Immunomodulation properties of beta-lactoglobulin hydrolysates by Lactobacillus delbrueckii subsp. bulgaricus CRL 656

HEBERT EM; L. SAAVEDRA; FONT DE VALDEZ G; PESCUMA, M; MOZZI, F

San Miguel de Tucumán

Simposio; SIBAL 2016. V International Symposium on Lactic Acid Bacteria. Benefitting from Lactic Acid Bacteria. Progress in Health and Food.; 2016

CERELA_CONICET

Beta-lactoglobulin (BLG) is the major whey protein and the main cause of allergy in infants. Recently, it has been established that some infant formulas containing partially hydrolyzed caseins and whey proteins could reduce the risk of milk allergy in children with family history of atopy. The aim of this work was to analyze the immunomodulatory potential of BLG hydrolysates by Lactobacillus delbrueckii subsp. bulgaricus CRL 656. Balb/c mice (3-4 week-old females) coming from the second generation of mice fed with a milk protein-free diet were administered with BLG, BLG hydrolysate by L. delbrueckii subsp. bulgaricus CRL 656 (H656), a commercial hydrolysate (BioZate), or PBS by intragastric gavage. Then, all mice were sensitized on day 14 by intraperitoneal administration of BLG using aluminum as adjuvant. The efficacy of mice sensitization was assessed by quantitative measurement of BLG-specific IgE antibodies on individual serum. Spleens were pooled within the same group to evaluate cytokine production by extracting cells under re-stimulation with BLG, H656 or BioZate using a BD kit Th1/Th2/Th17. Mice intestines were fixed and stained with hematoxylin and eosin. Results showed that the group previously gavaged with PBS (allergic) showed 37-fold higher IgE values than those receiving BLG, while those gavaged with H656 or BioZate showed 8 and 4 times lower IgE values, respectively. Spleen cells re-stimulation with H656 resulted in a lower secretion of IL-4 in all tested groups. Interestingly, IL-4 secretion in PBS gavaged group was lower for H656 re-stimulated cells (15.1 ng/ml) than for BLG (37.1 ng/ml) or BioZate (31.6 ng/ml). On the contrary, INF? secretion was higher (2-2.9 times) when cells were stimulated with H656; an opposite effect was observed for BioZate, which inhibited INF? secretion (1.6-3.2 times). IL-10 secretion was higher in the allergic group only when H656 was used to re-stimulate the cells (425 ng/ml), while BioZate and BLG re-stimulation showed similar concentrations than the control (254 ng/ml). The small intestine from the allergic group showed severe alterations in the gut mucosa and leukocyte infiltration, being these alterations diminished in tolerant and H656 gavaged mice. These results indicate that BLG hydrolysates by L. delbrueckii subsp. bulgaricus CRL 656 are less immunoreactive than BLG and may in vitro immunomodulate INF?, IL-10 and IL-4 secretion by spleen cells of allergic and control mice.