免疫疗法，包括嵌合抗原受体 (CAR) T 细胞和双特异性抗体 (BsAb)，在治疗急性髓性白血病 (AML) 时遇到了一些挑战，包括这些治疗的持久性有限、抗原丢失和白血病干细胞 (LSC) 的耐药性在这里，我们提出了一种新型双靶向方法，利用工程化抗 IL10R CAR-T 细胞分泌靶向 CD33 的双特异性抗体。这一创新策略植根于我们之前的研究，该研究建立了 IL-10 与 AML 细胞干性之间的联系，旨在提高靶向效率并根除 LSC 和 AML 母细胞。我们首先证明了这种协同方法在消除 AML 方面的卓越功效即使在 CD33 或 IL10R 表达较低的情况下，细胞系和原代细胞也表达不同水平的靶抗原。此外，分泌抗CD33 bsAb（CAR.BsAb-T）的IL10R CAR-T细胞不仅在IL10R CAR-T细胞中而且在旁观者T细胞中表现出增强的细胞毒性激活和诱导，从而更有效地靶向CD33 -阳性肿瘤细胞。我们的体内实验提供了额外的证据，表明 CAR.BsAb-T 细胞可以有效地重定向 T 细胞，减少肿瘤负荷，并且没有明显的毒性。此外，通过该策略将 bsAb 局部递送至肿瘤部位有助于减轻通常与原型 bsAb 快速清除相关的药代动力学挑战。总体而言，针对 IL10R CAR 的单载体工程设计，随后分泌 CD33 靶向的 bsAb，解决了由于 IL10R 和 CD33 的异质表达导致的免疫逃逸问题，代表着旨在改善治疗结果的 AML 治疗的一个有希望的进展。© 2024。Springer Nature Switzerland AG。

Immunotherapies, including chimeric antigen receptor (CAR) T cells and bispecific antibodies (BsAbs), encounter several challenges in the management of acute myeloid leukemia (AML), including limited persistence of these treatments, antigen loss and resistance of leukemia stem cells (LSCs) to therapy.Here, we proposed a novel dual-targeting approach utilizing engineered anti-IL10R CAR-T cells to secrete bispecific antibodies targeting CD33. This innovative strategy, rooted in our previous research which established a connection between IL-10 and the stemness of AML cells, designed to improve targeting efficiency and eradicate both LSCs and AML blasts.We first demonstrated the superior efficacy of this synergistic approach in eliminating AML cell lines and primary cells expressing different levels of the target antigens, even in cases of low CD33 or IL10R expression. Furthermore, the IL10R CAR-T cells that secret anti-CD33 bsAbs (CAR.BsAb-T), exhibited an enhanced activation and induction of cytotoxicity not only in IL10R CAR-T cells but also in bystander T cells, thereby more effectively targeting CD33-positive tumor cells. Our in vivo experiments provided additional evidence that CAR.BsAb-T cells could efficiently redirect T cells, reduce tumor burden, and demonstrate no significant toxicity. Additionally, delivering bsAbs locally to the tumor sites through this strategy helps mitigate the pharmacokinetic challenges typically associated with the rapid clearance of prototypical bsAbs.Overall, the engineering of a single-vector targeting IL10R CAR, which subsequently secretes CD33-targeted bsAb, addresses the issue of immune escape due to the heterogeneous expression of IL10R and CD33, and represents a promising progress in AML therapy aimed at improving treatment outcomes.© 2024. Springer Nature Switzerland AG.