title: An in vitro cell-culture model demonstrates internalin- and hemolysin-independent translocation of Listeria monocytogenes across M cells.
abstract: An ability to translocate the mucosal epithelia through M cells provides invasive pathogens with a rapid means of accessing the mucosal lymphoid tissues. In order to determine the role of M cells in Listeria monocytogenes infection, we initially assessed colonization of Peyer's patch (PP) epithelium in BALB/c mice by Vibrio cholerae Eltor, wild-type L. monocytogenes and an isogenic hemolysin mutant (LO28Deltahly). It was observed that both wild-type L. monocytogenes and Deltahly showed preferential colonization of PP epithelium in this model. Furthermore, a novel luciferase reporter system was used to show rapid site-specific localization of L. monocytogenes in intestinal Peyer's patches. To examine the role of M cells in transcytosis of L. monocytogenes we utilized an in vitro transwell model that mimics M-cell activity through differentiation of C2Bbe1 epithelial enterocytes via co-culture with murine Peyer's patch lymphocytes (PPL). It was shown that L. monocytogenes transits M cells at significantly increased rates compared to C2Bbe1 monocultures. In addition, M-cell transport occurred independently of bacterial hemolysin and internalin production. This study demonstrates rapid transcytosis of L. monocytogenes through M cells, a process that occurs independently of the action of classical virulence factors.
authors.affiliation: Department of Microbiology and Alimentary Pharmabiotic Centre, University College Cork, Ireland.
authors.forename: Sinéad
authors.initials: S
authors.lastname: Corr
authors.forename: Colin
authors.initials: C
authors.lastname: Hill
authors.forename: Cormac G M
authors.initials: CG
authors.lastname: Gahan
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000502:physiology*; D018988:Bacterial Translocation / Q000502:physiology*; D018938:Caco-2 Cells; D002454:Cell Differentiation / Q000502:physiology; D018920:Coculture Techniques; D004269:DNA, Bacterial / Q000235:genetics; D006460:Hemolysin Proteins / Q000096:biosynthesis / Q000502:physiology*; D006801:Humans; D008089:Listeria monocytogenes / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D008088:Listeriosis / Q000378:metabolism / Q000382:microbiology*; D008565:Membrane Proteins / Q000096:biosynthesis / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D046529:Microscopy, Electron, Transmission; D016254:Mutagenesis, Insertional; D010581:Peyer's Patches / Q000378:metabolism / Q000382:microbiology*; D013047:Specific Pathogen-Free Organisms
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D006460:Hemolysin Proteins; D008565:Membrane Proteins; C095768:inlB protein, Listeria monocytogenes; C069761:internalin protein, Bacteria