Advanced application of bovine intestinal epithelial cell line for evaluating regulatory effect of lactobacilli against heat-killed enterotoxigenic Escherichia coli-mediated inflammation

作者：Takanashi Naoya; Tomosada Yohsuke; Villena Julio; Murata Kozue; Takahashi Takuya; Chiba Eriko; Tohno Masanori; Shimazu Tomoyuki; Aso Hisashi; Suda Yoshihito; Ikegami Shuji; Itoh Hiroyuki; Kawai Yasushi; Saito Tadao; Alvarez Susana; Kitazawa Haruki^*

来源：BMC Microbiology, 2013, 13(1): 54.

DOI：10.1186/1471-2180-13-54

• Bovine intestinal epithelial cells
• Immunobiotic
• ETEC PAMPs
• TLRs negative regulators
• Lactobacillus casei OLL2768

Background: Previously, a bovine intestinal epithelial cell line (BIE cells) was successfully established. This work hypothesized that BIE cells are useful in vitro model system for the study of interactions of microbial-or pathogen-associated molecular patterns (MAMPs or PAMPs) with bovine intestinal epithelial cells and for the selection of immunoregulatory lactic acid bacteria (LAB).
Results: All toll-like receptor (TLR) genes were expressed in BIE cells, being TLR4 one of the most strongly expressed. We demonstrated that heat-stable PAMPs of enterotoxigenic Escherichia coli (ETEC) significantly enhanced the production of IL-6, IL-8, IL-1 alpha and MCP-1 in BIE cells by activating both NF-kappa B and MAPK pathways. We evaluated the capacity of several lactobacilli strains to modulate heat-stable ETEC PAMPs-mediated inflammatory response in BIE cells. Among these strains evaluated, Lactobacillus casei OLL2768 attenuated heat-stable ETEC PAMPs-induced pro-inflammatory response by inhibiting NF-kappa B and p38 signaling pathways in BIE cells. Moreover, L. casei OLL2768 negatively regulated TLR4 signaling in BIE cells by up-regulating Toll interacting protein (Tollip) and B-cell lymphoma 3-encoded protein (Bcl-3).
Conclusions: BIE cells are suitable for the selection of immunoregulatory LAB and for studying the mechanisms involved in the protective activity of immunobiotics against pathogen-induced inflammatory damage. In addition, we showed that L. casei OLL2768 functionally modulate the bovine intestinal epithelium by attenuating heat-stable ETEC PAMPs-induced inflammation. Therefore L. casei OLL2768 is a good candidate for in vivo studying the protective effect of LAB against intestinal inflammatory damage induced by ETEC infection or heat-stable ETEC PAMPs challenge in the bovine host.

• 出版日期2013-3-7