Effect of S-layer glycoprotein from potentially probiotic Lactobacillus kefiri on activation of murine macrophages in vitro

MALAMUD M; CARASI P; SERRADELL MA

CABA

Congreso; First Meeting LASID-SAI-FAIC; 2015

Sociedad Argentina de Inmunología

Surface layers are (glyco)-proteinaceous cell envelope structures ubiquitously found in different bacterial species. The subunits are attached to the underlying cell surface by non-covalent interactions, and have an intrinsic tendency to self-assembly either in solution or on solid supports. Lactobacillus kefiri is a potentially probiotic microorganism carrying a glycosylated S-layer protein which have shown interesting functional properties. The aim of this work was to assess the effect of S-layer protein from L. kefiri CIDCA8348 (SL-8348) on activation of murine macrophages in-vitro. SL-8348 was removed with 5M LiCl and exhaustively dialyzed against PBS. Raw264.7 cultures in DMEM-10% FBS were incubated with SL-8348 (10 ug/ml) or LPS (0.1 and 1 ug/ml) or SL-8348+LPS as stimuli. Activation after 48h was followed by MHC-II, CD86 and CD40 surface expression, and secretion of IL-6, IL-10 and IL-5. Quantitative PCR were performed for il-10, il-6, and tnf-a genes after the first 4h of stimulation. Cells incubated with PBS or OVA (10 ug/ml) or OVA-LPS were used as controls. Noteworthy, although SL-8348 induced only a slight activation of Raw264.7 cells, its presence enhanced macrophage´s response to both LPS stimuli. A significant increment (P