Promoting immunity against acute myeloid leukemia through Fc effector-optimized antibody inhibitory of MICA/B shedding

通过 Fc 效应子优化抗体抑制 MICA/B 脱落，增强对急性髓系白血病的免疫力

• 批准号: 10585146
• 负责人: Lucas Ferrari de Andrade
• 金额: $ 49.28万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-06 至 2027-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10585146
• 关键词: Academia; Acute Myelocytic Leukemia; Address; Affinity; Antibodies; Antigens; Binding; Biological Assay; Biology; Blood; Bone Marrow; Bypass; CD34 gene; Cell Line; Cells; Cellular Immunity; Cellular Stress; Clinical; Clinical Trials; Collaborations; Cytotoxic T-Lymphocytes; Dichloromethylene Diphosphonate; Drug Combinations; Effector Cell; Engraftment; Epigenetic Process; Extracellular Domain; Fc Receptor; Fc domain; Goals; Grant; HDAC4 gene; Hematopoietic Neoplasms; Hematopoietic stem cells; Histone Deacetylase Inhibitor; Human; IgG1; Immune; Immunity; Immunocompetent; Immunologic Surveillance; Immunotherapeutic agent; Immunotherapy; Leukemic Cell; Lymphocyte; Macrophage; Malignant - descriptor; Malignant Neoplasms; Mediating; Membrane Proteins; Messenger RNA; Metalloproteases; Modeling; Monoclonal Antibodies; Mus; Mutation; Natural Killer Cells; Outcome; Pathway interactions; Patients; Pattern; Phagocytosis; Phagocytosis Induction; Pharmacologic Substance; Phase; Phase I Clinical Trials; Point Mutation; Post-Translational Protein Processing; Pre-Clinical Model; Protein Disulfide Isomerase; Proteins; Publishing; Regimen; Series; Signal Transduction; Solid Neoplasm; Structure; Surface; T-Lymphocyte; Testing; Time; Translating; Treatment Efficacy; Universities; acute myeloid leukemia cell; analog; antileukemic activity; cancer cell; cancer type; cytotoxic; experimental group; experimental study; human model; humanized mouse; immunogenicity; in vivo; in vivo Model; inhibiting antibody; leukemia; leukemic stem cell; mRNA Expression; monocyte; mouse model; novel; pre-clinical; protein expression; receptor; response; synergism

SUMMARY Acute myeloid leukemia (AML) is a clonal hematopoietic stem and progenitor cell malignancy characterized by poor clinical outcomes. Malignant transformation triggers expression of surface proteins that serve as “danger signals”, such as MICA and MICB (MICA/B) that are commonly expressed by leukemia cells in response to cellular stress pathways. Natural killer (NK) cells and cytotoxic T lymphocytes recognize MICA/B with the NKG2D receptor, which in turn induces cytotoxic functions against leukemia cells. However, they often escape recognition by shedding MICA/B via an intriguing post-translational modification called proteolytic cleavage. In previous and revolutionary study, we developed a series of MICA/B-targeted monoclonal antibodies that inhibit the shedding of MICA/B by blocking the extracellular domain that undergoes an unfolding by disulfide isomerase, which enables subsequent cleavage by metalloproteases. One of them was further characterized, and it promotes NK cell-mediated immunity against solid tumors by dual signaling of NKG2D and Fc receptors. Recently, we discovered that the antibody also promotes macrophage-driven immunity in AML models, by enabling antibody-dependent phagocytosis of leukemia cells in the blood and bone marrow. In this setting, MICA/B serve as “leukemia antigens” for Fc receptor-driven immunity, although contributions by NKG2D, NK cells, and T cells were also detected. Now we developed a new version of this antibody, with three point mutations in the Fc domain to increase the binding affinity to all three Fc activating receptors while maintaining low affinity to the Fc inhibitory receptor. This new version is humanized and induces potent NK cell effector functions against human AML cells, compared to the humanized wild type version. We also established mouse models of human Fc receptor biology and both murine and human AML models, to establish the anti-leukemia activity of our now enhanced molecule in vivo. Furthermore, we propose a mechanism-driven drug combination regimen, whereby a histone deacetylase inhibitor (romidepsin) induces human leukemia cells to express MICA/B mRNAs that are then translated to MICA/B proteins, which are followed by stabilization on cellular surface by our antibody that inhibits the shedding. We propose that immunotherapy for AML can be achieved via this drug combination, which increases the innate immunogenicity of leukemia cells. For these reasons, our studies will generate important information about how to induce protective immunity against AML. Antibody-mediated inhibition of MICA/B shedding is a new immunotherapeutic opportunity pioneered by us and now validated independently by multiple pharmaceutical companies, one of which has recently began phase-I clinical trial testing an antibody analog to ours, but the wild type version, in patients with advanced solid tumors. Therefore, our studies will generate compelling rationale to test MICA/B-targeted antibodies in AML trials, by pharmaceutical companies, ourselves in academia, or both by working in collaboration.

总结 急性髓系白血病（AML）是一种克隆性造血干细胞和祖细胞恶性肿瘤，其特征在于： 临床效果差。恶性转化引发表面蛋白质的表达，成为“危险” 信号”，如云母和MICB（云母/B），它们通常由白血病细胞响应于 细胞应激途径自然杀伤（NK）细胞和细胞毒性T淋巴细胞通过NKG 2D识别云母/B 受体，其反过来诱导针对白血病细胞的细胞毒性功能。然而，他们经常逃跑。 通过一个有趣的翻译后修饰，称为蛋白水解切割，脱落云母/B的识别。在 以前的革命性研究，我们开发了一系列云母/B靶向单克隆抗体，抑制 通过阻断经历二硫键异构酶解折叠的细胞外结构域而使云母/B脱落， 这使得随后能够被金属蛋白酶切割。其中一个被进一步描述，它 通过NKG 2D和Fc受体的双重信号传导促进NK细胞介导的抗实体瘤免疫。 最近，我们发现该抗体还促进AML模型中巨噬细胞驱动的免疫， 使血液和骨髓中的白血病细胞的抗体依赖性吞噬作用成为可能。在这种情况下， 云母/B作为Fc受体驱动免疫的“白血病抗原”，尽管NKG 2D、NK 细胞和T细胞也被检测到。现在我们开发了这种抗体的新版本， Fc结构域中的突变，以增加对所有三种Fc活化受体的结合亲和力，同时维持对所有三种Fc活化受体的亲和力。 对Fc抑制性受体的亲和力低。这种新版本是人源化的，并诱导有效的NK细胞效应子。 与人源化野生型版本相比，人源化野生型版本具有针对人AML细胞的功能。我们还建立了小鼠 人Fc受体生物学模型以及鼠和人AML模型，以建立抗白血病 我们现在增强的分子在体内的活性此外，我们提出了一种机制驱动的药物组合， 组蛋白脱乙酰酶抑制剂（罗米地辛）诱导人白血病细胞表达云母/B的方案 mRNA然后被翻译成云母/B蛋白，随后通过 我们的抗体可以抑制脱落我们建议通过这种药物可以实现AML的免疫治疗 组合，其增加白血病细胞的先天免疫原性。因此，我们的研究将 产生关于如何诱导针对AML的保护性免疫的重要信息。抗体介 云母/B脱落抑制是我们开创的新的免疫学机会，现在已经得到验证 由多家制药公司独立进行，其中一家最近开始了I期临床试验 在晚期实体瘤患者中测试与我们类似的抗体，但野生型版本。因此，我们认为， 我们的研究将产生令人信服的理由，以测试云母/B靶向抗体在AML试验中，由制药 公司，我们自己在学术界，或两者合作。