This study aimed to assess the effectiveness of inhibiting cholesterol acyltransferase 1 (ACAT-1) in chimeric antigen receptor T (CAR-T) cells on potentiating the antitumor response against mesothelin (MSLN)-expressing pancreatic carcinoma (PC) cells. We engineered ACAT-1-inhibited CAR-T cells (CAR-T-1847 and CAR-T-1848) using the targeting MSLN CAR lentiviral vector and small interfering RNA (siRNA) targeting the conserved region of the ACAT-1 gene, and characterized the efficacy of these modified CAR-T cells in terms of the cytotoxicity and cytokine release of both MSLN-positive and MSLN-negative PC cells using in vitro methods and in vivo mouse xenografts. The ACAT-1-inhibited CAR-T-1847 and CAR-T-1848 cells showed a higher cytotoxicity at effector-to-target cell (E:T) ratios of 8:1 and 10:1, respectively, and induced a higher secretion of proinflammatory cytokines interleukin-2 (IL-2) and interferon-gamma (IFNγ) in vitro. In addition, bioluminescence imaging of tumor xenografts of ACAT-1-inhibited targeting MSLN CAR-T cells in MSLN-positive PC mice in vivo showed significant tumor regression, which is consistent with the in vitro observations. Our findings demonstrate a novel immunotherapeutic strategy involving the transplantation of ACAT-1-inhibited targeting MSLN CAR-T cells and the feasibility of enhancing the antitumor potency of CAR-T through the novel strategy.

本研究旨在评估抑制嵌合抗原受体 T (CAR-T) 细胞中胆固醇酰基转移酶 1 (ACAT-1) 对增强针对表达间皮素 (MSLN) 的胰腺癌细胞 (PC) 细胞的抗肿瘤反应的有效性。我们使用靶向 MSLN CAR 慢病毒载体和靶向 ACAT-1 基因保守区域的小干扰 RNA (siRNA) 设计了​​ACAT-1抑制的 CAR-T 细胞（CAR-T-1847 和 CAR-T-1848），并且使用体外方法和体内方法表征这些修饰的 CAR-T 细胞在 MSLN 阳性和 MSLN 阴性 PC 细胞的细胞毒性和细胞因子释放方面的功效小鼠异种移植物。ACAT-1 抑制的 CAR-T-1847 和 CAR-T-1848 细胞在效应细胞与靶细胞 (E:T) 的比例分别为 8:1 和 10:1 时表现出更高的细胞毒性，并诱导更高的促炎细胞因子白细胞介素 2 (IL-2) 和干扰素-γ (IFNγ)在体外的分泌。此外，MSLN 阳性 PC 小鼠体内 ACAT-1 抑制靶向 MSLN CAR-T 细胞的肿瘤异种移植物的生物发光成像显示显着的肿瘤消退，这与体外观察结果一致。我们的研究结果证明了一种新的免疫治疗策略，涉及移植 ACAT-1 抑制靶向 MSLN CAR-T 细胞，以及通过新策略增强 CAR-T 抗肿瘤效力的可行性。