title: Expression of listeriolysin O by intracellular Listeria monocytogenes following infection of lipopolysaccharide-treated or untreated J774.1 macrophage-like cells.
abstract: Listeria monocytogenes replicates in a phagocytic cell following escape into the host cytoplasm. Listeriolysin O, secreted by L. monocytogenes, which belongs to the thiol-activated hemolysin family, is known to play an important role in the escape of the bacterium into the host cytoplasm. In this study, we demonstrated that expression of listeriolysin O by infecting L. monocytogenes was lightly induced in J774.1 macrophage-like cells pretreated with lipopolysaccharide, although the growth of the bacteria was suppressed. The number of viable L. monocytogenes decreased until 4 h post-infection and then increased between 4 and 8 h post-infection in untreated J774.1 host cells, but it decreased until 8 h post-infection in lipopolysaccharide-treated host cells. However, expression of listeriolysin O by L. monocytogenes was not induced in the untreated host cells, while it increased 0 and 4 h post-infection in the lipopolysaccharide-treated host cells. Expression of listeriolysin O mRNA in the lipopolysaccharide-like cells. These results suggest that macrophage activation induced with lipopolysaccharide could lead to the expression of the listeriolysin O gene and the synthesis of listeriolysin O protein under suppression of the intracellular growth of L. monocytogenes.
authors.affiliation: Department of Veterinary Science, National Institute of Health, Tokyo, Japan. kohji@nih.go.jp
authors.forename: K
authors.initials: K
authors.lastname: Moriishi
authors.forename: M
authors.initials: M
authors.lastname: Koura
authors.forename: F
authors.initials: F
authors.lastname: Amano
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D001427:Bacterial Toxins; D002451:Cell Compartmentation; D003593:Cytoplasm / Q000382:microbiology; D015870:Gene Expression; D005822:Genetic Vectors; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D006460:Hemolysin Proteins / Q000096:biosynthesis* / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D008262:Macrophage Activation; D008264:Macrophages / Q000187:drug effects / Q000382:microbiology*; D010588:Phagosomes / Q000382:microbiology; D012329:RNA, Bacterial / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D008070:Lipopolysaccharides; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011994:Recombinant Proteins; C038705:hlyA protein, Listeria monocytogenes