Off-the-shelf engineered NK cells for the treatment of AML

总结： 异基因造血移植（HSCT）是治疗AML的有效方法。的复发 恶性肿瘤仍然是治疗失败的主要原因， are required.自然杀伤（NK）细胞是一类独特的淋巴细胞，具有细胞毒性， 可介导针对骨髓性白血病有效抗白血病作用的免疫调节功能 同时在临床前模型中预防GVHD。相对较少的NK细胞存在于 外周血或骨髓移植细胞产物和NK细胞在移植后早期恢复 移植物具有损害细胞毒性的功能缺陷。我们已经开发了强大的临床程序 用于脐带血（CB）衍生的NK细胞的离体扩增和活化。的长期目标 这项研究是开发新的基于细胞的疗法，以利用NK细胞的抗白血病潜力。 针对AML，并通过重新定义其特异性和/或 目的1检验了添加最佳选择的离体 扩增和活化的CB源性NK细胞将改善AML患者脐带血移植后的结局。 血液移植（CBT）我们发现，HLA纯合的AML患者， C2组在CBT后复发的风险显著高于那些 HLA C1组纯合子或杂合子。从机制上讲，我们已经证明， C2/C2风险组中的疾病进展与免疫活性的延迟出现有关。 CBT后C2特异性KIR 2DL 1/S1+ NK细胞。这表明，这些患者将受益于 CBT后输注表达KIR 2DL 1/S1的活化的成熟CB-NK细胞。广泛的生物 将检查过继输注的CB-NK细胞的表型、功能和归巢，以及它们的 对移植后免疫重建的影响。目标2利用了这样的发现，即基线 NK细胞的细胞毒性可以通过表达针对NK细胞的嵌合抗原受体（CAR）来增强。 目标细胞。CD 123是白细胞介素-3受体的α链，是细胞免疫调节的一个有吸引力的靶点。 但对正常造血细胞的细胞毒性将妨碍安全递送 在没有HSCT的情况下我们将检验NK细胞用CAR转导为CD 123的假设， 共表达CD 28和IL 15以介导长期持久性，以及诱导型半胱天冬酶9（IC 9）， 管理潜在的毒性将提供针对AML的增强的活性。目标3检查是否阻塞 通过逆转录病毒转导具有显性阴性TGF-β II型的NK细胞的TGF-β途径 受体可以使NK细胞对免疫抑制性AML微环境具有抗性。最优 目标2和3中制定的战略将转化为人类临床试验， 在目标1中确定的平台协议。

Summary: Allogeneic hematopoietic transplantation (HSCT) is an effective treatment for AML. Relapse of the malignancy remains the major cause of treatment failure and improved strategies to eradicate leukemia are required. Natural killer (NK) cells are a unique class of lymphocytes, with cytotoxic, and immunoregulatory function which can mediate potent antileukemia effects against myeloid leukemias while simultaneously preventing GVHD in preclinical models. Relatively few NK cells are present in peripheral blood or bone marrow transplant cell products and the NK cells recovering early post transplant have functional defects impairing cytotoxicity. We have developed robust clinical procedures for the ex vivo expansion and activation of cord blood (CB)-derived NK cells. The long-tem objective of this research is to develop novel cell based therapies to harness the antileukemic potential of NK cells against AML, and to further enhance their effector function by both redefining their specificity and/or enhancing their potency Aim 1 tests the hypothesis that the addition of optimally selected, ex vivo expanded and activated CB-derived NK cells will improve the outcomes of patients with AML after cord blood transplantation (CBT). We have found that patients with AML whose HLA type is homozygous for group C2 have a significantly higher risk of relapse following CBT compared to those who are homozygous or heterozygous for HLA group C1. Mechanistically, we have shown that the increased risk of disease progression in the C2/C2 risk group is related to delayed emergence of immunocompetent C2-specific KIR2DL1/S1+ NK cells post-CBT. This suggests that such patients would benefit from the post-CBT infusion of activated mature CB-NK cells that express KIR2DL1/S1. Extensive biologic correlates will examine the phenotype, function and homing of adoptively infused CB-NK cells, and their impact on immune reconstitution post-transplant. Aim 2 capitalizes on the finding that the baseline cytotoxicity of NK cells can be augmented by expression of a chimeric antigen receptor (CAR) against the target cells. CD123, the α chain of the interleukin-3 receptor, is an attractive target for cellular immune therapy in AML, but cytotoxicity against normal hematopoietic cells would preclude safe delivery in the absence of HSCT. We will test the hypothesis that NK cells transduced with a CAR to CD123, and coexpressing CD28 and IL15 to mediate long term persistence, and inducible caspase 9 (IC9) to manage potential toxicity will provide enhanced activity against AML. Aim 3 examines if blocking the TGF-beta pathway by retrovirally transducing NK cells with a dominant negative TGF-beta type II receptor can render NK cells resistant to the immunosuppressive AML microenvironment. Optimal strategies formulated in aims 2 and 3 will be translated into human clinical trials, based on the optimal platform protocol determined in aim 1.