急性髓系白血病（AML）是一种以造血干细胞和祖细胞（HSPC）异常分化为特征的恶性肿瘤。虽然嵌合抗原受体 T (CAR-T) 细胞免疫疗法以 AML 细胞为目标，但它们通常通过攻击表达相同抗原的正常细胞来诱导严重的靶向/脱瘤毒性。在这里，我们使用碱基编辑器 (BE) 和初等编辑器 (PE) 来修饰 HSPC 上 CD123 的表位，保护健康细胞免受 CAR-T 诱导的细胞毒性，同时保持其正常功能。尽管BE可以有效地编辑表位，但复杂的旁观者产物是一个问题。为了提高精度，我们优化了 Prime 编辑，将 HSPC 中的编辑效率从 5.9% 提高到 78.9%。表位修饰的细胞能够抵抗 CAR-T 裂解，同时保留正常的分化和功能。此外，注入人源化小鼠体内的 BE 或 PE 编辑的 HSPC 赋予骨髓谱系对 CAR-T 免疫疗法的选择性抗性，证明了治疗复发性 AML 的概念验证策略。版权所有 © 2024 Elsevier Inc. 保留所有权利。

Acute myeloid leukemia (AML) is a malignant cancer characterized by abnormal differentiation of hematopoietic stem and progenitor cells (HSPCs). While chimeric antigen receptor T (CAR-T) cell immunotherapies target AML cells, they often induce severe on-target/off-tumor toxicity by attacking normal cells expressing the same antigen. Here, we used base editors (BEs) and a prime editor (PE) to modify the epitope of CD123 on HSPCs, protecting healthy cells from CAR-T-induced cytotoxicity while maintaining their normal function. Although BE effectively edits epitopes, complex bystander products are a concern. To enhance precision, we optimized prime editing, increasing the editing efficiency from 5.9% to 78.9% in HSPCs. Epitope-modified cells were resistant to CAR-T lysis while retaining normal differentiation and function. Furthermore, BE- or PE-edited HSPCs infused into humanized mice endowed myeloid lineages with selective resistance to CAR-T immunotherapy, demonstrating a proof-of-concept strategy for treating relapsed AML.Copyright © 2024 Elsevier Inc. All rights reserved.