Autophagy alters the composition of pancreatic exosomes and modulates the antitumoral activity of NK cells

GARCIA MARÍA NOÉ; ELIDA ALVAREZ; DANIELA L. PAPADEMETRIO; DANIEL GRASSO; ESTEFANIA S. PAPARATTO

CABA

Workshop; International Society for Extracellular Vesicles 2020 Workshop: EVs in Immunology; 2020

International Society for Extracellular Vesicles

Autophagy alters the composition of pancreatic exosomes and modulates the antitumoral activity of NK cellsDaniela L. Papademetrio (1,2); María Noé García (2); Estefanía S. Paparatto (1); Daniel H. Grasso (2); Élida Álvarez (1,2)1.Universidad de Buenos Aires. facultad de farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología, Cátedra de Inmunología, Buenos Aires, Argentina. 2.Universidad de Buenos Aires, CONICET, Instituto de Estudios de la Inmunidad Humoral (IDEHU), Buenos Aires, Argentina.Pancreatic ductal adenocarcinoma (PDAC) induces immunotolerance where exosomes are intercellular messengers, carrying molecules from tumor to immune cells. We previously described that autophagy is crucial for PDAC survival to gemcitabine. We investigated the role of autophagy in tumor-derived exosomes composition and their impact on Natural Killer cells (NK) activity. Exosomes were collected from supernatants of MIAPaCa-2 (EXOM-Basal) and PANC-1 (EXOP-Basal) treated with IFNβ and Spautin-1 (SP-1) as autophagy inhibitor and gemcitabine (Gem), IFNα2b and starvation (St) as autophagy inducers during 2, 6 and 24h. NK cells from Buffy-Coats of healthy donors (Ethical statement CEIC-Res#677-19) were purified by magnetic MAbs negative selection. NK cytotoxicity was evaluated by CFSE/PI stain on K562 cells. We incubated NK cells with exosomes during 2h. CFSE dyed-K562 cells were added in ratio 5:1 (NK:K562) for 4h. IFNγ release was evaluated in supernatants of cytotoxicity assays by ELISA. EXOM/P-Gem slightly increased NK cytotoxicity (19% and 21%, respectively (p