Center for Stem Cell and Regenerative Medicine, Department of Basic Medical Sciences, and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
Liangzhu Laboratory, Zhejiang University, Hangzhou, Zhejiang, 311121, China.
Nat Commun. 2023 Sep 18;14(1):5778. doi: 10.1038/s41467-023-41470-9.
The pro-inflammatory state of macrophages, underpinned by their metabolic condition, is essentially affecting their capacity of combating tumor cells. Here we find, via a pooled metabolic gene knockout CRISPR screen that KEAP1 and ACOD1 are strong regulators of the pro-inflammatory state in macrophages. We show that ACOD1 knockout macrophages, generated in our induced pluripotent stem cell-derived CAR-macrophage (CAR-iMAC) platform, are strongly and persistently polarized toward the pro-inflammatory state, which manifests in increased reactive oxygen species (ROS) production, more potent phagocytosis and enhanced cytotoxic functions against cancer cells in vitro. In ovarian or pancreatic cancer mouse models, ACOD1-depleted CAR-iMACs exhibit enhanced capacity in repressing tumors, leading to increased survival. In addition, combining ACOD1-depleted CAR-iMACs with immune checkpoint inhibitors (ICI), such as anti-CD47 or anti-PD1 antibodies, result in even stronger tumor suppressing effect. Mechanistically, the depletion of ACOD1 reduces levels of the immuno-metabolite itaconate, allowing KEAP1 to prevent NRF2 from entering the nucleus to activate an anti-inflammatory program. This study thus lays down the proof of principle for targeting ACOD1 in myeloid cells for cancer immunotherapy and introduces metabolically engineered human iPSC-derived CAR-iMACs cells with enhanced polarization and anti-tumor functions in adoptive cell transfer therapies.
巨噬细胞的促炎状态，由其代谢状态决定，本质上影响其对抗肿瘤细胞的能力。在这里，我们通过汇集代谢基因敲除 CRISPR 筛选发现，KEAP1 和 ACOD1 是巨噬细胞促炎状态的强有力调节剂。我们表明，在我们的诱导多能干细胞衍生的 CAR-巨噬细胞 (CAR-iMAC) 平台中生成的 ACOD1 敲除巨噬细胞强烈且持续地向促炎状态极化，表现为活性氧 (ROS) 产生增加、吞噬作用增强和体外对癌细胞的细胞毒性功能增强。在卵巢或胰腺癌细胞小鼠模型中，耗尽 ACOD1 的 CAR-iMAC 具有增强抑制肿瘤的能力，从而提高存活率。此外，将耗尽 ACOD1 的 CAR-iMAC 与免疫检查点抑制剂 (ICI)（如抗 CD47 或抗 PD1 抗体）联合使用，可产生更强的抑制肿瘤作用。从机制上讲，ACOD1 的耗竭降低了免疫代谢物衣康酸的水平，使 KEAP1 能够阻止 NRF2 进入细胞核激活抗炎程序。因此，这项研究为针对髓细胞中的 ACOD1 进行癌症免疫治疗奠定了原理基础，并引入了代谢工程化的人 iPSC 衍生的 CAR-iMAC 细胞，在过继细胞转移治疗中具有增强的极化和抗肿瘤功能。
