IMMUNOMODULATION PROPERTIES OF BETA-LACTOGLOBULIN HYDROLYSATES BY Lactobacillus delbrueckii subsp. bulgaricus CRL 656

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

San Miguel de Tucumán

Simposio; International Symposium on Lactic Acid Bacteria; 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 hydrolyzedcaseins and whey proteins could reduce the risk of milk allergy in children with family historyof atopy. The aim of this work was to analyze the immunomodulatory potential of BLG hydrolysatesby Lactobacillus delbrueckii subsp. bulgaricus CRL 656. Balb/c mice (3-4 week-oldfemales) coming from the second generation of mice fed with a milk protein-free diet wereadministered 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 sensitizedon day 14 by intraperitoneal administration of BLG using aluminum as adjuvant. Theefficacy of mice sensitization was assessed by quantitative measurement of BLG-specific IgEantibodies on individual serum. Spleens were pooled within the same group to evaluate cytokineproduction by extracting cells under re-stimulation with BLG, H656 or BioZate usinga 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 higherIgE values than those receiving BLG, while those gavaged with H656 or BioZate showed 8and 4 times lower IgE values, respectively. Spleen cells re-stimulation with H656 resulted in alower secretion of IL-4 in all tested groups. Interestingly, IL-4 secretion in PBS gavaged groupwas 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, INFγ secretion was higher (2-2.9 times) when cells were stimulatedwith H656; an opposite effect was observed for BioZate, which inhibited INFγ secretion(1.6-3.2 times). IL-10 secretion was higher in the allergic group only when H656 was used tore-stimulate the cells (425 ng/ml), while BioZate and BLG re-stimulation showed similar concentrationsthan the control (254 ng/ml). The small intestine from the allergic group showedsevere alterations in the gut mucosa and leukocyte infiltration, being these alterations diminishedin tolerant and H656 gavaged mice. These results indicate that BLG hydrolysates byL. delbrueckii subsp. bulgaricus CRL 656 are less immunoreactive than BLG and may in vitroimmunomodulate INFγ, IL-10 and IL-4 secretion by spleen cells of allergic and control mice