Combining natural killer (NK) cell adoptive transfer with hypomethylating agents (HMAs) is an attractive therapeutic approach for patients with acute myeloid leukemia (AML). However, data regarding the impact of HMAs on NK cell functionality are mostly derived from in vitro studies with high nonclinical relevant drug concentrations. In the present study, we report a comparative study of azacitidine (AZA) and decitabine (DAC) in combination with allogeneic NK cells generated from CD34+ hematopoietic stem and progenitor cells (HSPC-NK cells) in in vitro and in vivo AML models. In vitro, low-dose HMAs did not impair viability of HSPC-NK cells. Furthermore, low-dose DAC preserved HSPC-NK killing, proliferation, and interferon gamma production capacity, whereas AZA diminished their proliferation and reactivity. Importantly, we showed HMAs and HSPC-NK cells could potently work together to target AML cell lines and patient AML blasts. In vivo, both agents exerted a significant delay in AML progression in NOD/SCID/IL2Rgnull mice, but the persistence of adoptively transferred HSPC-NK cells was not affected. Infused NK cells showed sustained expression of most activating receptors, upregulated NKp44 expression, and remarkable killer cell immunoglobulin-like receptor acquisition. Most importantly, only DAC potentiated HSPC-NK cell anti-leukemic activity in vivo. Besides upregulation of NKG2D- and DNAM-1-activating ligands on AML cells, DAC enhanced messenger RNA expression of inflammatory cytokines, perforin, and TRAIL by HSPC-NK cells. In addition, treatment resulted in increased numbers of HSPC-NK cells in the bone marrow compartment, suggesting that DAC could positively modulate NK cell activity, trafficking, and tumor targeting. These data provide a rationale to explore combination therapy of adoptive HSPC-NK cells and DAC in patients with AML.

中文翻译：

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地西他滨增强 NOD/SCID/IL2Rgnull 小鼠中 CD34+祖细胞衍生的 NK 细胞对 AML 细胞的靶向

将自然杀伤 (NK) 细胞过继转移与低甲基化剂 (HMA) 相结合是对急性髓系白血病 (AML) 患者有吸引力的治疗方法。然而，关于 HMAs 对 NK 细胞功能影响的数据主要来自具有高非临床相关药物浓度的体外研究。在本研究中，我们报告了阿扎胞苷 (AZA) 和地西他滨 (DAC) 与 CD34+ 造血干细胞和祖细胞 (HSPC-NK 细胞) 产生的同种异体 NK 细胞在体外和体内 AML 模型中的比较研究。在体外，低剂量 HMAs 不会损害 HSPC-NK 细胞的活力。此外，低剂量 DAC 保留了 HSPC-NK 杀伤、增殖和干扰素 γ 生产能力，而 AZA 降低了它们的增殖和反应性。重要的，我们展示了 HMAs 和 HSPC-NK 细胞可以有效地协同作用，以靶向 AML 细胞系和患者 AML 原始细胞。在体内，这两种药物都显着延迟了 NOD/SCID/IL2Rgnull 小鼠的 AML 进展，但过继转移的 HSPC-NK 细胞的持久性不受影响。注入的 NK 细胞显示出大多数激活受体的持续表达、NKp44 表达上调和显着的杀伤细胞免疫球蛋白样受体获得。最重要的是，只有 DAC 才能增强体内 HSPC-NK 细胞的抗白血病活性。除了上调 AML 细胞上的 NKG2D 和 DNAM-1 激活配体外，DAC 还增强了 HSPC-NK 细胞的炎性细胞因子、穿孔素和 TRAIL 的信使 RNA 表达。此外，治疗导致骨髓隔室中 HSPC-NK 细胞的数量增加，表明 DAC 可以积极调节 NK 细胞活性、运输和肿瘤靶向。这些数据为探索过继性 HSPC-NK 细胞和 DAC 联合治疗 AML 患者提供了依据。