Preliminary studies on the prevention of the ovalbumin-induced allergic response response by Enterococcus faecalis CECT7121 in mice

CASTRO MARISA SILVIA; AZPIROZ MARÍA BELÉN; MOLINA MATÍAS ALEJANDRO; MOURELLE ANA CAROLINA; ALANIZ FLAVIA S; MALDONADO ANA MARÍA; MANGHI MARCELA ALEJANDRA

INTERNATIONAL ARCHIVES OF ALLERGY AND IMMUNOLOGY

KARGER

Lugar: Basel; Año: 2011 p. 1 - 11

1018-2438

Background: Allergic diseases are featured by an increased production of IgE due to an imbalance of the immune response towards a Th2 profile. In this work, the ability of Enterococcus faecalis CECT7121 to regulate this Th2 exaggerated response in a murine model of ovalbumin (Ova)-induced allergy was studied. Methods: BALB/c mice intragastrically inoculated with E. faecalis CECT7121 before and during a subcutaneous immunization protocol with Ova were studied in comparison with an immunized control group. The allergen specific immune response (IgE, IgG, IgG1 and IgG2a) was assessed. The proliferative activity of memory splenocytes and the levels of IL-4, IL-5, IL-13, IL-10, IL-12 and IFNg were also determined. Results: Upon treatment with E. faecalis CECT7121 the following effects were observed: 1) a decrease of specific IgE levels; 2) an increase of anti-Ova IgG2a levels; 3) the levels of anti-Ova IgG and IgG1 remained unaltered; 4) a reduction in the proliferative rate of memory cells; 5) a decrease in the levels of the Th2 cytokines IL-4, IL-5 and IL-13; 6) the secretion of IL-10, IL-12 and IFNg remained unchanged. Moreover, the incubation of human basophils with non-viable E. faecalis CECT7121 together with an allergen preparation induced the release of B-hexosaminidase at levels that were lower than control reactions and similar to the spontaneous release. Conclusions: In this model, the ig administration of E. faecalis CECT7121 hampers the establishment of the Ova-induced allergic immune response, suggesting that this strain could be useful for the treatment of IgE-mediated allergic diseases.