Enterococcus faecalis CECT7121 induces systemic immunomodulatory effectsand protects from Salmonella infection

CASTRO, M; SPARO, M; MOLINA, M; ANDINO, J; MANGHI, M

International Journal of Probiotics and Prebiotics

New Century Health Publishers, LLC

Año: 2007 vol. 2 p. 215 - 224

1555-1431

In this work, the innocuousness of the bacterial strain of Enterococcus faecalis CECT7121 is demonstrated upon intraperitoneal administration to BALB/c mice. When administrated intragastrically during 3 days, this strain implants and persists in the intestinal epithelium for 18 days without affecting the preexisting flora of enterobacteriae. Besides, E. faecalis CECT7121 protected a 50% of the mice challenged intragastrically with Salmonella serotype Enteritidis. The effect of the administration of E. faecalis CECT7121 on the innate immune response was also evaluated. The in vitro stimulus of heat-killed E. faecalis CECT7121 induced the production of IL-12, TNFa and IL-6 (inflammatory cytokines) by peritoneal macrophages in a concentration-dependent manner. The production of IL-10 was also stimulated but only when the highest concentration was employed. However, E. faecalis CECT7121 did not stimulate the proliferative level of splenocytes in culture thus showing an anti-inflammatory effect. The intragastric administration of E. faecalis CECT7121 modified the cytokine pattern expressed by peritoneal macrophages, inducing the synthesis of similar levels of TNFa and IL-12, lower levels of IL-6, whereas IL-10 was not detected. When these cells were stimulated with Salmonella serotype Enteritidis, higher levels of TNFa, IL-6, IL-10 e IL-12 were detected. These results indicate that E. faecalis CECT7121 modulates the innate systemic immune response by inducing the synthesis of homeostatic cytokines (IL-12 and IL-10).