Autophagy modates the immune response of pancreatic tumor cells by conditioning the exosome composition

DANIELA L. PAPADEMETRIO; NADIA PAGLILLIA; ESTEFANIA S. PAPARATTO; DANIEL GRASSO; MARIA NOÉ GARCIA; ELIDA ALVAREZ

Mar del Plata

Congreso; SAIC . SAFE . SAB . SAP 2019; 2019

Sociedad Argentina de Investigación Clínica (SAIC)

Pancreatic ductal adenocarcinoma (PDAC) is characterized by inducing immunotolerance, where exosomes act as intercellular messengers, carrying molecules from the tumor cells to the immune cells. In this work we investigated the role of autophagy in the composition of tumor-derived exosomes and their impact on the activity of Dendritic (DC) and Natural Killer cells (NK).For the experiments we used two PDAC cell lines, MIAPaCa-2 and PANC-1, and two inhibitors of autophagy, 3-Methyladenine (3-MA) and Spautin-1 (SP-1). First, we demonstrated the presence of exosomes in culture cells supernatants with or without 3-MA or SP-1 by electron microscopy. Interestingly, both treatments also increased the exosomal marker CD63 observed by WB. Afterward, Monocyte-Derived-Dendritic-Cells (MDDC) were treated with the different populations of exosomes and after 1h LPS. Cytokine production by ELISA was evaluated in 48h supernatant. MDDCs incubated with exosomes from cell culture without SP-1 secreted TGF-β, meanwhile the exosomes from cells with SP-1 induced the secretion of IL-12, and increment in HLA-DR expression on MDDC membrane (observed by flow Cytometry) (p