title: Modulation of intracellular growth of Listeria monocytogenes in human enterocyte Caco-2 cells by interferon-gamma and interleukin-6: role of nitric oxide and cooperation with antibiotics.
abstract: The influence of interferon (IFN)-gamma and interleukin (IL)-6 on the intracellular growth of Listeria monocytogenes phagocytosed from the apical pole was examined in polarized Caco-2 cells. IFN-gamma (from the apical pole) and IL-6 (from the basolateral pole) considerably reduced the bacterial intracellular growth, an effect largely abolished by l-monomethyl arginine. Both cytokines caused overexpression of inducible nitric oxide synthase. IL-6, but not IFN-gamma, caused a partial restriction of L. monocytogenes in phagosomes and largely prevented the cytosolic forms from being surrounded by actin. Ampicillin was bacteriostatic in unstimulated cells but modestly bactericidal in cells treated with IFN-gamma and IL-6. Azithromycin (a macrolide) was fairly bactericidal and sparfloxacin (a fluoroquinolone) highly bactericidal in all situations. IFN-gamma and IL-6 may therefore be important determinants in the protection of epithelial cells from intracellular multiplication of L. monocytogenes. Ampicillin may fail in their absence, requiring the use of other antibiotics such as the fluoroquinolones.
authors.affiliation: Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, UCL, B-1200 Brussels, Belgium. ouadrhiri@facm. ucl.ac.be
authors.forename: Y
authors.initials: Y
authors.lastname: Ouadrhiri
authors.forename: Y
authors.initials: Y
authors.lastname: Sibille
authors.forename: P M
authors.initials: PM
authors.lastname: Tulkens
mesh_terms: D018938:Caco-2 Cells; D016764:Cell Polarity; D020895:Enterocytes / Q000382:microbiology*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D015850:Interleukin-6 / Q000494:pharmacology*; D007700:Kinetics; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development* / Q000648:ultrastructure; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000494:pharmacology; D014162:Transfection; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D015850:Interleukin-6; D011994:Recombinant Proteins; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D007371:Interferon-gamma; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II