Modulation of Signaling Pathways by Probiotics in the Gut Mucosa

LEMME DUMIT JOSE; SAAVEDRA L; HEBERT EM; PERDIGÓN G; MALDONADO GALDEANO C

Congreso; 18th International Congress of Mucosal Immunology; 2017

Probiotic may modulate the gut immune functionsand ameliorate diseases. The aim of the current studywas to determine the signaling pathways send by twoprobiotics and their cell walls (CW), compared with anenteropathogen analyzing the regulatory genesexpression of TLRs after activation triggered bybacteria interaction with intestinal epithelial cells(IECs) and peritoneal macrophages (PMQ). BALB/cmice were given with Lactobacillus casei CRL431(Lc431) or its cell walls (CW431) and Lactobacillusparacasei CNCM I-1518 (Lp1518) or its CW1518 during7 or 5 days, respectively. After that, expressing genes(a20, irak-m, mkp-1 and tollip) were determined onIECs and PMQ by RT-qPCR. Probiotics bacteria andtheir CW were able to increase the expression ofregulator genes of TLRs pathways (a20, irak-m, mkp-1and tollip) on IECs compared to Salmonella (negativecontrol), while on PMQ showed lower expression ofregulatory genes. Considering previous study, wedemonstrated that probiotics interact with immuneand non-immune cells through TLRs (TLR2 and TLR4)and MyD88; we propose that probiotics modulate theNF-κB pathway by expression of regulators of signalingpathways on IECs. In the presence of pathogenicmicroorganisms, IECs secrete cytokines that arecrucial for the recruitment and the activation ofinflammatory cells. PMQ does not increase theexpression of regulatory genes because of these cellsare key players in the host response tomicroorganisms. We demonstrate the way by whichprobiotics are able to modulate the gut mucosalimmune system, without interfere in the activation ofthe immune cells distant to the gut.