胰管腺癌（PDAC）是一种具有毁灭性的恶性肿瘤，诊断后5年生存率仅为6％，需要新型治疗方法。蛋白酶激活受体1（PAR1）在肿瘤细胞和肿瘤微环境（TME）中的多种基质细胞亚群中高度过表达，因此提供了一个适合的免疫治疗靶点。本研究采用嵌合抗原受体（CAR）策略，使用人源抗PAR1单链抗体，将其与两个共刺激性细胞内信号传导域（CD28和CD137）以及CD3ζ的内源性膜质区融合。工程化的PAR1CAR-T细胞在体外抑制了PAR1过表达和转化生长因子（TGF）-β介导的PAR1上调的肿瘤细胞，抑制率约为80％。PAR1CAR-T细胞的输注持续增强并通过80％以上的方式诱导了已建立的MIA PaCa-2癌细胞的特异性回归，此外，CAR-T细胞治疗小鼠的血清中发现了前炎细胞因子/趋化因子的增加，肿瘤中Ki67的表达减少。此外，定向消除PAR1表达的肿瘤还降低了基质金属蛋白酶1（MMP1）的水平，提示PAR1/MMP1通路的阻断构成了PDAC治疗的新选项。三代PAR1CAR-T细胞在TME中表现出抗肿瘤活性，为PDAC提供了创新的CAR-T细胞免疫治疗方法。 © 2023. BioMed Central Ltd., part of Springer Nature.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignancy with a 5-year survival rate of 6% following a diagnosis, and novel therapeutic modalities are needed. Protease-activated receptor 1 (PAR1) is abundantly overexpressed by both tumor cells and multiple stroma cell subsets in the tumor microenvironment (TME), thereby offering a suitable immunotherapy target.A chimeric antigen receptor (CAR) strategy was applied to target PAR1 using a human anti-PAR1 scFv antibody fused to the transmembrane region with two co-stimulatory intracellular signaling domains of cluster of differentiation 28 (CD28) and CD137 (4-1BB), added to CD3ζ in tandem.The engineered PAR1CAR-T cells eliminated PAR1 overexpression and transforming growth factor (TGF)-β-mediated PAR1-upregulated cancer cells by approximately 80% in vitro. The adoptive transfer of PAR1CAR-T cells was persistently enhanced and induced the specific regression of established MIA PaCa-2 cancer cells by > 80% in xenograft models. Accordingly, proinflammatory cytokines/chemokines increased in CAR-T-cell-treated mouse sera, whereas Ki67 expression in tumors decreased. Furthermore, the targeted elimination of PAR1-expressing tumors reduced matrix metalloproteinase 1 (MMP1) levels, suggesting that the blocking of the PAR1/MMP1 pathway constitutes a new therapeutic option for PDAC treatment.Third-generation PAR1CAR-T cells have antitumor activity in the TME, providing innovative CAR-T-cell immunotherapy against PDAC.© 2023. BioMed Central Ltd., part of Springer Nature.