AUTOCRINE AND PARACRINE IL-6 IS NECESSARY TO INDUCE PHAGOCYTOSIS OF VIABLE NEURONS BY BRUCELLA ABORTUS-ACTIVATED MICROGLIA

JULIA RODRIGUEZ; JULIA DE SANTIS AREVALO; ARIADNA FIORILLO; ANA M. RODRÍGUEZ; GIAMBARTOLOMEI, GUILLERMO H

Mar del Plata

Congreso; Congreso Anual de SAIC-SAI-SAFIS-FAIC; 2022

SAI/SAIC/SAFIS

Central nervous system infection by bacteria of the genus Brucella results in an inflammatory disorder called neurobrucellosis. We have previously demonstrated that soluble mediators released by B. abortus-infected astrocytes induce inflammatory activation of microglia and phagocytosis of viable neurons. We have also demonstrated that neutralization of IL-6 in neurons/microglia co-cultures treated with supernatants from B. abortus-infected astrocytes inhibits neuronal death, and this effect is caused by a decrease in the phagocytic activity of microglia. Considering that both astrocytes and microglia are capable of secrete IL-6, we aimed to investigate the contribution of each cell type in this phenomenon. Astrocytes from wild type (WT) and IL-6 KO mice were infected or not with B. abortus for 24 h. After that, cell-free culture supernatants were used to stimulate primary murine co-cultures of WT and IL-6 KO microglia with neurons during 48 h. Neuronal density was evaluated by fluorescence microscopy. Treatment of WT co-cultures with supernatants from IL-6 KO infected astrocytes caused a partial inhibition of neuronal death (p