CERELA   05438
CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Mechanisms of the innate immune response induced by probiotic bacteria in the protection against Salmonella enterica serovar Typhimurium infection
Autor/es:
CASTILLO N, A; PERDIGÓN G.; DE MORENO DE LEBLANC, A
Lugar:
Buenos Aires
Reunión:
Otro; First French-Argentine Immunology Congress LVIII Reunión Anual de la Sociedad Argentina de Inmunología XIII Jornada Científica del Grupo Rioplatense de Citometría de Flujo 3º Jornadas Argentinas de Inmunodeficiencias Primarias (SAP); 2010
Institución organizadora:
Sociedad Argentina de Inmunología, Sociedad Francesa de Inmunología
Resumen:
Some probiotic lactic acid bacteria can be useful for the prevention of enteric infections. Oral administration of the probiotic bacterium L. casei CRL 431 (Lc) decreased the severity of Salmonella enterica serovar Typhimurium (ST) infection in BALB/c mice. The aim of this work was to compare the immune mechanisms exerted by Lc with other lactobacilli L. acidophilus CRL 730 (La) and L. delbrueckii ssp.bulgaricus CRL 423 (Lb) in order to elucidate the role of the innate response in the protection against ST. Mice receiving Lc, La, or Lb during 7 days, were challenged with ST and continued receiving them post ST. Infection control (S) did not receive special feeding. Samples were collected the day of the infection and 7 days post ST. Weight loss, mortality and ST traslocation were evaluated. Levels of total and specific s-IgA, IL10, TNFα, IFNγ and IL6 were measured in small intestine (SI) fluids by ELISA, IgA+ cells in histological cuts of SI by IF. Macrophages from peritoneum, spleen and Peyer´s patches were isolated for phagocytosis assay. For mice given Lc, TLRs, macrophages and dendritic cells (DC) markers and CD4+ or CD8+ TL were also analyzed. Mice fed with Lc and Lb decreased mortality compared with S (0% and 20% vs 30%) being Lc the group with less pathogen counts in liver and large intestine. 7 days post ST, Lc increased IL10 (142±9 vs 35±13) and specific s-IgA (0.22±0.11 vs 0.06±0.05) compared to S in SI fluids, and augmented TLR2 (30±6 vs 14±3) TLR5 (20±2 vs 9±2) and TLR9 (17±3 vs 12±3) in SI tissues. IgA+ cells increased in mice given Lc and La compared to S group. Macrophages and DC increased in mice given Lc, TL increases were not observed. Phagocytic activity was higher in mice fed with Lc and Lb than in control mice. We demonstrated that Lc exerted its protective effect against ST through the stimulation of the innate immunity, maintained a regulated immune response with increases of IL10. The importance of the specific anti-pathogen s-IgA released to the intestinal fluid was also observed.