title: Immunomodulation by Yersinia enterocolitica: comparison of live and heat-killed bacteria.
abstract: This study compared the immunomodulating properties of viable and killed Yersinia enterocolitica O9 in BALB/c mice. At 10 days after infection by the intragastric route, ex vivo assays showed a suppression of spleen cell proliferation in response to Salmonella lipopolysaccharide, concanavalin A and heat-killed yersiniae. Mice infected with Y. enterocolitica O9 for 10 days resisted the challenge with a lethal dose of Listeria monocytogenes. In contrast, intravenous administration of heat-killed yersiniae did not modify the ability of spleen cells to proliferate in response to lipopolysaccharide or concanavalin A, and proliferation in response to killed yersiniae was significantly increased. By 3 days after administration of a single dose of heat-killed yersiniae, the resistance of mice to L. monocytogenes challenge was significantly increased. Our findings show profound differences in immunomodulation by viable and heat-killed yersiniae, but suggest that killed yersiniae retain interesting immunomodulating properties.
authors.affiliation: Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain. aruizbr@ugr.es
authors.forename: Alfonso
authors.initials: A
authors.lastname: Ruiz-Bravo
authors.forename: Carmen
authors.initials: C
authors.lastname: Bujalance
authors.forename: Francisco
authors.initials: F
authors.lastname: Romero
authors.forename: Encarnacion
authors.initials: E
authors.lastname: Moreno
authors.forename: Maria
authors.initials: M
authors.lastname: Jimenez-Valera
mesh_terms: D000818:Animals; D002455:Cell Division / Q000276:immunology; D003208:Concanavalin A / Q000276:immunology; D005260:Female; D016219:Immunotherapy, Adoptive / Q000379:methods; D008070:Lipopolysaccharides / Q000276:immunology; D008089:Listeria monocytogenes / Q000276:immunology*; D008088:Listeriosis / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000166:cytology / Q000276:immunology* / Q000382:microbiology; D015009:Yersinia Infections / Q000276:immunology*; D015008:Yersinia enterocolitica / Q000276:immunology*
chemical_list: D008070:Lipopolysaccharides; D003208:Concanavalin A