S-LAYER GLYCOPROTEIN FROM LACTOBACILLUS KEFIRI ENHANCED TLR-INDUCED ACTIVATION ON HUMAN MACROPHAGES THROUGH C-TYPE LECTIN RECEPTORS ENGAGEMENT

MALAMUD M; ERREA A; RUMBO M; SERRADELL MA

Mar del Plata

Congreso; Reunión Anual SAI SAIC SAFIS; 2018

Surface layers are nanostructured (glyco)-proteinaceous cell envelopes ubiquitously found in different species of Archaea and Bacteria. We have previously demonstrated that the S-layer glycoprotein from probiotic Lactobacillus kefiri CIDCA 8348 (SLP-8348) favored the LPS-induced response on murine macrophages (Raw 264.7 cells), and SLP´s glycan moieties are involved in that effect. In this work, we aim to study the ability of SLP-8348 to enhance TLR-induced response on human macrophages using different agonists as well as to investigate the involvement of the recognition by C-type lectin receptors (CLR) in that synergistic effect. SLP-8348 was removed from bacterial cells with 5 M LiCl and exhaustively dialyzed against PBS. Human macrophages (THP-1 cells) cultured in RPMI-10% FBS were incubated with SLP-8348 (10 g/ml) or TLR-agonists such as E. coli LPS, Salmonella Typhimurium flagellin (FliC) and poly-IC, or combination of SLP-8348+agonist at different concentrations. Cell activation was assessed by quantification of secreted IL-6 by ELISA after 24h of incubation. In a similar way to the previous report for murine macrophages, although SLP-8348 did not induce cell activation by itself, it favored significantly the LPS-induced activation on THP-1 cells (P