Modulation of Signaling Pathways by Probiotics in the Gut Mucosa

LEMME DUMIT, J.M.; HEBERT, E.M.; SAAVEDRA, L.; PERDIGON, G.; MALDONADO GALEANO, C.

Congreso; ICM 2017. 18th International Congress of Mucosal Immunology. Frontiers in Mucosal Immunology and Disease; 2017

Probiotic may modulate the gut immune functions and ameliorate diseases. The aim of the current study was to determine the signaling pathways send by two probiotics and their cell walls (CW), compared with an enteropathogen analyzing the regulatory genes expression of TLRs after activation triggered by bacteria interaction with intestinal epithelial cells (IECs) and peritoneal macrophages (PMQ). BALB/c mice were given with Lactobacillus casei CRL431(Lc431) or its cell walls (CW431) and Lactobacillus paracasei CNCM I-1518 (Lp1518) or its CW1518 during or 5 days, respectively. After that, expressing genes (a20, irak-m, mkp-1 and tollip) were determined on IECs and PMQ by RT-qPCR. Probiotics bacteria and their CW were able to increase the expression of regulator genes of TLRs pathways (a20, irak-m, mkp-1 and tollip) on IECs compared to Salmonella (negative control), while on PMQ showed lower expression of regulatory genes. Considering previous study, we demonstrated that probiotics interact with immune and non-immune cells through TLRs (TLR2 and TLR4) and MyD88; we propose that probiotics modulate the NF-κB pathway by expression of regulators of signalingpathways on IECs. In the presence of pathogenic microorganisms, IECs secrete cytokines that are crucial for the recruitment and the activation of inflammatory cells. PMQ does not increase the expression of regulatory genes because of these cells are key players in the host response tomicroorganisms. We demonstrate the way by which probiotics are able to modulate the gut mucosal immune system, without interfere in the activation of the immune cells distant to the gut.