Zhou Ru, Mayberry Rebecca, Firmin Taina, Sanders Alexa, Brouwer Cory, Maher John, Mukherjee Pinku
Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States.
Department of Bioinformatics, University of North Carolina at Charlotte, Charlotte, NC, United States.
Front Immunol. 2025 Aug 8;16:1618415. doi: 10.3389/fimmu.2025.1618415. eCollection 2025.
Pancreatic cancer (PC) remains one of the most challenging cancers and has the worst prognosis. Tumor-associated MUC1 (tMUC1) is overexpressed and aberrantly glycosylated in over 80% of human pancreatic ductal adenocarcinoma (PDA). Chimeric antigen receptor (CAR) engineered T cells are an emerging cancer immunotherapy strategy and recently, we successfully engineered tMUC1-specific human and mouse CAR T cells and demonstrated their effectiveness as monotherapy against PDA and . In this study, we observed varying sensitivity among human PDA cell lines in response to tMUC1-targeted CAR T cell cytolysis. Notably, highly resistant HPAFII cells released greater amounts of interferon (IFN)-regulated ICAM-1, CXCL10, and CXCL11 compared to the more sensitive MiaPaCa-2 cells following CAR T cell challenge. Blocking IFN signaling using Ruxolitinib, a JAK1/2 inhibitor (JAKi), significantly reduced the upregulation of ICAM-1 and CXCL10. Western blot analysis revealed that both type I and type II IFN signaling pathways were elevated in PDA cells upon CAR T cell treatment. JAKi effectively suppressed this signaling response, with a more pronounced impact on the type I IFN pathway. Importantly, both IFN blockade and transient knockdown of IFN receptors significantly enhanced the sensitivity of PDA cells to CAR T cell-mediated cytolysis . Further mechanistic study revealed that CAR T cells partially lose their cytolytic potential after engaging with PDA cells. Treatment with CAR T cells triggered the up-regulation of immune checkpoint PD-L1 expression on PDA cells via tumor cell' own IFN signaling. Thus, blocking PD-L1 in HPAFII enhanced its response to CAR T cells. Similarly, neutralizing CXCL10 enhanced CAR T cell killing of HPAFII cells suggested CXCL10's involvement in resistance to CAR T cell cytolysis. RNA-seq data indicated higher expression of multiple genes along the IFN signaling pathway which were associated with poor prognosis in PDA patients. Taken together, tumor intrinsic IFN signaling may drive immune evasion in PDA cells against tMUC1-targeted T cell-mediated immunotherapy. This identifies tumor IFN signaling as a potential therapeutic target to improve CAR T cell efficacy in PDA treatment.
胰腺癌（PC）仍然是最具挑战性的癌症之一，预后最差。肿瘤相关MUC1（tMUC1）在超过80%的人胰腺导管腺癌（PDA）中过度表达且糖基化异常。嵌合抗原受体（CAR）工程化T细胞是一种新兴的癌症免疫治疗策略，最近，我们成功构建了tMUC1特异性的人和小鼠CAR T细胞，并证明了它们作为单一疗法对PDA的有效性。在本研究中，我们观察到人类PDA细胞系对靶向tMUC1的CAR T细胞溶解反应存在不同的敏感性。值得注意的是，与更敏感的MiaPaCa-2细胞相比，高度耐药的HPAFII细胞在CAR T细胞攻击后释放出更多的干扰素（IFN）调节的ICAM-1、CXCL10和CXCL11。使用JAK1/2抑制剂鲁索替尼（Ruxolitinib，JAKi）阻断IFN信号，显著降低了ICAM-1和CXCL10的上调。蛋白质印迹分析显示，CAR T细胞处理后，PDA细胞中的I型和II型IFN信号通路均升高。JAKi有效抑制了这种信号反应，对I型IFN通路的影响更为明显。重要的是，IFN阻断和IFN受体的瞬时敲低均显著增强了PDA细胞对CAR T细胞介导的细胞溶解的敏感性。进一步的机制研究表明，CAR T细胞与PDA细胞结合后部分丧失了细胞溶解潜能。CAR T细胞处理通过肿瘤细胞自身的IFN信号触发PDA细胞上免疫检查点PD-L1表达的上调。因此，在HPAFII中阻断PD-L1增强了其对CAR T细胞的反应。同样，中和CXCL10增强了CAR T细胞对HPAFII细胞的杀伤作用，表明CXCL10参与了对CAR T细胞溶解的抗性。RNA测序数据表明，IFN信号通路中多个基因的表达较高，这些基因与PDA患者的不良预后相关。综上所述，肿瘤内在的IFN信号可能驱动PDA细胞对靶向tMUC1的T细胞介导的免疫治疗产生免疫逃逸。这表明肿瘤IFN信号作为一个潜在的治疗靶点，可提高CAR T细胞在PDA治疗中的疗效。
