PHOSPHATIDYL-INOSITOL-3 KINASE INHIBITORS SELECTIVELY MODULATE TLR2 LIGAND-INDUCED PRO-INFLAMMATORY MOLECULES PRODUCTION IN MICROGLIAL CELLS.

MANZONE RODRIGUEZ, CLARISA; NATALIA SOLEDAD BÁEZ; DANIELA SOLEDAD ARROYO; PABLO IRIBARREN; CECILIA MARÍA RODRÍGUEZ

San Miguel deTucumán

Congreso; LXVII Reunión Anual de la Sociedad Argentina de Inmunología,; 2019

Sociedad Argentina de Inmunología

Introduction: Microglial cells are phagocytes in the central nervous system (CNS) that become activated in pathological conditions and determine the fate of other neural cells. Control of microglial cell activation is crucial for the regulation of the inflammatory responses and host defense in the CNS. We previously reported that Toll-like receptor 2 (TLR2) stimulation by peptidoglycan (PGN) from Staphylococcus aureus, induced microglial cell activation followed by autophagy induction. In addition, our findings suggest that activation of autophagy in microglial cells modulates inflammatory responses in these cells.Methods: The murine microglial cell line BV2 was stimulated with PGN at different time points after pre-incubation in the presence or the absence of phosphatidyl-inositol-3 kinase (PI3K) inhibitors (LY294002 and 3-MA). After treatment, microglial cells were processed to evaluate: 1) cytokine production by ELISA; 2) nitric oxide (NO) production; 3) autophagy activation using LC3-II detection by western blot. All experiments were performed 3 times and p < 0.05 was considered to be statistically significant.Results: We observed that activation of microglial cells with PGN and other TLR2 ligands induced increased production of TNF, IL-1, and NO (p < 0.001). Interestingly, treatment with PI3K inhibitors prevented the increased production of both, IL-1 and NO (p < 0.001). However, these inhibitors failed to modulate TNF production (ns). In addition, 3-MA blocked PGN-induced autophagic flux in microglial cells (p < 0.001).Conclusions: These preliminary results suggest that inhibition of PI3K signaling and potentially autophagy, may selectively modulate TLR2-induced IL-1 and NO production in microglial cells.