Immunotherapy in pancreatic ductal adenocarcinoma (PDAC) treatment faces serious challenges, due particularly to the poor immunogenicity. Cancer cell-derived small extracellular vesicles (sEVs) play important roles in damaging the immune system. However, the effects of pancreatic cancer-derived sEVs on T lymphocytes are unknown. Here we investigated changes in phenotypes and signal transduction pathways in sEVs-treated T lymphocytes. We identified the overexpression of immune checkpoint proteins PD-1, PD-L1, CTLA4, and Tim-3 and the enrichment of FOXP3+ Treg cluster in sEVs-treated T lymphocytes by CyTOF. Gene set enrichment analysis revealed that DNA damage response and metabolic pathways might be involved in sEVs-induced Tregs. ATM, AMPK, SIRT1, SIRT2, and SIRT6 were activated sequentially in sEVs-treated T lymphocytes and essential for sEVs-upregulated expressions of FOXO1A, FOXO3A, and FOXP3. Our study reveals the impact and mechanism of pancreatic cancer cell-derived sEVs on T lymphocytes and may provide insights into developing immunotherapy strategies for PDAC treatment.

胰腺导管腺癌（PDAC）治疗中的免疫疗法面临严峻挑战，特别是由于免疫原性差。癌细胞衍生的小细胞外囊泡（sEVs）在破坏免疫系统中起重要作用。但是，胰腺癌来源的sEV对T淋巴细胞的作用尚不清楚。在这里，我们研究了经sEVs处理的T淋巴细胞的表型和信号转导途径的变化。我们确定了免疫检查点蛋白PD-1，PD-L1，CTLA4和Tim-3的过度表达，以及通过CyTOF在sEVs处理的T淋巴细胞中富集了FOXP3 + Treg簇。基因集富集分析表明，DNA损伤反应和代谢途径可能与sEVs诱导的Tregs有关。ATM，AMPK，SIRT1，SIRT2，SIRT6和SIRT6在sEVs处理的T淋巴细胞中被顺序激活，对于sEVs上调FOXO1A，FOXO3A和FOXP3的表达至关重要。我们的研究揭示了胰腺癌细胞衍生的sEVs对T淋巴细胞的影响和机制，并可能为开发用于PDAC治疗的免疫疗法策略提供见识。