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.

项目摘要/摘要： CD8+ T细胞分化为细胞毒性T淋巴细胞（CTL），以直接接合恶性细胞并引起其 通过细胞毒性颗粒的胞吐作用裂解。但是，这些对肿瘤反应的基础的调节是不明显的 定义且通常不成功，比较对急性病毒感染的反应。此外，研究具有 表明虽然抑制信号阻滞可以恢复某些T细胞功能，但不会导致全局表观遗传 重编程功能失调的细胞。然而，基础研究阐明了因素和机制 CD8 T细胞中的染色质结构和转录对肿瘤和病毒感染反应 确定如何实现这一目标。 为了解决这些问题，我有兴趣定义转录因子runx3和染色质调节器MLL1 分别进行工作，以实现基因组广泛的转录物表达，染色质可及性和抑制作用 CTL中的受体表达浸润三重负乳腺癌。我提供了runx3和 MLL1表达水平可以操纵PD-1表达，并且MLL1表达与Runx3相关。我 假设通过研究这两个基因如何独立工作并以协调方式工作，我可以定义 编程PD-1表达的基因调节和染色质访问性网络，更广泛地， 了解更多有关CTLS渗透非淋巴组织的遗传结构。要做，我建议两个 具体目的：阐明runx3在抗肿瘤响应过程中如何计划CD8+ T细胞分化 了解MLL1在确定CTL功能在肿瘤微环境中的作用。 两种目标都将利用用淋巴细胞标记的鼠三重阴性乳腺癌模型E0771 绒毛膜炎病毒抗原GP33可以在拟议的实验中实现抗原特异性肿瘤靶向。在 AIM 1，我将确定Runx3的行为以及如何相关的关键遗传和表观遗传景观 到PD-1功能。先前的研究表明，RUNX3对于产生非淋巴和肿瘤是必要的 居住权，还为抑制性基因（例如PD-1）的表达编程。通过研究这些功能，我可以 确定该顶端转录因子可以通过哪种途径以及如何影响PD-1表达。在 AIM 2，我将研究MLL1在类似途径中的作用。通过体外RNAi鉴定了MLL1 筛选调节共抑制基因的染色质调节剂。从这个屏幕MLL1和使基因产生的基因 在MLL1/2复合物上，很大程度上与抑制PD-1表达有关。通过查看MLL1在 TME内的CTL及其在可访问性和甲基化方面促进的变化，我可以理解如何 染色质的这些变化指导肿瘤中的CTL命运。结合理解Runx3和 基因之间的关系，这将为基本遗传结构提供详细的证据 肿瘤内的基本CTL积累和维护。