Cows that eat grass get more vitamin A which may protect consumers against milk allergens

Cows fed with organic food that contain the active vitamin A metabolite retinoic acid (RA) inhibits its ability to cause an allergic reaction in the large-scale production of its milk. The findings of the study, published in the journal Scientific Reports, looked at whether the milk allergen beta-lactoglobulin (Bos d 5) can be loaded with RA and cause a difference in immune responses.

• To test this theory, bovine Bos d 5 was procured, together with RA.
• Using in silico docking, the geometry of Bos d 5 was studied. This was done by taking the crystal structure of its complex using RA.
• Researchers found that Bos d 5 is able to bind RA, with differing results in the immune system for both the loaded (holo-) and empty (apo-) forms.
• When Bos d 5 is loaded with RA, it can inhibit an immune response. Moreover, the Th2 lymphocytes in the body which are made to fight the proteins in milk are unresponsive.
• On the other hand, apo-Bos d 5 displayed an evident immunogenic effect.

Researchers conclude that loading milk with retinoic acid can reconstruct milk from being an allergen to a tolerogen.

Find the full text of the study at this link.

Journal Reference:

Hufnagl K, Ghosh D, Wagner S, Fiocchi A, Dahdah L, Bianchini R, Braun N, Steinborn R, Hofer M, Blaschitz M, et al. RETINOIC ACID PREVENTS IMMUNOGENICITY OF MILK LIPOCALIN BOS D 5 THROUGH BINDING TO ITS IMMUNODOMINANT T-CELL EPITOPE. Scientific Reports. 2018;8(1). DOI: 10.1038/s41598-018-19883-0