title: Capacity of ivanolysin O to replace listeriolysin O in phagosomal escape and in vivo survival of Listeria monocytogenes.
abstract: Listeriolysin O (LLO, hly-encoded) is a major virulence factor secreted by the pathogen Listeria monocytogenes. The amino acid sequence of LLO shows a high degree of similarity with that of ivanolysin O (ILO), the cytolysin secreted by the ruminant pathogen Listeria ivanovii. Here, it was tested whether ILO could functionally replace LLO by expressing the gene encoding ILO under the control of the hly promoter, in an hly-deleted strain of L. monocytogenes. It is shown that ILO allows efficient phagosomal escape of L. monocytogenes in both macrophages and hepatocytes. Moreover, expression of ILO is not cytotoxic and promotes normal intracellular multiplication. In vivo, the ILO-expressing strain can multiply and persist for several days in the liver of infected mice but is unable to survive in the spleen. This work underscores the key role played by the cytolysin in the virulence of pathogenic Listeria.
authors.affiliation: Laboratoire de Microbiologie, INSERM U-570, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Frehel
authors.affiliation: Laboratoire de Microbiologie, INSERM U-570, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
authors.forename: Marie-Annick
authors.initials: MA
authors.lastname: Lety
authors.affiliation: Laboratoire de Microbiologie, INSERM U-570, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Autret
authors.affiliation: Laboratoire de Microbiologie, INSERM U-570, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Beretti
authors.affiliation: Laboratoire de Microbiologie, INSERM U-570, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Berche
authors.affiliation: Laboratoire de Microbiologie, INSERM U-570, Faculté de Médecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Charbit
mesh_terms: D000818:Animals; D001427:Bacterial Toxins; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006460:Hemolysin Proteins; D006461:Hemolysis; D006801:Humans; D008089:Listeria monocytogenes / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity*; D008088:Listeriosis / Q000382:microbiology; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D010588:Phagosomes / Q000382:microbiology*; D014407:Tumor Cells, Cultured; D014774:Virulence
chemical_list: D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; C038705:hlyA protein, Listeria monocytogenes