EVALUATION OF THE EFFECT OF PROBIOTIC BACTERIA ON THE IMUNE RESPONSE TO A.ACTINOMYCETEMCOMITANS: A STUDY IN GINGIVAL EPITHELIAL CELLS AND IN EXPERIMENTAL MODEL OF INFECTION IN VIVO.

Abstract

The project aims to test the hypothesis that probiotic microorganisms or their products are able to control periodontitis induced by Aggregatibacter actinomycetemcomitans (Aa) by regulating the immune response to this pathogen. Initial results indicate that probiotics L.rhamnosus Lr32 and HN001 and L. acidophilus NCFM and La5 interfere with fimbria mediated biofilm formation of A. actinomycetemcomitans. In addition, probiotic lactobacilli and bifidobacteria are capable of altering the cytokine profile produced by epithelial cells and macrophages after challenge with P. gingivalis and E. coli LPS, and to reduce the adhesion and invasion of P. gingivalis in gingival epithelial cells, indicating its potential in modulating inflammation. Aggressive periodontitis is associated with a complex microbiota, including A. actinomycetemcomitans. The present proposal aims to determine the ability of probiotic strains to modulate the immune response against Aa in in vitro and animal models. Gingival epithelial cells (OBA-9 strain) will be used and the effect of probiotics on the pathogen's adhesion and invasion capacity, cytokine profile, expression of genes associated with the inflammatory process and activation of signaling pathways will be evaluated. Probiotic strains will be tested in an animal model inoculated with A. actinomycetemcomitans in normal and diabetic rats. With the strategies employed, we hope to select probiotic strain (s) capable of interfering with Aa colonization and induce a response capable of altering the oral and gut microbiota favoring the health-associated microbiota in equilibrium with the host.