DOT1L, reconstitution of plasmacytoid dendritic cells and alloimmunity

DOT1L，浆细胞样树突状细胞和同种免疫的重建

• 批准号: 10582730
• 负责人: YI ZHANG
• 金额: $ 64.78万
• 依托单位: HACKENSACK UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-11-23 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10582730
• 关键词: Adoptive Transfer; Allogenic; Allografting; Autoimmunity; Blood; CSF3 gene; Cancer Patient; Cell Therapy; Cells; Cellular Stress; Cessation of life; Clinic; Clinical; Complication; Data; Defect; Dendritic Cells; Development; Disease; Epigenetic Process; FLT3 ligand; Functional disorder; Generations; Granulocyte-Macrophage Colony-Stimulating Factor; Hematologic Neoplasms; Hematological Disease; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Human; Immune; Immunity; Immunosuppression; Impairment; Individual; Infection; Inflammatory; Interferons; Life; Maintenance; Malignant Neoplasms; Methods; Methylation; Modeling; Molecular; Morbidity - disease rate; Multipotent Stem Cells; Mus; Oxidative Stress Induction; Pathway interactions; Patients; Population; Production; Proliferating; Property; Recovery; Regulation; Repression; Role; Signal Transduction; Specific qualifier value; Stimulus; Suppressor-Effector T-Lymphocytes; System; T cell response; T-Cell Activation; T-Lymphocyte; Testing; Translating; Transplant Recipients; Work; disorder prevention; graft versus host disease induction; graft vs host disease; hematopoietic cell transplantation; improved; in vivo; isoimmunity; mortality; novel; novel strategies; peripheral blood; prevent; progenitor; programmed cell death ligand 1; reconstitution; transcription factor; translational potential

PI: Yi Zhang Graft-versus-host disease (GVHD), a cause of life-threatening complication in cancer patients following allogeneic hematopoietic cell transplantation, causes reconstitution of donor plasmacytoid dendritic cells (pDCs) to fail, as pDCs are critical for immune protection and tolerance. However, little is known about GVHD-associated pDC molecular defects and the precise effect of donor pDCs on GVHD in cancer. We used both murine and human systems to uncover the mechanisms by which GVHD induces donor pDC defects. GVHD depleted donor multipotent progenitors (MPPs) that sustain pDCs, leading to impaired pDC generation. MPP loss was associated with decreased numbers of MPP-producing hematopoietic stem cells (HSCs) and oxidative stress-induced death of remaining proliferating MPPs; this correlates with the common clinical observation of low blood counts in the setting of GVHD. In our models, alloreactive T cells produce GM-CSF to inhibit MPP expression of Tcf4, the transcription factor essential for pDC development, subverting MPP production of pDCs. GM-CSF did not affect the maturation of pDC precursors. Notably, enhanced recovery of donor pDCs upon adoptive transfer early after allogeneic HSC transplantation (allo-HSCT) repressed GVHD and restored de novo generation of donor pDCs in recipient mice. pDCs suppress the proliferation and expansion of activated T cells via a type-I IFN signaling-dependent mechanism. They also produce PD-L1 and LILRB4 to inhibit T cell production of IFN-. Thus, MPPs represent an effective target to bolster pDC reconstitution for GVHD prevention. In spite of these promising preliminary findings, the mechanisms by which MPPs produce pDCs and GVHD impairs MPPs after allo-HSCT in cancer patients as well as patients undergoing allo-HSCT for other diseases remain unknown. Our continuing studies suggested that Dot1l, which catalyzes H3K79 methylation, is crucial for pDC development. Dot1l appears to be critical for HSC and MPP differentiation into pDCs, PD-L1- and LILRB4-expressing pDCs (termed P/L+ pDCs) in particular. GVHD decreases Dot1l function in MPPs. Thus, impaired Dot1l activity may be the major contributor to pDC defects during GVHD. Successful harnessing of pDCs for GVHD prevention will rely on an understanding of how Dot1l regulates MPP generation, maintenance and pDC formation. We hypothesize that Dot1l promotes the generation and maintenance of MPPs and regulates pDC specification of MPPs. Alloreactive T cell responses can inhibit this Dot1l effect, inducing pDC defects and causing feed-forward GVHD exacerbation. Aim-1 will define the role of Dot1l in pDC reconstitution and the impact of GVHD on Dot1l action in HSPCs. Aim-2 will determine the molecular mechanisms through which pDCs repress alloreactive T cell responses. Aim-3 focuses on the impact of human pDCs on alloreactive T cell responses and assesses whether donor P/L+ pDCs in the allografts can be utilized to predict GVHD in cancer patients. Our proposal explores a heretofore unrecognized role of Dot1l in controlling pDC production and function. If successful, our work will open up new avenues to better understand pDC pathophysiology and translate pDC-based therapies to the clinic to help patients with hematologic malignancies and other blood diseases undergoing allo-HSCT.

主要研究者：张毅 移植物抗宿主病（GVHD）是异基因造血细胞移植后癌症患者中危及生命的并发症的原因，其导致供体浆细胞样树突状细胞（pDC）的重建失败，因为pDC对于免疫保护和耐受是至关重要的。然而，关于GVHD相关的pDC分子缺陷和供体pDC对癌症中GVHD的精确作用知之甚少。我们使用鼠和人系统来揭示GVHD诱导供体pDC缺陷的机制。GVHD耗尽维持pDC的供体多能祖细胞（MPP），导致pDC产生受损。MPP丢失与产生MPP的造血干细胞（HSC）数量减少和氧化应激诱导的剩余增殖MPP死亡相关;这与GVHD背景下常见的低血细胞计数临床观察结果相关。在我们的模型中，同种异体反应性T细胞产生GM-CSF以抑制Tcf 4的MPP表达，Tcf 4是pDC发育所必需的转录因子，破坏pDC的MPP产生。GM-CSF不影响pDC前体的成熟。值得注意的是，在同种异体HSC移植（allo-HSCT）后早期过继转移时供体pDC的恢复增强抑制了GVHD并恢复了受体小鼠中供体pDC的从头产生。pDC通过I型IFN信号传导依赖性机制抑制活化T细胞的增殖和扩增。它们还产生PD-L1和LILRB 4以抑制IFN-γ的T细胞产生。因此，MPP代表了支持pDC重建用于GVHD预防的有效靶标。尽管这些有希望的初步发现，MPP产生pDC和GVHD损害癌症患者以及因其他疾病接受allo-HSCT的患者中allo-HSCT后MPP的机制仍然未知。 我们的持续研究表明，催化H3 K79甲基化的Dot 1 l对于pDC的发育至关重要。Dot 11似乎对HSC和MPP分化为pDC，特别是表达PD-L1和LILRB 4的pDC（称为P/L+ pDC）至关重要。GVHD降低MPP中的Dot 1 l功能。因此，受损的Dot 1 l活性可能是GVHD期间pDC缺陷的主要贡献者。成功利用pDC预防GVHD将取决于对Dot 1 l如何调节MPP产生、维持和pDC形成的了解。我们假设Dot 1 l促进MPPs的产生和维持，并调节MPPs的pDC特化。同种异体反应性T细胞反应可以抑制这种Dot 1 l效应，诱导pDC缺陷并引起前馈GVHD恶化。目的-1将定义Dot 1 l在pDC重建中的作用以及GVHD对HSPC中Dot 1 l作用的影响。目的-2将确定pDCs抑制同种异体反应性T细胞应答的分子机制。目的-3关注人pDC对同种异体反应性T细胞应答的影响，并评估同种异体移植物中的供体P/L+ pDC是否可用于预测癌症患者中的GVHD。我们的提议探索了迄今为止未被认识到的Dot 1 l在控制pDC产生和功能中的作用。如果成功，我们的工作将开辟新的途径，以更好地了解pDC病理生理学，并将基于pDC的治疗转化为临床，以帮助血液恶性肿瘤和其他血液疾病患者接受allo-HSCT。