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.

pi：yi张 同种异体造血细胞移植后癌症患者威胁生命的并发症的病因，导致供体塑形树突状细胞（PDC）的重构失败，因为PDC对免疫保护和容忍至关重要，因此癌症患者的生命并发症是威胁性造血细胞移植后，癌症患者的生命并发症的病因至关重要。然而，关于GVHD相关的PDC分子缺陷以及供体PDC对GVHD在癌症中的确切影响知之甚少。我们使用鼠和人类系统来揭示GVHD诱导供体PDC缺陷的机制。 GVHD耗尽了维持PDC的供体多能祖细胞（MPP），导致PDC产生受损。 MPP丧失与增加产生MPP的造血干细胞（HSC）的数量以及氧化应激诱导的剩余MPP死亡有关；这与在GVHD的情况下对低血分计数的常见临床观察有关。在我们的模型中，同种反应性T细胞产生GM-CSF以抑制TCF4的MPP表达，TCF4是PDC发育至关重要的转录因子，颠覆了MPP的PDC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）反映GVHD并在受体小鼠中恢复了从头生成的供体PDC后，提前提高了供体PDC的回收率。 PDC通过IFN信号依赖性机制抑制活化T细胞的增殖和扩展。它们还产生PD-L1和LILRB4以抑制IFN-的T细胞产生。这是MPPS代表了加强PDC预防GVHD重建的有效目标。尽管有这些有希望的初步发现，但MPPS产生PDC和GVHD的机制会损害Allo-HSCT在癌症患者中，以及接受其他疾病的Allo-HSCT的患者仍然未知。 我们的继续研究表明，催化H3K79甲基化的DOT1L对于PDC发育至关重要。 DOT1L对于HSC和MPP分化至关重要，尤其是表达PDC和LILRB4的PDC（尤其称为P/L+ PDC）。 GVHD降低了MPP中的DOT1L函数。 DOT1L活性受损可能是GVHD期间PDC缺陷的主要因素。成功利用PDC进行GVHD预防，将依靠对DOT1L如何调节MPP生成，维护和PDC形成的理解。我们假设DOT1L促进MPP的产生和维护，并调节MPP的PDC规范。同种异体T细胞反应可以抑制这种DOT1L效应，诱导PDC缺陷并引起馈送GVHD加剧。 AIM-1将定义DOT1L在PDC重建中的作用以及GVHD对DOT1L在HSPC中的影响。 AIM-2将确定PDC通过这些分子机制反映同种异体T细胞反应。 AIM-3的重点是人类PDC对同种异体T细胞反应的影响，并评估同种异体移植物中的供体P/L+ PDC是否可以用于预测癌症患者的GVHD。我们的建议探讨了迄今为止，DOT1L在控制PDC的生产和功能中的作用。如果成功的话，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的疗法转化为诊所，以帮助血液学恶性肿瘤和其他血液疾病患者接受Allo-HSCT。