Production of Reactive Oxigen Species by intestinal epithelial cells triggered by interaction with probiotic microorganisms

ROMANIN, D; GONZALEZ MACIEL, D; HIRIART, Y; GARROTE, G; RUMBO, M

Buenos Aires

Congreso; 1st French-Argentine Congress of Immunology; 2010

Sociedad Argentina de Inmunología -

Different probiotic microorganisms may modulate intestinal immune response, however the mechanisms involved remain poorly characterized. Modulation of intestinal epithelial response may contribute to probiotic function. Different intracellular signaling pathways have been shown to be modulated by epithelial-microorganism interaction. Differential targeting to the proteasome of key players of inflammatory pathways such as IkBa protein can be modulated by probiotic bacteria by a mechanism dependent on the production of Reactive Oxygen Species (ROS). The aim of the present work was to set up a system to study this phenomena on intestinal epithelial cells and test the effect on this pathway by a panel of probiotic bacteria and yeast. We standardized a procedure using Caco-2 human intestinal epithelial cell line, a ROS-indicator dye (C-H2DCFDA) and physiologic inducers of ROS production on Caco-2 cells to quantify the ROS production by fluorescence microscopy. We used this system to test a panel of 20 strains from genus Lactococcus, Enterococcus and Lactobacillus and yeasts from genus Saccharomyces and Kluyveromyces on the induction of ROS. The capacity of these microorganisms to down-regulate the expression of CCL20 was evaluated using a reporter CCL20-luc Caco-2 cell line and flagellin stimulation. Some of the bacterial strains as Lactobacillus brevis ATCC 8287 and Enterococcus faecalis induced a significant two-fold production of endogenous ROS. Although yeast strains did not induce ROS response, they reduced more than 90% the flagellin-induced CCL20 response. A system to evaluate the capacity of microorganisms to trigger ROS production in intestinal epithelial cells was developed. No correlation was observed between the capacity to modulate CCL20 response and ROS production, indicating that other mechanisms triggered by microorganism-epithelial interaction may control this innate activation of epithelial cells.