Epigenetic modification of hematopoietic stem and progenitor cells in inflammation-induced differentiation

炎症诱导分化中造血干细胞和祖细胞的表观遗传修饰

• 批准号: 10699991
• 负责人: Brandon T Tran
• 金额: $ 4.77万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-10-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10699991
• 关键词: ATAC-seq; Affect; Blood; Bone Marrow; Cell Differentiation process; Cell physiology; Cells; Chromatin; Chronic; DNA Methylation; DNA Modification Methylases; DNMT3a; Data; Differentiated Gene; Disease; Dose; Engraftment; Enhancers; Epigenetic Process; Exposure to; Genetic Transcription; Goals; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Histones; Histopathology; Immune; Immune response; Immunologic Stimulation; Impairment; Individual; Infection; Infection prevention; Inflammation; Inflammatory; Interferon Type II; Knock-out; Laboratory Finding; Macrophage; Measures; Mediating; Modeling; Modification; Morbidity - disease rate; Multipotent Stem Cells; Mus; Mycobacterium avium; Mycobacterium avium-intracellulare Infection; Myelogenous; Myeloid Cells; Myelosuppression; Organ; Outcome; Pilot Projects; Process; Production; Signal Transduction; Source; Stimulus; Stress; Techniques; Transplant Recipients; Transplantation; Work; Writing; antimicrobial; chronic infection; epigenetic regulation; epigenome; epigenomics; exhaustion; experimental study; gene network; graft failure; hematopoietic engraftment; hematopoietic stem cell differentiation; hematopoietic stem cell self-renewal; histone modification; immune function; improved; improved outcome; in vivo; insight; mortality; post-transplant; preservation; prevent; promoter; prophylactic; response; self-renewal; stem cell function; therapeutic development; transcriptome sequencing

Project Summary Infections are the number one cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) patients. Infections contribute to delayed or failed engraftment of hematopoietic stem and progenitor cells (HSPCs). To study the mechanism underlying infection-related impaired HSPC function, our lab has utilized a Mycobacterium avium infection model and discovered that chronic infection depletes HSCs by impairing self- renewal and promoting myeloid differentiation – through increased activation and transcription of myeloid differentiation genes such as Batf2, Fosb, and Jun– via an interferon-gamma (IFNγ)-dependent mechanism. Further, the lab showed that inflammation-induced myeloid differentiation is epigenetically driven, as the knockout of DNA methyltransferase DNMT3A led to suppression of the myeloid differentiation response. Based on these data from our group’s previous studies, I hypothesize that HSPCs undergo a malleable epigenetic reprogramming in response to IFNγ that promotes myeloid differentiation and affects downstream immune responses. By defining the extent of epigenetic reprogramming, I seek to identify strategies to preserve HSC function despite infectious stress and thereby improve HSCT outcomes. Whereas our lab showed that IFNγ-dependent changes in DNA methylation contribute to HSC differentiation and exhaustion during chronic infection, the impact of IFNγ stimulation on histone modifications, another key mechanism of epigenetic regulation, has not been studied in HSPCs. Therefore, the first objective is to determine whether IFNγ induces histone modifications in HSPCs to promote myeloid differentiation. Specifically, I will use epigenomic sequencing techniques CUT&RUN-seq and ATAC-seq to determine the changes in histone modifications and chromatin accessibility in HSPCs under inflammatory stress. Next, I will identify which pre-stimulated HSPC subpopulations are functionally reprogrammed by transplanting M. avium- stimulated HSPC subpopulations into naïve recipients and challenging the recipients 3 months later with M. avium. Finally, I will investigate the malleability of these epigenetic modifications by exposing M. avium- stimulated HSPCs to subsequent high-dose LPS. I will perform RNA-seq, CUT&RUN-seq, and ATAC-seq, and immune challenge experiments post-transplant to determine whether HSPCs exposed to LPS after M. avium stimulation show altered differentiation responses compared to those exposed to M. avium alone. Overall, the work in this proposal will uncover the mechanisms by which IFNγ promotes myeloid differentiation and HSC exhaustion during chronic inflammation and enable the development of therapeutic approaches to prevent graft loss in the early post-transplant period.

项目摘要 感染是造血干细胞移植中发病率和死亡率的第一名 （HSCT）患者。感染导致造血茎和祖先的延迟或失败的植入 细胞（HSPC）。为了研究与感染相关的HSPC功能的基础机制，我们的实验室已使用 一种鸟分枝杆菌感染模型，发现慢性感染通过损害自我损害来耗尽HSC 通过增加的激活和转录，更新和促进髓样分化 - 通过干扰素 - γ（IFNγ）依赖性机制等分化基因，例如BATF2，FOSB和JUN-。 此外，该实验室表明，炎症引起的髓样分化是表观遗传驱动的，因为 DNA甲基转移酶DNMT3A的敲除导致骨髓分化反应的抑制。基于 关于我们小组以前研究的这些数据，我假设HSPC经历了可延展的表观遗传学 重新编程，以响应促进髓样分化并影响下游免疫的IFNγ 回答。通过定义表观遗传重编程的程度，我试图确定保留HSC的策略 功能dospite感染压力，从而改善HSCT结果。 而我们的实验室表明，IFNγ依赖性DNA甲基化的变化有助于HSC 慢性感染期间的分化和疲惫，IFNγ刺激对组蛋白修饰的影响， 表观遗传调节的另一个关键机制尚未在HSPC中研究。因此，第一个目标 是确定IFNγ是否诱导HSPC中的组蛋白修饰以促进髓样分化。 具体而言，我将使用表观基因组测序技术剪切和run-seq和atac-seq来确定 在炎症应激下，HSPC中组蛋白修饰和染色质可及性的变化。接下来，我会的 通过移植Avium- 将HSPC亚群刺激到幼稚的接受者中，并在3个月后与M.挑战受体。 鸟。最后，我将通过暴露鸟杆菌 - 刺激HSPC到随后的高剂量LPS​​。我将执行RNA-Seq，Cut＆Run-Seq和Atac-Seq，以及 移植后的免疫挑战实验，以确定M. Avium后HSPC是否暴露于LPS 与单独暴露于鸟杆菌的刺激相比，刺激显示出改变的分化反应。总体而言， 该提案中的工作将发现IFNγ促进髓样分化和HSC的机制 慢性炎症期间的疲惫并能够开发治疗方法以防止移植 移植后早期的损失。