Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA.
Center for Biostatistics, The Ohio State University, Columbus, Ohio, USA.
Cytotherapy. 2020 Jul;22(7):369-376. doi: 10.1016/j.jcyt.2020.02.001. Epub 2020 Apr 15.
Qualitative and quantitative defects in natural killer (NK) cells have been noted in patients with acute myeloid leukemia (AML), providing rationale for infusion of donor-derived NK cells. We previously showed that decitabine enhances expression of NKG2D ligands in AML with additive cytotoxicity when NK cells and Fc (fragment crystallizable region)-engineered CD33 monoclonal antibody (CD33mAb) was used. We conducted a phase 1 study evaluating decitabine and haploidentical NK cells in relapsed AML. Using patient samples from this study, we evaluated whether ex vivo donor-derived expanded NK cells with or without CD33mAb was effective in decitabine-treated AML.
Bone marrow aspirates were collected from patients at pre- and post-NK cell infusion. NK cells from healthy donors were expanded for 14 days using irradiated K562 feeder cells displaying membrane-bound IL-21 (mbIL-21). Patient samples were used to test in vitro activity of mbIL-21 NK cells ± CD33m Ab-dependent cellular cytotoxicity (ADCC) and AML patient derived xenograft (PDX) mice were developed to test in vivo activity.
Upon incubation with primary AML blasts, mbIL-21 NK cells showed variable donor-dependent intra-cellular interferon-γ production, which increased with CD33mAb-coated AML. ADCC assays revealed mbIL-21 NK cells effectively lysed primary AML blasts with higher activity on CD33mAb-coated AML. Importantly, CD33mAb-dependent enhanced cytotoxicity by mbIL-21 NK cells was maintained in AML cells from patients even 24 days post-decitabine treatment. In vivo infusion of mbIL-21 NK cells in AML PDX mice, treated with CD33mAb, reduced the tumor burden.
These data show the therapeutic utility of mbIL-21 NK cells that can be further potentiated by addition of CD33mAb in AML.
自然杀伤 (NK) 细胞的定性和定量缺陷已在急性髓系白血病 (AML) 患者中得到证实，这为输注供体来源的 NK 细胞提供了依据。我们之前的研究表明，地西他滨可增强 AML 中 NKG2D 配体的表达，与 NK 细胞和 Fc（片段结晶区）工程化 CD33 单克隆抗体 (CD33mAb) 联合使用时具有附加的细胞毒性。我们进行了一项 1 期研究，评估了复发 AML 患者中地西他滨和单倍体 NK 细胞的情况。使用该研究中的患者样本，我们评估了是否在接受地西他滨治疗的 AML 中，添加 CD33mAb 的体外扩增供体来源 NK 细胞具有治疗效果。
在 NK 细胞输注前和输注后采集患者的骨髓抽吸物。用辐照 K562 饲养细胞（表达膜结合 IL-21 [mbIL-21]）体外扩增健康供者的 NK 细胞 14 天。使用患者样本测试 mbIL-21 NK 细胞的体外活性，± CD33mAb 依赖性细胞毒性 (ADCC)，并开发 AML 患者来源异种移植 (PDX) 小鼠来测试体内活性。
与原发性 AML blasts 孵育后，mbIL-21 NK 细胞显示出与供体依赖性的可变细胞内干扰素-γ产生，与 CD33mAb 包被的 AML 一起增加。ADCC 检测表明 mbIL-21 NK 细胞可有效裂解原发性 AML blasts，对 CD33mAb 包被的 AML 具有更高的活性。重要的是，即使在接受地西他滨治疗 24 天后，mbIL-21 NK 细胞对 CD33mAb 依赖性增强的细胞毒性在 AML 患者的细胞中仍能保持。在 AML PDX 小鼠中，在 CD33mAb 处理的基础上输注 mbIL-21 NK 细胞，可减少肿瘤负担。
这些数据表明，mbIL-21 NK 细胞具有治疗效用，在 AML 中添加 CD33mAb 可进一步增强其作用。
