title: Listeriolysin O Affects the Permeability of Caco-2 Monolayer in a Pore-Dependent and Ca2+-Independent Manner.
abstract: Listeria monocytogenes is a food and soil-borne pathogen that secretes a pore-forming toxin listeriolysin O (LLO) as its major virulence factor. We tested the effects of LLO on an intestinal epithelial cell line Caco-2 and compared them to an unrelated pore-forming toxin equinatoxin II (EqtII). Results showed that apical application of both toxins causes a significant drop in transepithelial electrical resistance (TEER), with higher LLO concentrations or prolonged exposure time needed to achieve the same magnitude of response than with EqtII. The drop in TEER was due to pore formation and coincided with rearrangement of claudin-1 within tight junctions and associated actin cytoskeleton; however, no significant increase in permeability to fluorescein or 3 kDa FITC-dextran was observed. Influx of calcium after pore formation affected the magnitude of the drop in TEER. Both toxins exhibit similar effects on epithelium morphology and physiology. Importantly, LLO action upon the membrane is much slower and results in compromised epithelium on a longer time scale at lower concentrations than EqtII. This could favor listerial invasion in hosts resistant to E-cadherin related infection.
authors.affiliation: Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
authors.forename: Miša Mojca
authors.initials: MM
authors.lastname: Cajnko
authors.affiliation: Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
authors.forename: Maja
authors.initials: M
authors.lastname: Marušić
authors.affiliation: Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
authors.forename: Matic
authors.initials: M
authors.lastname: Kisovec
authors.affiliation: Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
authors.forename: Nejc
authors.initials: N
authors.lastname: Rojko
authors.affiliation: Laboratory for Biotechnology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
authors.forename: Mojca
authors.initials: M
authors.lastname: Benčina
authors.affiliation: Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia.
authors.forename: Simon
authors.initials: S
authors.lastname: Caserman
authors.affiliation: Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia; Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia.
authors.forename: Gregor
authors.initials: G
authors.lastname: Anderluh
mesh_terms: D000199:Actins / Q000378:metabolism; D001427:Bacterial Toxins / Q000378:metabolism*; D018938:Caco-2 Cells / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D002118:Calcium / Q000378:metabolism*; D062445:Claudin-1 / Q000378:metabolism; D003064:Cnidarian Venoms / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006460:Hemolysin Proteins / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D008089:Listeria monocytogenes / Q000502:physiology*; D008088:Listeriosis / Q000378:metabolism* / Q000473:pathology; D010539:Permeability
chemical_list: D000199:Actins; D001427:Bacterial Toxins; D062445:Claudin-1; D003064:Cnidarian Venoms; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; C012307:equinatoxin; C038705:hlyA protein, Listeria monocytogenes; D002118:Calcium