The Impact of Donor Hematopoietic DNMT3A Mutations in Stem Cell Transplant Recipients

项目摘要/摘要 造血细胞移植是治疗恶性血液病的重要手段。 (HM)。它的成功取决于捐赠者的造血细胞建立长期造血和 免疫介导性消除残留的恶性细胞。克隆性造血(CH)是与年龄相关的 可检测到的体细胞突变改变其生物功能和炎症输出的状态 造血细胞，在非移植人群中与不良后果一致相关。通过 研究了1727对HCT供受者，我发现捐赠者中的CH很常见，而且失活突变 在基因中，DNMT3A是最常见的变化。我的初步数据显示供体DNMT3A-CH是 通过降低HM复发风险，改善全球受者结局，但也 增加了一部分受者移植失败的风险。根据这些数据和已知的函数 在造血细胞中的DNMT3A，我假设供者DNMT3A-CH I在HCT受者中观察到的效果 是由于DNMT3A突变的长期造血干细胞植入和随后的功能改变 在成熟的DNMT3A突变的白细胞亚群中，特别是T细胞。为了检验这一假设，我提出了以下建议 目的有二：(1)研究DNMT3A-CH对HCT后正常和受损造血功能的影响。这就做 使用基因组、免疫表型和单细胞技术来定义特征，包括细胞 移植到受体体内的供体DNMT3A突变的隔室。然后我将专注于阐明生物学 供体DNMT3A-CH受者发生移植物衰竭的风险。(2)界定DNMT3A-CH在供体- 移植后植入的T细胞。我将使用基因组、免疫表型和单细胞技术 检测供体DNMT3A突变对术后受者T细胞组成和功能的影响 特别关注DNMT3A突变如何调节T细胞耗竭的发展。 然后我将专门评估捐赠者T细胞中的DNMT3A突变如何影响免疫逃避的途径 用于急性髓系白血病复发病例。从这些研究中获得的信息将提供 对移植后造血和免疫监测生物学的新见解可能会有深远的影响 供者选择的含义和增强移植物抗白血病效应的策略。与 在拟议的实验中，我概述了一个五年职业发展计划，目标是成为一名 翻译移植研究中的独立调查者。我已经组建了一个全球顾问委员会 公认的造血、移植免疫学和生物统计学专家，提供实验投入 以及在这些领域的具体培训。达纳-法伯癌症研究所，该研究所拥有一项杰出的研究 社区，并且有成功指导独立内科科学家的长期记录，是一个理想的选择 为完成这些实验和实现我的短期和长期职业目标提供环境。

PROJECT SUMMARY/ABSTRACT Hematopoietic cell transplant (HCT) is an important treatment modality for patients with hematologic malignancy (HM). Its success depends on the ability of donor hematopoietic cells to establish long-term hematopoiesis and immunologically mediated elimination of residual malignant cells. Clonal hematopoiesis (CH) is an age-related condition in which detectable somatic mutations alter the biologic function and inflammatory output of hematopoietic cells, and in non-transplant populations is uniformly associated with adverse outcomes. By studying 1727 HCT donor-recipient pairs, I found that CH in donors is common and that inactivating mutations in the gene DNMT3A are the most frequent alterations. My preliminary data shows that donor DNMT3A-CH is associated with improved global recipient outcomes, mediated by a reduced risk of HM relapse, but also increases the risk of graft failure in a subset of recipients. Based on these data and the known function of DNMT3A in hematopoietic cells, I hypothesize that the effects of donor DNMT3A-CH I observe in HCT recipients are due to engraftment of DNMT3A-mutated long-term hematopoietic stem cells and subsequent altered function in mature DNMT3A-mutant leukocyte subsets, particularly T cells. To test this hypothesis, I propose the following two aims: (1) Determine the effect of DNMT3A-CH on normal and impaired hematopoiesis following HCT. I will use genomic, immunophenotypic, and single-cell technologies to define the characteristics, including cellular compartment, of donor DNMT3A mutations that engraft in recipients. I will then focus on elucidating the biology of graft failure developing in recipients of donor DNMT3A-CH. (2) Define the effect of DNMT3A-CH in donor- engrafted T-cells after transplantation. I will use genomic, immunophenotypic, and single-cell techniques to determine the effect of donor DNMT3A mutations on T-cell composition and function in recipients after transplantation, focusing specifically on how DNMT3A mutations modulate the development of T-cell exhaustion. I will then specifically assess how donor DNMT3A mutations in T cells affect the pathways of immune evasion utilized by relapsing cases of acute myeloid leukemia. The information gained from these studies will provide new insights into the biology of post-transplant hematopoiesis and immune surveillance that could have profound implications for donor selection and strategies to augment the graft-versus-leukemia effect. In concert with the proposed experiments, I have outlined a five-year career development plan aimed at the goal of becoming an independent investigator in translational transplant research. I have assembled an advisory committee of globally recognized experts in hematopoiesis, transplant immunology, and biostatistics, to provide experimental input and specific training in these fields. Dana-Farber Cancer Institute, which harbors an outstanding research community and has a long track record for successful mentorship of independent physician scientists, is an ideal environment for completion of these experiments and realization of my short and long-term career goals.