Dysregulation of Innate Lymphoid Immunity in Acute Myeloid Leukemia

项目摘要 我们的提案研究了急性髓细胞白血病（AML）先天免疫功能障碍的潜在机制， 在美国，白血病相关死亡的主要原因是先天免疫系统自然防御 然而，AML逃避免疫监视以驱动疾病进展。自然杀伤（NK）细胞 主要负责抗肿瘤免疫监视的先天性淋巴样细胞（ILC）和减少的NK细胞 在初发AML和移植后环境中的功能与不良结局相关。我们有 最近发现，AML患者在NK细胞发育中存在根本性缺陷，导致特定的 在协调先天性和适应性免疫中起关键作用的NK细胞亚群的耗竭 反应，以及成熟NK细胞的发育和功能。 我们已经证明NK细胞是从一种常见的先天淋巴样细胞前体（ILCP）发展而来的，ILCP产生 一系列NK发育中间体（NKDI），导致成熟的细胞毒性NK细胞。ILCP还产生 ILC家族的其他成员，一组不同的非细胞毒性的、产生精氨酸的“辅助”ILC， 已知是促肿瘤发生的。我们的初步研究表明，AML破坏了NK细胞系， 生产辅助ILC。由于这些人群都来自ILCP，这表明AML是作用于 ILCP改变谱系命运规范。血统规范通过仔细控制的活动发生， 修饰表观基因组景观的转录因子，产生稳定的细胞类型特异性基因表达 模式.我们的初步研究已经发现了一个异常的，辅助ILC样DNA甲基化特征， 从AML患者中分离的NKDI和白血病细胞共培养后的NKDI。一个关键的转录因子是芳基 碳氢化合物受体（AHR），我们发现在AHR配体存在下，它改变了辅助ILC/NK比率 由AML细胞产生的异位。我们提出了一种策略，其中AHR抑制和 低甲基化剂（HMA）指导开发以从ILCP恢复NK细胞分化。 在本提案中，我们将确定AML如何驱动这一命运决定并促进辅助ILC的生成 通过对从正常供体和AML中分离的ILCP进行详细的表观遗传和功能分析， 患者，包括在免疫活性鼠AML模型中的研究。我们将调查功能和 谱系命运的表观遗传平衡，包括AHR的作用。其次，我们将确定 AML患者NK细胞缺陷对表观遗传编程和疾病进展的影响，并直接检验 关于ILCP和NKDI开发的HMA。我们还将确定临床前疗效结合HMA 和一种新的AHR抑制剂，以恢复正常的NK细胞表观遗传编程并增强NK细胞生成， 改善AML临床前模型的结果。维持功能成熟的NK细胞并支持 免疫监视对长期疾病控制至关重要，这些研究旨在获得对 AML如何逃避先天免疫，并研究恢复抗肿瘤免疫监视患者的策略。

PROJECT SUMMARY Our proposal investigates a mechanism underlying innate immune dysfunction in acute myeloid leukemia (AML), the leading cause of leukemia-related deaths in the U.S. The innate immune system naturally defends against malignancy, however AML evades immunosurveillance to drive disease progression. Natural killer (NK) cells are the primarily innate lymphoid cell (ILC) responsible for anti-tumor immune surveillance, and reduced NK cell function both in de novo AML and in the post-transplant setting is correlated with poor outcomes. We have recently discovered that AML patients carry a fundamental defect in NK cell development leading to specific depletion of a sub-population of NK cells with critical roles in coordinating innate and adaptive immune responses, as well as mature NK cell development and function. We have shown that NK cells develop from a common innate lymphoid cell precursor (ILCP), which generates a series of NK developmental intermediates (NKDIs) leading to mature, cytotoxic NK cells. ILCPs also give rise to the other members of the ILC family, a diverse group of non-cytotoxic, cytokine-producing “helper” ILCs that are known to be pro-tumorigenic. Our preliminary studies show that AML disrupts the NK lineage, shifting production towards helper ILCs. As these populations all stem from the ILCP, this suggests AML is acting on ILCPs to alter lineage fate specification. Lineage specification occurs through carefully controlled activities of transcription factors that modify the epigenomic landscape generating stable cell type-specific gene expression patterns. Our preliminary studies have uncovered an aberrant, helper ILC-like DNA methylation signature in NKDIs isolated from AML patients and following leukemic cell co-culture. One key transcription factor is the aryl hydrocarbon receptor (AHR), which we have found shifts the helper ILC/NK ratio in the presence of AHR ligands ectopic produced by AML cells. We propose a strategy where the combination of AHR inhibition and hypomethylating agents (HMAs) guides development to restore NK cell differentiation from the ILCP. In this proposal, we will determine how AML drives this fate decision and promotes the generation of helper ILCs by performing detailed epigenetic and functional analyses of ILCPs isolated from normal donors and AML patients, including investigation in an immunocompetent murine AML model. We will investigate functional and epigenetic poising of lineage fate including the role of AHR. Secondly, we will determine the relationship of the NK cell defect in AML patients to epigenetic programming and disease progression, and directly test the impact of HMAs on ILCP and NKDI development. We will also determine the preclinical efficacy of combining both HMA and a novel AHR inhibitor to restore normal NK cell epigenetic programming and enhance NK cell generation to improve outcomes in preclinical models of AML. Maintaining functionally mature NK cells and supporting immunosurveillance is critical to long-term disease control, these studies aim to gain a novel understanding of how AML evades innate immunity and investigate strategies to restore anti-tumor immune surveillance patients.