title: The novel porcine Lactobacillus sobrius strain protects intestinal cells from enterotoxigenic Escherichia coli K88 infection and prevents membrane barrier damage.
abstract: Lactobacilli have a potential to overcome intestinal disorders; however, the exact mode of action is still largely unknown. In this study, we have used the intestinal porcine intestinal IPEC-1 epithelial cells as a model to investigate a possible protective activity of a new Lactobacillus species, the L. sobrius DSM 16698(T), against intestinal injury induced by enterotoxigenic Escherichia coli (ETEC) K88 infection and the underlying mechanisms. Treatment of infected cells with L. sobrius strongly reduced the pathogen adhesion. L. sobrius was also able to prevent the ETEC-induced membrane damage by inhibiting delocalization of zonula occludens (ZO)-1, reduction of occludin amount, rearrangement of F-actin, and dephosphorylation of occludin caused by ETEC. RT-PCR and ELISA experiments showed that L. sobrius counteracted the ETEC-induced increase of IL-8 and upregulated the IL-10 expression. The involvement of IL-8 in the deleterious effects of ETEC was proven by neutralization of IL-8 with a specific antibody. A crucial role of IL-10 was indicated by blockage of IL-10 production with neutralizing anti-IL-10 antibody that fully abrogated the L. sobrius protection. L. sobrius was also able to inhibit the internalization of ETEC, which was likely favored by the leaking barrier. The protective effects were not found with L. amylovorus DSM 20531(T) treatment, a strain derived from cattle waste but phylogenetically closely related to L. sobrius. Together, the data indicate that L. sobrius exerts protection against the harmful effects of ETEC by different mechanisms, including pathogen adhesion inhibition and maintenance of membrane barrier integrity through IL-10 regulation.
authors.affiliation: Istituto Nazionale di Ricerca per gli Alimenti e la Nutrizione, 00178 Rome, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Roselli
authors.forename: Alberto
authors.initials: A
authors.lastname: Finamore
authors.forename: Maria Serena
authors.initials: MS
authors.lastname: Britti
authors.forename: Sergey R
authors.initials: SR
authors.lastname: Konstantinov
authors.forename: Hauke
authors.initials: H
authors.lastname: Smidt
authors.forename: Willem M
authors.initials: WM
authors.lastname: de Vos
authors.forename: Elena
authors.initials: E
authors.lastname: Mengheri
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D002460:Cell Line; D002462:Cell Membrane; D054307:Enterotoxigenic Escherichia coli / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology / Q000382:microbiology*; D004927:Escherichia coli Infections / Q000382:microbiology*; D007375:Interleukin-1 / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D007778:Lactobacillus / Q000145:classification* / Q000502:physiology*; D008565:Membrane Proteins / Q000378:metabolism; D062793:Occludin; D010750:Phosphoproteins / Q000378:metabolism; D015398:Signal Transduction; D013552:Swine / Q000382:microbiology; D062826:Zonula Occludens-1 Protein
chemical_list: D007375:Interleukin-1; D008565:Membrane Proteins; D062793:Occludin; D010750:Phosphoproteins; D062826:Zonula Occludens-1 Protein; D016753:Interleukin-10