Ex Vivo PD-L1/PD-1 Pathway Blockade Reverses Dysfunction of Circulating CEA-Specific T Cells in Pancreatic Cancer Patients.
Ex Vivo PD-L1/PD-1 Pathway Blockade Reverses Dysfunction of Circulating CEA-Specific T Cells in Pancreatic Cancer Patients.
复制标题
DOI：
10.1158/1078-0432.ccr-17-1185
复制
发表时间：
2017-10-15
期刊：
影响因子：
--
通讯作者：
Morris EC
中科院分区：
文献类型：
--
作者：
Chen Y;Xue SA;Behboudi S;Mohammad GH;Pereira SP;Morris EC
癌胚抗原（CEA）是胰腺癌（PC）细胞免疫治疗的候选靶点。在这项研究中，我们表征了从 PC 患者的外周 T 细胞库中分离出的 HLA-A2 限制性肽 pCEA691-699 特异性的自体细胞毒性 T 淋巴细胞 (CTL) 的抗原特异性功能，并试图确定离体 PD-L1 和 TIM3 阻断是否可以增强 CTL 功能。 CD8+ T 细胞系由 18 名 HLA-A2+ PC 患者和 15 名健康对照者的外周血单核细胞 (PBMC) 产生。细胞内细胞因子产生染色后通过流式细胞术评估体外肽特异性反应，并使用胰腺癌细胞系作为靶标进行 CSFE 细胞毒性测定。从 18 名 PC 患者中的 10 名成功生成了分泌细胞因子的功能性 CEA691 特异性 CTL 系，其中两种 CTL 系能够识别并杀死负载 CEA691 肽的 T2 细胞和 CEA+ HLA-A2+ 胰腺癌细胞系。在存在离体 PD-L1 阻断的情况下，功能性 CEA691 特异性 CD8+ T 细胞反应（包括 IFN-γ 分泌和增殖）增强，并且这种效应对于从肿瘤引流淋巴结分离的 Ag 特异性 T 细胞更为明显。这些数据表明，CEA691 特异性 CTL 可以很容易地从 PC 患者的自我限制性 T 细胞库中扩展出来，并且它们的功能可以通过 PD-L1 阻断来增强。
Carcinoembryonic antigen (CEA) is a candidate target for cellular immunotherapy of pancreatic cancer (PC). In this study, we have characterised the antigen-specific function of autologous cytotoxic T lymphocytes (CTL) specific for the HLA-A2 restricted peptide, pCEA691–699, isolated from the peripheral T cell repertoire of PC patients and sought to determine if ex vivo PD-L1 & TIM3 blockade could enhance CTL function. CD8+ T cell lines were generated from peripheral blood mononuclear cells (PBMCs) of 18 HLA-A2+ patients with PC and from 15 healthy controls. In vitro peptide specific responses were evaluated by flow cytometry after staining for intracellular cytokine production and CSFE cytotoxicity assays using pancreatic cancer cell lines as targets. Cytokine secreting functional CEA691-specific CTL lines were successfully generated from 10 of 18PC patients, with two CTL lines able to recognise and kill both CEA691 peptide-loaded T2 cells and CEA+ HLA-A2+ pancreatic cancer cell lines. In the presence of ex vivo PD-L1 blockade, functional CEA691-specific CD8+ T cell responses, including IFN-γ secretion and proliferation, were enhanced and this effect was more pronounced on Ag-specific T cells isolated from tumor draining lymph nodes. These data demonstrate that CEA691-specific CTL can be readily expanded from the self-restricted T cell repertoire of PC patients and that their function can be enhanced by PD-L1 blockade.