20.500.12556/DiRROS-24363 Targeting cystatin F activation enhances NK cell cytotoxicity in glioblastoma models Introduction: Glioblastoma (GBM) is a highly invasive brain tumor with limited treatment options and poor prognosis. Natural killer (NK) cells are key effectors of antitumor immunity, capable of eliminating cancer stem-like cells. However, GBM creates an immunosuppressive microenvironment that limits NK cell function. Here, we identify cystatin F as an immunosuppressive factor involved in regulating NK cell granule-mediated cytotoxicity. Methods: We analyzed cystatin F expression in GBM and its correlation with immune exhaustion markers. NK cell activity was compared between GBM patients and healthy donors. In vitro co-cultures of cystatin F-expressing microglial cells and glioblastoma stem-like cells were used to assess NK cell function. To block cystatin F activation from dimeric to active monomeric form, a small-molecule inhibitor of cathepsin V, the activating protease, was applied. Results: Cystatin F expression correlated with immune exhaustion and suppression markers in GBM. NK cells from patients showed reduced cytotoxicity compared to healthy donors. Co-cultures confirmed that cystatin F-expressing microglia impaired NK cell cytotoxicity, while inhibition of cathepsin V restored NK cell function in standard cytotoxicity assays, 3D spheroids, and microfluidic perfused models. Discussion: These results indicate that cystatin F mediates NK cell suppression in GBM. Targeting its activation enhances NK cell cytotoxicity, offering a potential strategy to improve NK-based immunotherapy for glioblastoma. glioblastoma cystatin F 3D models glioblastom cistatin F 3D-modeli true false true Angleški jezik Slovenski jezik Neznano 2025-11-26 09:56:19 2025-11-26 09:56:19 2025-11-27 03:58:54 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Soavtorji iz Slovenije: Anamarija Habič, Urban Švajger, Ana Mitrović, Matic Proj, Andrej Porčnik, Borut Prestor, Miha Jerala, Matic Bošnjak, Stanislav Gobec, Barbara Breznik, Janko Kos, Milica Perišić Nanut; Opis vira z dne 21. 11. 2025; str. 1-14 Vol. 16, [art. no.] 1708281 Oct. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2025-10-28 577 1664-3224 10.3389/fimmu.2025.1708281 258230275 https://doi.org/10.3389/fimmu.2025.1708281 1 cc2a162a-caa5-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36260 RAZ_Senjor_Emanuela_2025.pdf RAZ_Senjor_Emanuela_2025.pdf 1 890A2A7EC5AB96611751D25EAA2CE722 75608728198c32560e43cd1eaa5dd3260a871e5f0f28a7954b14cf1f657d8819 f955e9ec-caa5-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=36261 Nacionalni inštitut za biologijo 0 0 0