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

基本信息

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
项目类别：
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

项目摘要

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：张毅移植物抗宿主病（GVHD）是癌症患者同种异体造血细胞移植后出现危及生命的并发症的一个原因，它会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至关重要。关于 GVHD 相关的 pDC 分子缺陷以及供体 pDC 对癌症 GVHD 的精确影响知之甚少。 GVHD 诱导供体 pDC 缺陷的机制是，GVHD 耗尽了维持 pDC 的供体多能祖细胞 (MPP)，导致 pDC 生成受损，与产生 MPP 的造血干细胞 (HSC) 数量减少和氧化应激诱导的死亡有关。剩余增殖的 MPP 的数量；这与 GVHD 情况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，产生同种反应性 T 细胞。 GM-CSF 抑制 Tcf4（pDC 发育所必需的转录因子）的 MPP 表达，破坏 pDC 的 MPP 产生，但不会影响 pDC 前体的成熟。值得注意的是，同种异体 HSC 后早期过继转移时供体 pDC 的恢复得到增强。移植（allo-HSCT）可抑制 GVHD 并恢复受体小鼠中供体 pDC 的从头生成，通过 I 型 IFN 抑制活化 T 细胞的增殖和扩增。它们还产生 PD-L1 和 LILRB4 来抑制 T 细胞产生 IFN-α，因此，MPP 是促进 pDC 重建以预防 GVHD 的有效靶标。 MPPs 产生 pDCs，而 GVHD 在癌症患者以及因其他疾病接受 allo-HSCT 后对 MPPs 的损害仍不清楚。我们的持续研究表明，催化 H3K79 甲基化的 Dot1l 对于 pDC 发育至关重要，尤其是对于 HSC 和 MPP 分化为 pDC，尤其是表达 PD-L1 和 LILRB4 的 pDC（称为 P/L+ pDC）。 GVHD 降低 MPP 中的 Dot1l 功能，因此，受损的 Dot1l 活性可能是 pDC 缺陷的主要原因。 GVHD 的成功利用 pDC 预防 GVHD 将依赖于对 Dot1l 如何调节 MPP 生成、维持和 pDC 形成的理解。这种 Dot1l 效应，诱导 pDC 缺陷并导致前馈 GVHD 恶化，Aim-1 将定义 Dot1l 在 pDC 中的作用。 Aim-2 的重建和 GVHD 对 HSPC 中 Dot1l 作用的影响将确定 pDC 抑制同种异体反应性 T 细胞反应的分子机制，Aim-3 重点关注人类 pDC 对同种异体反应性 T 细胞反应的影响，并评估供体 P/ 是否。同种异体移植物中的 L+ pDC 可用于预测癌症患者的 GVHD。我们的建议探索了 Dot1l 在控制方面迄今为止未被认识的作用。如果成功，我们的工作将为更好地了解 pDC 病理生理学开辟新途径，并将基于 pDC 的疗法转化为临床，以帮助患有血液恶性肿瘤和其他血液疾病的患者接受异基因造血干细胞移植。