INVESTIGADORES
VINDEROLA Celso Gabriel
congresos y reuniones científicas
Título:
Profile of cytokines induced by non pathogenic lactobacilli interacting with normal intestinal epithelial cells. Implication of TLRs.
Autor/es:
VINDEROLA, C.G.; MATAR, C.; PERDIGÓN, G.
Lugar:
Boston (MA, USA)
Reunión:
Congreso; 12th Internacional Congress of Mucosal Immunology.; 2005
Resumen:
Background: Much of the knowledge about the interactions between intestinal epithelial cells (IECs) and non pathogenic bacteria was obtained using commercial tumoral cell lines. Their responses may give valuable information; however, they may not always reflect the in vivo situation as clearly as newly isolated cells. Methods: small and large IECs from BALB/c mice were isolated and put in contact with different concentrations (108, 107, 106 or 105 CFU/ml) of viable or heat-inactivated cultures of L. casei, L helveticus (with demonstrated effects on the gut immune system) or non pathogenic E. coli. Anti-mouse Toll like receptors 2 and 4 antibodies were also used to block IECs prior to their contact with bacteria. Ex vivo cytokine production was also assessed in IECs from animals fed with lactobacilli for 2, 5 or 7 days. After 8h of co-culture, IL-1á, IL-6 and IL-10 were determined in the supernatants by ELISA. Results: A dose dependant effect was observed in the IL-6 production by IECs for all strain assessed (in vitro and ex vivo). Non viable lactobacilli induced a higher IL-6 production than viable cells (may be due to pro-inflammatory heat-shock proteins). A significant lower amount of IL-6 was induced by lactobacilli than by E. coli. No IL-10 or IL-1á was detected, except IL-1á for E. coli. L. casei was seen to interact with IECs exclusively by TLR2 in the small intestine. For L. casei in the large intestine and for the other strains in the small and large intestine, receptors other than TLRs seem to be involved in the IEC-bacteria interactions. Conclusions: non pathogenic lactobacilli would act as immunomodulators inducing IL-6 in an amount necessary for terminal differentiation of B-cells to plasma cells, to maintain the population of IgA+ cells in the gut. Non pathogenic E. coli induce higher amounts of IL-6 and additionally IL-1á, perhaps the stimuli on the epithelial cells by LPS of Gram(-) bacteria are necessary to initiate the innate immune response.