title: Monoassociation with probiotic Lactobacillus delbrueckii UFV-H2b20 stimulates the immune system and protects germfree mice against Listeria monocytogenes infection.
abstract: In the present study, we investigated the protective effects of Lactobacillus delbrueckii UFV-H2b20 on the resistance to Listeria monocytogenes infection in gnotobiotic mice. Germfree mice or monoassociated mice were infected with L. monocytogenes, and the microbiological and immunological responses were evaluated after 1, 3, and 5 days of infection. Monoassociation with L. delbrueckii was capable of protecting mice against death caused by L. monocytogenes and induced a faster clearance of the bacteria in the liver, spleen, and peritoneal cavity at days 1, 3, and 5 post-infection. Also, monoassociated mice displayed less liver injury than germfree mice. The production of TNF-α in the serum, peritoneal cavity, and gut was augmented in monoassociated mice. Likewise, the levels of IFN-γ found on supernatants of spleen cells cultures were higher after the monoassociation. In addition, increased production of nitric oxide in peritoneal cell cultures supernatants and in serum was observed in mice that received L. delbrueckii. The monoassociation with L. delbrueckii induced higher production of IL-10 in the mucosal immune system. We conclude that monoassociation with L. delbrueckii UFV-H2b20 protects mice from death caused by L. monocytogenes infection by favoring effector responses while preventing their immunopathological consequences.
authors.affiliation: Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas/ICB, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, Belo Horizonte, MG 31270-901, Brazil.
authors.forename: Liliane Martins
authors.initials: LM
authors.lastname: dos Santos
authors.forename: Mônica Morais
authors.initials: MM
authors.lastname: Santos
authors.forename: Humberto Pereira
authors.initials: HP
authors.lastname: de Souza Silva
authors.forename: Rosa Maria Esteves
authors.initials: RM
authors.lastname: Arantes
authors.forename: Jacques Robert
authors.initials: JR
authors.lastname: Nicoli
authors.forename: Leda Quercia
authors.initials: LQ
authors.lastname: Vieira
mesh_terms: D000818:Animals; D000898:Antibiosis; D005856:Germ-Free Life; D018928:Immunity, Mucosal; D007371:Interferon-gamma / Q000378:metabolism; D016753:Interleukin-10; D048668:Lactobacillus delbrueckii / Q000276:immunology* / Q000502:physiology; D008089:Listeria monocytogenes / Q000254:growth & development*; D008088:Listeriosis / Q000276:immunology* / Q000401:mortality / Q000517:prevention & control*; D008099:Liver / Q000382:microbiology; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D010529:Peritoneal Cavity / Q000382:microbiology; D019936:Probiotics; D013154:Spleen / Q000382:microbiology; D016019:Survival Analysis; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D009569:Nitric Oxide; D007371:Interferon-gamma