Clonal hematopoiesis and graft-versus-host disease after hematopoietic stem cell transplantation

移植物抗宿主病(GVHD)是异基因造血干细胞移植(AllSCT)的主要并发症，造成相当大的死亡率和致残率。我们最近发现，接受异基因干细胞移植的异基因干细胞移植受者中，慢性移植物抗宿主病(CGVHD)的发生率增加，这些受者来自具有不确定潜能的克隆性造血者(CHIP)。另一个研究小组发现供体芯片与急性移植物抗宿主病有关。我们以前的临床工作表明，尤其是DNMT3A突变的供体干细胞与异基因SCT后GVHD频率的增加有关。虽然CHIP突变在炎症性血管疾病(如动脉粥样硬化性心血管疾病)发病机制中的重要作用已被阐明，但供体CHIP尤其是DNMT3A突变如何影响GVHD的细胞和分子机制尚不清楚。我们证明了血管病理是GVHD的一个标志，这是我们计划研究的克隆性造血和GVHD之间的明显联系。克隆性造血和GVHD之间的进一步可能联系是DNMT3A在调节T细胞反应以及控制髓系细胞的发育和功能方面的意义。在目前的项目中，我们将把Frederk Damm团队在克隆造血方面的经验与Olaf Penack团队在GVHD以及血管生物学方面的专业知识协同结合起来。本研究的目的是分析DNMT3A介导的GVHD调节的细胞和分子机制。我们将在标准的小鼠急性和慢性GVHD模型中使用DNMT3A/DNMT3A的基因修饰。此外，我们将把先前从DNMT3A突变个体和DNMT3A野生型个体中收集的人类白细胞转移到NSG小鼠身上，以研究DNMT3A突变在人源化GVHD模型中的作用。目的：1探讨DNMT3A/DNMT3A在实验性GVHD中的作用。目的2分析DNMT3A/DNMT3A在GVHD中的功能和机制。

Graft-versus-host disease (GVHD) is the main complication of allogeneic hematopoietic stem cell transplantation (alloSCT) causing considerable mortality and morbidity. We recently found that the frequency of chronic GVHD (cGVHD) is increased in alloSCT recipients receiving stem cell grafts from donors with clonal hematopoiesis of indeterminate potential (CHIP). Another group found a connection of donor CHIP with acute GVHD. Our previous clinical work demonstrates that in particular DNMT3A mutated donor stem cells associate with an increased GVHD frequency after alloSCT. While the important role of CHIP mutations in the pathogenesis of inflammatory vascular diseases, such as atherosclerotic cardiovascular disease, has been recently elucidated, cellular and molecular mechanisms how donor CHIP and in particular DNMT3A mutations influence the development of GVHD are unclear. We demonstrated that vascular pathology is a hallmark of GVHD, which is an obvious link between clonal hematopoiesis and GVHD that we are planning to investigate. Further possible links between clonal hematopoiesis and GVHD are the implication of DNMT3A in regulation of T cell responses as well as in control of myeloid cell development and function. In the current project we are going to synergistically combine the experience of Frederik Damm’s group in clonal hematopoiesis with the expertise of Olaf Penack’s group in GVHD as well as in vascular biology. The objective of this proposal is to analyze the cellular and molecular mechanisms of DNMT3A-mediated GVHD regulation. We will use genetic modification of DNMT3A/Dnmt3a in standard murine acute and chronic GVHD models. In addition, we will transfer previously collected human leukocytes from DNMT3A-mutated vs. DNMT3A-wildtype individuals to NSG mice to study the effect of DNMT3A mutations in a humanized GVHD model. The specific aims are: Aim 1 Investigation of the effect of DNMT3A/Dnmt3a on experimental GVHD Aim 2 DNMT3A/Dnmt3a functional and mechanistic analyses during GVHD The results from the planned experiments could contribute to a better understanding of the role of donor clonal hematopoiesis during GVHD and its regulation by DNMT3A.