Anti-inflammatory effect of bifidobacteria strains via modulation of TLR negative regulators in porcine intestinal epithelial cells

YOHSUKE TOMOSADA; JULIO VILLENA; KOZUE MORATA; ERIKO CHIBA; TOMOYUKI SHIMAZU; HISASHI ASO; NORISUKE IWABUCHI; JIN-ZHONG XIAO; TADAO SAITO; HARUKI KITAZAWA

Liepzig

Congreso; 5th Congress of European Microbiologists ? FEMS2013; 2013

European Microbiologists Societies

We have reported that evaluation of anti-inflammatory activities of lactic acid bacteria in porcine intestinal epithelial (PIE) cells is useful for selecting potentially immunobiotic strains. The aims of this study were: i) to select potentially immunobiotic bifidobacteria that beneficially regulate the Toll-like receptor (TLR)-4-triggered inflammatory response of heat-killed enterotoxigenic Escherichia coli (ETEC) in PIE cells and; ii) to elucidate the molecular mechanisms involved in the anti-inflammatory effect of immunobiotics by evaluating the role of TLR2 and TLR negative regulators in the modulation of proinflammatory cytokine production and TLR signalings in PIE cells. Bifidobacteria longum BB536 and B. breve M-16V strains significantly downregulated levels of IL-8, CCL2 and IL-6 in PIE cells challenged with ETEC. Moreover, these strains attenuated the proinflammatory response by modulating the NF-κB and MAPK pathways. In addition, our findings provide evidence for a key role for the ubiquitin-editing enzyme A20 in the anti-inflammatory effect of immunobiotic bifidobacteria in PIE cells. We show new findings regarding the mechanism involved in the anti- inflammatory effect of immunobiotics. Several strains with immunoregulatory capabilities used a common mechanism to induce tolerance in PIE cells. Immunoregulatory strains interacted with TLR2, upregulated the expression of A20 in PIE cells, and beneficially modulated the subsequent TLR4 activation by reducing the activation of MAPK and NF-κB pathways and the production of proinflammatory cytokines. We also show that the combination of TLR2 activation and A20 induction can be used as biomarkers to screen and select potential immunobiotic strains.