Gal-3 and neuraminidase activity are required to induce phagoptosis of neurons by Brucella abortus-activated microglia

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

Mar del Plata

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

SAI/SAIC/SAFIS

B. abortus-activated microglia kill neurons through primary phagocytosis or phagoptosis. Phagocytosis is a finely regulated process by the interaction of different receptors and their ligands. Galectin-3 (Gal-3) is a protein secreted by activated macrophages and works as opsonin through MERTK receptor. Gal-3 binds to desialylated proteins presents in the cells surface through the action of neuraminidases. Then, the objective of this work was to investigate if Gal-3 is involved in the phagoptosis of neurons mediated by B. abortus-activated microglia. Primary cultures of neurons and microglia from mice (Balb/c or C57/B6) wild type or deficient for the gal-3 gene were infected. Neuron survival at 48 h was assessed by fluorescence microscopy. The cocultures were treated with: Oserltamivir (neuraminidase inhibitor), Tacrolimus (inhibitor of the phosphorylation and subsequent secretion of Gal-3). Neuraminidase (Neu) activity in the cell membrane and TNF-a secretion were measured using commercial kits. B. abortus-infected microglia exhibit Neu activity in their cell membrane, which is inhibited by Oseltamivir (p