Use of urea-polyacrylamide electrophoresis for discrimination of A1 and A2 beta casein variants in raw cow’s milk

The mechanisms underlying the allergy-protective effects of raw cow’s milk are poorly understood. The current focus is mainly on the modulation of T cell responses. In the present study, we investigated whether raw cow’s milk can also directly inhibit mast cells, the key effector cells in IgE-mediated allergic responses. Primary murine bone marrow-derived mast cells (BMMC) and peritoneal mast cells (PMC), were incubated with raw milk, heated raw milk, or shop milk, prior to IgE-mediated activation. The effects on mast cell activation and underlying signaling events were assessed. Raw milk was furthermore fractionated based on molecular size and obtained fractions were tested for their capacity to reduce IgE-mediated mast cell activation. Coincubation of BMMC and PMC with raw milk prior to activation reduced β-hexosaminidase release and IL-6 and IL-13 production, while heated raw milk or shop milk had no effect. The reduced mast cell activation coincided with a reduced intracellular calcium influx. In addition, SYK and ERK phosphorylation levels, both downstream signaling events of the FcεRI, were lower in raw milk-treated BMMC compared to control BMMC, although differences did not reach full significance. Raw milk-treated BMMC furthermore retained membrane-bound IgE expression after allergen stimulation. Raw milk fractionation showed that the heat-sensitive raw milk components responsible for the reduced mast cell activation are likely to have a molecular weight of > 37 kDa. The present study demonstrates that raw cow’s milk can also directly affect mast cell activation. These results extend the current knowledge on mechanisms via which raw cow’s milk prevents allergic diseases, which is crucial for the development of new, microbiologically safe, nutritional strategies to reduce allergic diseases.

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Biodiversity andγ-Aminobutyric Acid Production by Lactic Acid Bacteria Isolated from Traditional Alpine Raw Cow’s Milk Cheeses

BioMed Research International ◽

10.1155/2015/625740 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 36

Author(s):

Elena Franciosi ◽

Ilaria Carafa ◽

Tiziana Nardin ◽

Silvia Schiavon ◽

Elisa Poznanski ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Random Amplified Polymorphic Dna ◽

Streptococcus Thermophilus ◽

Lactobacillus Paracasei ◽

Aminobutyric Acid ◽

Cow’S Milk ◽

Rrna Gene ◽

Cow's Milk ◽

Raw Cow’S Milk

“Nostrano-cheeses” are traditional alpine cheeses made from raw cow’s milk in Trentino-Alto Adige, Italy. This study identified lactic acid bacteria (LAB) developing during maturation of “Nostrano-cheeses” and evaluated their potential to produceγ-aminobutyric acid (GABA), an immunologically active compound and neurotransmitter. Cheese samples were collected on six cheese-making days, in three dairy factories located in different areas of Trentino and at different stages of cheese ripening (24 h, 15 days, and 1, 2, 3, 6, and 8 months). A total of 1,059 LAB isolates were screened using Random Amplified Polymorphic DNA-PCR (RAPD-PCR) and differentiated into 583 clusters. LAB strains from dominant clusters (n=97) were genetically identified to species level by partial 16S rRNA gene sequencing. LAB species most frequently isolated wereLactobacillus paracasei,Streptococcus thermophilus, andLeuconostoc mesenteroides. The 97 dominant clusters were also characterized for their ability in producing GABA by high-performance liquid chromatography (HPLC). About 71% of the dominant bacteria clusters evolving during cheeses ripening were able to produce GABA. Most GABA producers wereLactobacillus paracaseibut other GABA producing species includedLactococcus lactis,Lactobacillus plantarum,Lactobacillus rhamnosus,Pediococcus pentosaceus, andStreptococcus thermophilus. NoEnterococcus faecalisorSc. macedonicusisolates produced GABA. The isolate producing the highest amount of GABA (80.0±2.7 mg/kg) was aSc. thermophilus.

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