Bifidobacteria increases uptake of latex beads by phagocytic cells.

ROLNY, I. S; ASSAD, S. E; MINNAARD, J. Y PÉREZ, P. F.

Congreso; II Congreso Brasileño de Pre, Pro y Simbióticos.; 2015

Bifidobacteria are potentially probiotic microorganisms that can lead to immunomodulatory effects on the host. Since activity of macrophages is a key component of the immune response, the aim of the present study was to gain insight on the effect of Bifidobacterium strains with different surface properties on the interaction between polystyrene beads and cultured monocytic THP-1 cells.Monocytic THP1 cells were differentiated with phorbol myristate acetate (PMA) 200 nm in DMEM 10% fetal bovine serum for 3 days at 37°C in 5% CO2 atmosphere.Latex beads carboxylate-modified polystyrene fluorescent yellow-green (2 um size) were used. B. bifidum CIDCA 5310 (hydrophobic strain) and B. adolescentis CIDCA 5317 (non-hydrophobic strain) were cultured (48h; 37°C) in MRS broth in anaerobic conditions. Heat treated (121°C- 15 min), UV treated (30 min) and untreated bacteria were suspended in DMEM and co-incubated with beads and THP1 cells at MOI (multiplicity of infection) =10 bacteria/cell for 1h at 37°C 5% CO2. Different beads/monocyte ratios (BM) were used. Association and phagocytosis were evaluated by flow cytometry by recording values of number of FL1(+) cells x mean fluorescence intensity (UI). For quenching of non-internalized bacteria trypan blue was used. In addition, confocal laser microscopy was also used to assess interaction.When viable bifidobacteria were used (MOI=10), association of beads (BM=10) with THP1 cells was similar for both strains under study, i. e. 5310 strain (UI: 3192 ± 632.22) and 5317 strain (UI: 2736 ± 412.76). These values were not significantly different from those of controls without bifidobacteria (UI: 3238 ± 379.22). In contrast, bead uptake was significantly increased (p