色质表明对肿瘤响应甲基化增加微环境。我们怀疑缺氧介导的组蛋白修饰剂调节是为此负责的二价基因的增加并在介导功能障碍中起关键作用。了解二价的作用基因及其调节将提供有关肿瘤疲劳调节的关键信息微环境。该建议试图结合传统的免疫学技术和基于测序的实验，以更好地了解这些染色质特征的调节。我们假设H3K27me3的染色质修饰剂失调，使双价性和精疲力尽终止耗尽的T细胞，可以靶向以提高抗肿瘤免疫力。我们将测试这个两个目标的假设；我们将1）确定在缺氧中抑制H3K27脱甲基化是否足够使用脱甲基酶抑制剂和T细胞创新的体外测定，以驱动双价性和末端衰竭精疲力尽。我们将2）确定是否可以针对EZH2，以防止使用两者的疲惫 EZH2活性的抑制剂和EZH2在体外和体内系统的可诱导缺失。特有终端耗尽的二价基因的存在支持以下概念：耗尽的细胞表观遗传对免疫疗法具有抗性，例如抗PD1治疗，染色质和转录可以通过增加关键功能基因的表达到将调节器作为振兴耗尽的止血物。改善抗肿瘤反应。