Autophagy modulates cytokine production in microglial cells

BUSSI CLAUDIO; ARROYO DANIELA S; PERALTA-RAMOS JAVIER M; GAVIGLIO EMILIA A; IRIBARREN PABLO

Mar del Plata

Congreso; LXII Reunión Anual de la Sociedad Argentina de Inmunología; 2014

Sociedad Argentina de Inmunología

Introduction: Autophagy is an essential, homeostatic process by which cells deliver their cytoplasmic material, including soluble macromolecules and organelles, to lysosomes for degradation. Recent developments reveal a crucial role for the autophagy pathway and proteins in immunity and inflammation. They balance the beneficial and detrimental effects of immunity and inflammation, and thereby may protect against infectious, autoimmune and inflammatory diseases. Purpose: The aim of this study was to evaluate the modulatory effect of autophagy on the cytokine production in BV2 microglial cells. Experimental procedure: BV2 microglial cells were stimulated with TLRs ligands, such as PGN, Pam3 and LPS. Autophagy was induced before or after TLR stimulation by rapamycin or trehalose. Cytokines were determined in cell-free culture supernatants by ELISA. Autophagy pathway was blocked using 3-Methyladenine (3-MA), an inhibitor of type III Phosphatidylinositol 3-kinases (PI-3K). Results: Our preliminary results show that stimulation of autophagic pathway downregulates the production of the cytokines IL1b, IL-6, IL-10 and TNFa (p<0,01). This effect was inhibited when cells were pre-treated with 3-MA (p<0,01). Interestingly, when 3-MA was added to cell cultures before TLR stimulation, an increase in the release of pro-inflammatory cytokines was observed compared with TLR stimulation alone (p<0,01). However, no changes were detected in IL-10 determination. Conclusions: The induction of autophagy negatively affected the cytokine release by microglial cells. In addition, the inhibition of PI-3K showed a synergistic effect with TLR stimulation in the release of pro-inflammatory cytokines. These results suggest that the class III PI-3K pathway plays an important role in modulating inflammatory mediators. Additional studies are needed to better understand the molecular mechanisms that mediate this process.