Chimeric antigen receptor (CAR)-T cells are genetically engineered T cells, directed against a tumor-associated antigen. Extracellular vesicles (EVs) derived from CAR-T cells (CAR-T EVs) may preserve CAR-T activity and overcome one of the major obstacles responsible for CAR-T cell failure in patients with solid tumors. This study aimed to compare CAR-T EVs with their parental cells and explore their cell penetration and cytotoxic activity. Anti-HER-2 CARs were stimulated with specific target cells. EVs were isolated from the cell media and characterized for their content and functions. We found that CAR-T EVs contained a mixture of small and large EVs. Stimulated anti-HER-2⁺ CAR-T EVs expressed lower cytokine levels compared with their parental CAR-T cells (such as interferon gamma). Higher levels of granzyme B were found in CAR-T EVs (≥20 × ) compared with EVs from unstimulated cells (p < 0.001). Anti-HER-2⁺ CAR-T EVs bound and penetrated specifically into HER-2 expressing target cells. Similar cytotoxic effects measured by caspase-3/7 activity were found in CAR-T cells and their derived EVs. However, while the CAR-T cells induced massive apoptosis during the first 24 h, CAR-T EVs required 60 − 90 h. In summary, CAR-T EVs provide a novel potent immunotherapy approach that may be effective against solid tumors.

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源自嵌合抗原受体-T 细胞的细胞外囊泡：一种潜在的癌症治疗方法

嵌合抗原受体 (CAR)-T 细胞是针对肿瘤相关抗原的基因工程 T 细胞。源自 CAR-T 细胞 (CAR-T EV) 的细胞外囊泡 (EV) 可以保持 CAR-T 活性并克服导致实体瘤患者 CAR-T 细胞衰竭的主要障碍之一。本研究旨在将 CAR-T EV 与其亲代细胞进行比较，并探索其细胞穿透和细胞毒活性。用特定的靶细胞刺激抗 HER-2 CAR。EV 是从细胞培养基中分离出来的，并对其内容和功能进行了表征。我们发现 CAR-T 电动汽车包含小型和大型电动汽车的混合物。受激抗HER-2 ⁺与亲代 CAR-T 细胞（如干扰素 γ）相比，CAR-T EV 表达的细胞因子水平较低。与来自未刺激细胞的 EV 相比，在 CAR-T EV (≥20 × ) 中发现了更高水平的颗粒酶 B ( p  < 0.001)。抗 HER-2 ⁺ CAR-T EV 结合并特异性渗透到表达 HER-2 的靶细胞中。在 CAR-T 细胞及其衍生的 EV 中发现了通过 caspase-3/7 活性测量的类似细胞毒性作用。然而，虽然 CAR-T 细胞在前 24 小时内诱导了大量细胞凋亡，但 CAR-T EV 需要 60-90 小时。总之，CAR-T EVs 提供了一种新的有效免疫治疗方法，可能对实体瘤有效。