부산대학교 도서관

Pancreatic cancer (PC) develops resistance to current therapeutic approaches with a consequent dismal prognosis. Immunotherapy is an effective approach in several tumors, but PC is resistant to immunotherapy. Tumor-derived extracellular vesicles (EVs) may modulate immune responses by either dampening or inducing antitumor immune responses. In this study, we explored the immunomodulatory potential of pancreatic-cancer-derived extracellular vesicles through proteomic and functional approaches. Notably, proteins involved in the “Immune System” were highly enriched in the protein cargo of PC-derived EVs, which also included immunostimulatory proteins. Interestingly, the treatment of healthy donor-derived peripheral blood mononuclear cells (PBMCs) with EVs from one of the PC cell lines analyzed induced early activation markers in CD8+ and CD4+ lymphocytes. This was consistent with the proteomic and ELISA analyses. Our study indicates that even if PC is an immune-cold tumor, in some cases, PC-EVs may activate early immune responses. This finding might be relevant for the development of effective immunotherapeutic strategies in PC. Pancreatic cancer (PC) has a poor prognosis and displays resistance to immunotherapy. A better understanding of tumor-derived extracellular vesicle (EV) effects on immune responses might contribute to improved immunotherapy. EVs derived from Capan-2 and BxPC-3 PC cells isolated by ultracentrifugation were characterized by atomic force microscopy, Western blot (WB), nanoparticle tracking analysis, and label-free proteomics. Fresh PBMCs from healthy donors were treated with PC- or control-derived heterologous EVs, followed by flow cytometry analysis of CD8+ and CD4+ lymphocytes. The proteomics of lymphocytes sorted from EV-treated or untreated PBMCs was performed, and the IFN-γ concentration was measured by ELISA. Notably, most of the proteins identified in Capan-2 and BxPC-3 EVs by the proteomic analysis were connected in a single functional network (p = 1 × 10[sup.−16]) and were involved in the “Immune System” (FDR: 1.10 × 10[sup.−24] and 3.69 × 10[sup.−19], respectively). Interestingly, the treatment of healthy donor-derived PBMCs with Capan-2 EVs but not with BxPC-3 EVs or heterologous control EVs induced early activation of CD8+ and CD4+ lymphocytes. The proteomics of lymphocytes sorted from EV-treated PBMCs was consistent with their activation by Capan-2 EVs, indicating IFN-γ among the major upstream regulators, as confirmed by ELISA. The proteomic and functional analyses indicate that PC-EVs have pleiotropic effects, and some may activate early immune responses, which might be relevant for the development of highly needed immunotherapeutic strategies in this immune-cold tumor.
Author(s): Anna Piro [1]; Maria Concetta Cufaro [2,3]; Paola Lanuti [2,3]; Davide Brocco [4]; Laura De Lellis [1]; Rosalba Florio [1]; Serena Pilato [1,5]; Sara Pagotto [2,4]; Simone De Fabritiis [...]