Decoding the epigenetic landscape that delineates T cell homeostatic proliferation from uncontrolled growth”

解码表观遗传景观，描绘 T 细胞稳态增殖与不受控制的生长 –

• 批准号: 10644128
• 负责人: Caitlin Zebley
• 金额: $ 26.38万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2028-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10644128
• 关键词: Acute; Adoptive Transfer; Animals; Antigens; Antitumor Response; Automobile Driving; Biological Assay; Biology; Blood Cells; CD8-Positive T-Lymphocytes; Cell Compartmentation; Cell Separation; Cells; Cellular immunotherapy; Chronic; Clonal Expansion; Clustered Regularly Interspaced Short Palindromic Repeats; Coupled; DNMT3a; Development; Dysmyelopoietic Syndromes; Elderly; Epigenetic Process; Event; Exhibits; Future; Gene Expression; Generations; Genes; Growth; Hematopoiesis; Heterogeneity; Homeostasis; Human; Immunize; Induced Mutation; Infection; Measures; Mediating; Memory; Mentors; Methylation; Modality; Modification; Molecular; Monitor; Mus; Mutate; Mutation; PD-1 blockade; PD-L1 blockade; Patients; Phenotype; Play; Program Sustainability; Proliferating; Protocols documentation; Psychological reinforcement; Regulator Genes; Rejuvenation; Reporting; Research; Role; Scientist; T cell differentiation; T memory cell; T-Cell Proliferation; T-Independent Antigens; T-Lymphocyte; T-Lymphocyte Subsets; Testing; Training; antigen-specific T cells; cancer immunotherapy; career development; cell growth; chimeric antigen receptor T cells; cohort; cytokine; design; exhaustion; experimental study; hematopoietic stem cell expansion; imprint; manufacture; next generation; novel; preservation; programs; response; stemness; uncontrolled cell growth; whole genome

PROJECT SUMMARY Epigenetic reinforcement of T cell exhaustion is a well-established barrier limiting multiple modalities of T cell- based immunotherapies for cancer. This proposal will investigate the specific epigenetic events that are coupled to one of the cardinal features of T cell exhaustion; a reduction in the T cell’s proliferative potential. Notably, disruption of the epigenetic regulators DNMT3A and TET2 has been reported to preserve the proliferative capacity of CD8 T cells in the setting of both chimeric antigen receptor (CAR) T cell chronic stimulation and PD- 1 blockade-mediated rejuvenation of endogenous T cells. Importantly, mutations in these genes have also been associated with clonal expansion of hematopoietic stem cells (HSCs) which occurs in the majority of otherwise healthy older adults. Such clonal hematopoiesis of indeterminate potential (CHIP) mainly results from mutations of three epigenetic regulators (DNMT3A, TET2, ASXL1). Despite disruption of DNMT3A and TET2 producing a similar T cell phenotype, a critical distinction is that DNMT3A KO T cells maintain antigen dependent homeostatic proliferation and TET2 KO T cells exhibit a hyperproliferative phenotype. ASXL1 has yet to be characterized, but we have recently determined that disruption of ASXL1 in T cells also preserves the cell’s proliferative potential in a PD-1 blockade setting. My research program is now well-poised to dissect the specific epigenetic modifications that are established by each of these discrete regulators to better define the molecular mechanism limiting the proliferative potential of T cells as they progress down the exhaustion developmental trajectory. I propose to test the hypothesis that CH-associated gene disruptions result in specific epigenetic programs that delineate memory T cell homeostasis versus a hyperproliferative state. To define these programs, I will pursue the following aims; 1) To define epigenetic programs mediated by CH- associated epigenetic regulators that promote a homeostatic versus hyperproliferative state during persistent antigen stimulation of T cells. 2) To determine if disruption of CH-regulators among naïve versus memory human T cells results in a hyperproliferative state in chronically stimulated CAR T cells. 3) To identify whether T cells isolated from myelodysplastic syndrome (MDS) patients with mutations in CH-associated epigenetic regulators exhibit epigenetic programs consistent with heightened proliferative ability. Completion of the proposed studies will define the epigenetic checkpoint(s) regulating T cell homeostatic proliferation from uncontrolled cell growth. Importantly, successful completion of this proposal will define the underlying programs that sustain T cell proliferative capacity for the design and manufacturing of next generation CAR T cell protocols. The proposed career development and training outlined in this application, in conjunction with the experimental studies, will advance my training as a clinician scientist by further establishing a novel research program that will put me on a path to independence.

项目摘要 T细胞耗尽的表观遗传增强是一个良好的障碍，限制了T细胞的多种方式 基于癌症的免疫疗法。该提案将调查耦合的特定表观遗传事件 到T细胞耗尽的主要特征之一； T细胞的增殖潜力降低。尤其， 据报道，表观遗传调节剂DNMT3A和TET2的破坏可保留增殖 CD8 T细胞在嵌合抗原受体（CAR）T细胞慢性刺激和PD的情况下的能力 1个封锁介导的内源性T细胞的修订。重要的是，这些基因中的突变也已经 与造血干细胞（HSC）的克隆膨胀相关 健康的老年人。这种不确定电势（芯片）的克隆造血作用主要是由于突变引起的 三个表观遗传调节剂（DNMT3A，TET2，ASXL1）。尽管DNMT3A和TET2破坏了 类似的T细胞表型，一个临界区别是DNMT3A KO T细胞维持抗原依赖性稳态 增殖和TET2 KO T细胞表现出高增殖表型。 ASXL1尚未表征，但是 我们最近确定，T细胞中ASXL1的破坏还保留了细胞增殖的潜力 在PD-1封锁设置中。我的研究计划现在已经很好地剖析了特定的表观遗传学 这些离散调节剂中的每一个都建立的修改以更好地定义分子 机制限制了T细胞在疲惫下进展时的增殖潜力 发展轨迹。我建议检验以下假设，即CH相关基因破坏导致 特定的表观遗传学程序描绘了记忆T细胞稳态与超增殖状态的特定表观遗传程序。到 定义这些程序，我将追求以下目标； 1）定义由CH-介导的表观遗传程序 相关的表观遗传调节剂在持续期间促进稳态与超增殖状态的相关表观调节剂 T细胞的抗原刺激。 2）确定幼稚与记忆中的CH调节剂是否破坏人类 T细胞在长期刺激的CAR T细胞中导致过度增殖状态。 3）确定是否T细胞 从骨髓增生综合征（MDS）中分离出与CH相关的表观遗传调节剂突变的患者 暴露的表观遗传学计划与增殖能力增强一致。拟议研究的完成 将定义从不受控制的细胞生长中调节T细胞稳态增殖的表观遗传检查点。 重要的是，该提案的成功完成将定义维持T细胞的基础计划 下一代汽车T细胞协议的设计和制造的增殖能力。提议 该应用程序中概述的职业发展和培训以及实验研究将 通过进一步建立一个新颖的研究计划，推进我作为临床科学家的培训 独立之路。