title: Cell surface-associated elongation factor Tu mediates the attachment of Lactobacillus johnsonii NCC533 (La1) to human intestinal cells and mucins.
abstract: The aim of this work was to identify Lactobacillus johnsonii NCC533 (La1) surface molecules mediating attachment to intestinal epithelial cells and mucins. Incubation of Caco-2 intestinal epithelial cells with an L. johnsonii La1 cell wall extract led to the recognition of elongation factor Tu (EF-Tu) as a novel La1 adhesin-like factor. The presence of EF-Tu at the surface of La1 was confirmed by analysis of purified outer surface protein extract by immunoblotting experiments, by electron microscopy, and by enzyme-linked immunosorbent assays of live bacteria. Furthermore, tandem mass spectrometry analysis proved that EF-TU was expressed at the La1 surface as an intact molecule. Using recombinant La1 EF-Tu protein, we were able to determine that its binding to intestinal cells and to mucins is pH dependent. Competition experiments suggested that EF-Tu has an important role in La1 mucin binding capacity. In addition, immunomodulation studies performed on HT29 cells showed that EF-Tu recombinant protein can induce a proinflammatory response in the presence of soluble CD14. Our in vitro results indicate that EF-Tu, through its binding to the intestinal mucosa, might participate in gut homeostasis.
authors.affiliation: Nestlé Research Center, CH-1000 Lausanne 26, Switzerland. dominique-anne.granato@rdls.nestle.com
authors.forename: Dominique
authors.initials: D
authors.lastname: Granato
authors.forename: Gabriela E
authors.initials: GE
authors.lastname: Bergonzelli
authors.forename: Raymond David
authors.initials: RD
authors.lastname: Pridmore
authors.forename: Laure
authors.initials: L
authors.lastname: Marvin
authors.forename: Martine
authors.initials: M
authors.lastname: Rouvet
authors.forename: Irène E
authors.initials: IE
authors.lastname: Corthésy-Theulaz
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001422:Bacterial Adhesion; D018938:Caco-2 Cells; D002460:Cell Line; D002473:Cell Wall / Q000378:metabolism*; D006801:Humans; D007249:Inflammation; D016209:Interleukin-8 / Q000378:metabolism; D007422:Intestines / Q000737:chemistry / Q000166:cytology / Q000382:microbiology*; D007778:Lactobacillus / Q000378:metabolism / Q000472:pathogenicity*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009077:Mucins / Q000378:metabolism*; D010444:Peptide Elongation Factor Tu / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D016209:Interleukin-8; D009077:Mucins; D011994:Recombinant Proteins; D010444:Peptide Elongation Factor Tu