Dissecting the roles of Runx3 and Mll1 in dysfunctional T cell responses to tumors

剖析 Runx3 和 Mll1 在 T 细胞对肿瘤的功能失调反应中的作用

• 批准号: 10394017
• 负责人: Adam Joshua Getzler
• 金额: $ 0.59万
• 依托单位: SCRIPPS FLORIDA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10394017
• 关键词: Acute; Address; Antigen-Presenting Cells; Antigens; Antitumor Response; Apical; Automobile Driving; Binding; Binding Sites; Breast; CD8-Positive T-Lymphocytes; Cell physiology; Cells; Chromatin; Chromatin Structure; Clinical; Complex; Cytolysis; Cytoplasmic Granules; Cytotoxic T-Lymphocytes; Deposition; Development; Epigenetic Process; Exocytosis; Family member; Functional disorder; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Epistasis; Genetic Transcription; Immune Targeting; Immunity; In Vitro; Lead; Ligands; Link; Lymphocyte Function; Lymphocytic Infiltrate; Lymphocytic choriomeningitis virus; MLL gene; Maintenance; Mediating; Memory; Methylation; Modeling; Monoclonal Antibodies; Outcome; PD-1 blockade; Pathway interactions; Pattern; Phenotype; Play; Program Accessibility; RNA interference screen; RUNX3 gene; Regulation; Research; Residencies; Role; Signal Transduction; Solid Neoplasm; Stimulus; System; T cell differentiation; T cell response; T-Lymphocyte; Tissues; Transcript; Tumor Antigens; Tumor-Infiltrating Lymphocytes; Viral Antigens; Virus Diseases; Work; acute infection; cancer cell; chromatin modification; cytotoxic; experimental study; genetic architecture; genome-wide; histone methylation; immune checkpoint blockade; in vivo; interest; melanoma; methylation pattern; mouse model; next generation sequencing; novel; overexpression; programmed cell death protein 1; programs; protein expression; receptor; receptor expression; response; transcription factor; transcriptome sequencing; triple-negative invasive breast carcinoma; tumor; tumor microenvironment

Project Summary/Abstract: CD8+ T cells differentiate into cytotoxic T lymphocytes (CTLs), to directly engage malignant cells and cause their lysis via exocytosis of cytotoxic granules. However, the regulation underlying these responses to tumors is ill- defined and generally unsuccessful compared responses to acute viral infections. In addition, studies have shown that while inhibitory signal blockade can restore some T cell function, it does not lead to global epigenetic reprogramming of dysfunctional cells. Nevertheless, basic studies to clarify the factors and mechanisms that control chromatin structure and transcription in CD8 T cells reacting to tumors and viral infection are likely to identify how this can be achieved. To address these issues, I am interested in defining how transcription factor Runx3 and chromatin regulator Mll1 work separately and together to effect genome wide transcript expression, chromatin accessibility, and inhibitory receptor expression in CTLs infiltrating triple negative breast cancers. I provide evidence that both Runx3 and Mll1 expression levels can manipulate PD-1 expression and that Mll1 expression is linked to Runx3. I hypothesize that by studying how these two genes work independently and in a coordinated fashion I can define a network of gene regulation and chromatin accessibility that programs PD-1 expression, and more broadly, understand more about the genetic architecture of CTLs infiltrating non-lymphoid tissues. To do, I propose two specific aims: Elucidate how Runx3 programs CD8+ T cell differentiation during anti-tumor responses & Understand the role of Mll1 in determining CTL function in tumor microenvironments. Both aims will utilize a model of murine triple negative breast cancer, E0771, tagged with lymphocytic choriomeningitis virus antigen GP33 to allow for antigen specific tumor targeting in proposed experiments. In Aim 1, I will identify the key genetic and epigenetic landscapes through which Runx3 acts and how this relates to PD-1 function. Previous research has shown that Runx3 is necessary to generate non-lymphoid and tumor residency and also programs the expression of inhibitory genes such as PD-1. By studying these features, I can identify what pathways this apical transcription factor works through and how this effects PD-1 expression. In Aim 2, I will be investigating the role Mll1 plays in similar pathways. Mll1 was identified through an in vitro RNAi screen for chromatin regulators that modulated co-inhibitory genes. From this screen Mll1, and genes that make up the MLL1/2 complex, are heavily implicated in inhibiting PD-1 expression. By looking at how Mll1 functions in CTLs within the TME and what changes it promotes both in accessibility and methylation, I can understand how these changes in chromatin directs CTL fates in tumors. Combined with understanding Runx3 and the relationship between the genes, this will provide detailed evidence into the fundamental genetic architecture underlying CTLs accumulation and maintenance within tumors.

项目概要/摘要： CD 8 + T细胞分化为细胞毒性T淋巴细胞（CTL），直接与恶性细胞接触并引起其恶性增殖。 通过细胞毒性颗粒的胞吐作用溶解。然而，这些对肿瘤的反应背后的调节是病态的- 定义和一般不成功的比较反应急性病毒感染。另外研究 虽然抑制性信号阻断可以恢复一些T细胞功能，但它不会导致整体表观遗传学 重新编程功能失调的细胞。然而，基础研究，以澄清的因素和机制， 在对肿瘤和病毒感染反应的CD 8 T细胞中控制染色质结构和转录， 确定如何实现这一点。 为了解决这些问题，我有兴趣定义转录因子Runx 3和染色质调节因子Mll 1 单独或共同作用，以影响全基因组转录本表达、染色质可及性和抑制性， 浸润性三阴性乳腺癌中CTL受体表达。我提供的证据表明Runx 3和 Mll 1表达水平可以操纵PD-1表达，并且Mll 1表达与Runx 3相关。我 我假设通过研究这两个基因如何独立和协调地工作， 基因调控和染色质可及性的网络，其编程PD-1表达，更广泛地说， 了解更多关于浸润非淋巴组织的CTL的遗传结构。为此，我建议两个 具体目标：阐明Runx 3如何在抗肿瘤反应期间编程CD 8 + T细胞分化， 了解Mll 1在肿瘤微环境中决定CTL功能的作用。 两个目标都将利用小鼠三阴性乳腺癌模型E0771，用淋巴细胞标记， 脉络丛脑膜炎病毒抗原GP 33，以允许在所提出的实验中靶向抗原特异性肿瘤。在 目标1，我将确定Runx 3作用的关键遗传和表观遗传景观，以及它们之间的关系 PD-1功能先前的研究表明，Runx 3是产生非淋巴和肿瘤细胞所必需的。 它还可以编程抑制基因如PD-1的表达。通过研究这些特征， 确定这种顶端转录因子通过什么途径起作用，以及它如何影响PD-1表达。在 目标2，我将研究Mll 1在类似途径中的作用。通过体外RNAi技术鉴定Mll 1 筛选调节共抑制基因的染色质调节因子。从这个屏幕Mll 1，和基因，使 在MLL 1/2复合物上，与抑制PD-1表达密切相关。通过观察Mll 1在 TME内的CTL以及它在可及性和甲基化方面促进的变化，我可以理解它是如何改变的。 染色质的这些变化指导肿瘤中的CTL命运。结合对Runx 3和 基因之间的关系，这将提供详细的证据到基本的遗传结构 潜在的CTL在肿瘤内的积累和维持。