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

MICAELA PESCUMA; LUCILA SAAVEDRA; ELVIRA MARÍA HÉBERT; FERNANDA MOZZI; GRACIELA FONT DE VALDEZ

Simposio; V simposio internacional de bacterias lacticas; 2016

Beta-lactoglobulin (BLG) is the major whey protein andthe main cause of allergy in infants. Recently, it has been established thatsome infant formulas containing partially hydrolyzed caseins and whey proteinscould 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 BLGhydrolysates by Lactobacillus delbrueckiisubsp. bulgaricus CRL 656. Balb/cmice (3-4 week-old females) coming from the second generation of mice fed witha milk protein-free diet were administered with BLG, BLG hydrolysate by  L.delbrueckii subsp. bulgaricus CRL656 (H656), a commercial hidrolysate (BioZate), or PBS by intragastric gavage. Then,all mice were sensitized on day 14 by intraperitoneal administration of BLG usingalumn as adjuvant. The efficacy of mice sensitization was assessed byquantitative measurement of BLG-specific IgE antibodies on individual serum. Spleens werepooled within the same group to evaluate cytokine production by extractingcells under re-stimulation with BLG, H656 or BioZate using a BD kit Th1/Th2/Th17. Mice intestines werefixed and stained with hematoxylin and eosin. Results showed that the group previouslygavaged with PBS (allergic) showed 37-fold higher IgE values than thosereceiving BLG, while those gavaged with H656 or BioZate showed 8 and 4 times lowerIgE values. Spleen cells re-stimulation with H656 resulted in a lower secretionof IL-4 in all tested groups. Interestingly, IL-4 secretion in PBS gavagedgroup was lower for H656 re-stimulated cells (15.1 ng/ml) than for BLG (37.1ng/ml) or BioZate (31.6 ng/ml). On the contrary, INFg secretion was higher (2-2.9times) when cells were stimulated with H656; an opposite effect was observedfor BioZate, which inhibited INFg secretion (1.6-3.2 times). IL-10 secretion washigher in the allergic group only when H656 was used to re-stimulate the cells(425ng/ml), while BioZate and BLG re-stimulation showed similar concentrationsthan the control (254 ng/ml). The small intestine from the allergic groupshowed severe alterations in the gut mucosa and leukocyte infiltration, beingthese alterations diminished in tolerant and H656 gavaged mice. These results indicatethat BLG hydrolysates by L. delbrueckiisubsp. bulgaricus CRL 656 are lessimmunoreactive than BLG and may in vitroimmunomodulate INFg, IL-10 and IL-4 secretion by spleen cells ofallergic and control mice.