Laboratory of Pharmacology, Chulabhorn Research Institute, Bangkok, 10210, Thailand; Center of Excellence on Environmental Health and Toxicology, Bangkok, 10400, Thailand.
Center of Excellence on Environmental Health and Toxicology, Bangkok, 10400, Thailand; Graduate Program on Applied Biological Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok, 10210, Thailand; Translational Research Unit, Chulabhorn Research Institute, Bangkok, 10210, Thailand.
Eur J Pharmacol. 2021 Apr 15;897:173960. doi: 10.1016/j.ejphar.2021.173960. Epub 2021 Feb 19.
Cholangiocarcinoma (CCA) is a malignant biliary tract epithelium tumor. The programmed death-1 (PD-1)/programmed receptor-ligand 1 (PD-L1) signaling pathway has been implicated as an immune escape mechanism in several cancers. The present study aimed to assess the expression of PD-L1 on human CCA cell lines and its potential role in suppressing CD8 T- cell function. A panel of intrahepatic CCA cell lines was evaluated for immune regulatory checkpoint ligands and inflammation markers. Effects of pro-inflammatory cytokine, interferon gamma (IFN-γ), on the expression of immune regulatory checkpoint ligands and inflammation markers were determined. The PD-L1 function was measured by co-culturing CCA cells with lymphocytes. Most of the selected Thai CCA cell lines, including HuCCA-1, RMCCA-1, KKU-100, and KKU-213, expressed higher PD-L1 than normal cholangiocyte MMNK-1 and ANK-1 cells. Both PD-L1 and cyclooxygenase-2 (COX-2) expressions were highest in HuCCA-1 cells. A 48 h treatment with IFN-γ increased the expression of PD-L1 and COX-2 in CCA cells. The expression of CTLA-4 ligands, including H7-1 and H7-2, did not change after IFN-γ treatment. Rofecoxib, a specific COX-2 inhibitor, mitigated IFN-γ-induced PD-L1 expression. After 48 h co-incubation, CD8 T-cell apoptosis was increased as compared to the control group. Pretreatment of CCA cells with IFN-γ further increased CD8 T-cell apoptosis. Pembrolizumab, an anti-PD-1 antibody, mitigated CCA cell escape phenomenon. The inhibition of T-cell-mediated immune response via the PD-L1/PD-1 axis are evidenced in intrahepatic CCA. Immunotherapy with checkpoint inhibitor offers a potentially therapeutic strategy for CCA patients; however, further in vivo and clinical studies are required.
胆管癌（CCA）是一种恶性胆道上皮肿瘤。程序性死亡受体-1（PD-1）/程序性死亡配体 1（PD-L1）信号通路已被认为是多种癌症中的一种免疫逃逸机制。本研究旨在评估 PD-L1 在人类 CCA 细胞系中的表达及其对抑制 CD8 T 细胞功能的潜在作用。评估了一组肝内 CCA 细胞系的免疫调节检查点配体和炎症标志物。测定促炎细胞因子干扰素-γ（IFN-γ）对免疫调节检查点配体和炎症标志物表达的影响。通过将 CCA 细胞与淋巴细胞共培养来测量 PD-L1 的功能。在所选择的大多数泰国 CCA 细胞系中，包括 HuCCA-1、RMCCA-1、KKU-100 和 KKU-213，其 PD-L1 的表达均高于正常胆管细胞 MMNK-1 和 ANK-1 细胞。HuCCA-1 细胞中 PD-L1 和环氧化酶-2（COX-2）的表达均最高。IFN-γ 处理 48 小时可增加 CCA 细胞中 PD-L1 和 COX-2 的表达。IFN-γ 处理后 CTLA-4 配体 H7-1 和 H7-2 的表达没有改变。特异性 COX-2 抑制剂罗非昔布减轻了 IFN-γ 诱导的 PD-L1 表达。与对照组相比，共孵育 48 小时后 CD8 T 细胞凋亡增加。CCA 细胞先用 IFN-γ 预处理进一步增加 CD8 T 细胞凋亡。抗 PD-1 抗体 pembrolizumab 减轻了 CCA 细胞的逃逸现象。在肝内 CCA 中证实了通过 PD-L1/PD-1 轴抑制 T 细胞介导的免疫反应。免疫检查点抑制剂的免疫治疗为 CCA 患者提供了一种潜在的治疗策略；然而，需要进一步的体内和临床研究。
