Invited review: The role of the blood–milk barrier and its manipulation for the efficacy of the mammary immune response and milk production

The intact blood–milk barrier (BMB) prevents an uncontrolled exchange of soluble and cellular components between blood milk in the mammary gland. It enables sustainability optimal composition for nourishment offspring. Endothelial cells, connective tissue, basal membrane, mainly epithelial cells provide semipermeability this barrier, allowing only a selective transfer necessary production. are closely connected to each other by different formations, which tight junctions most critical separating milk-containing compartments from surrounding extracellular fluid vasculature. During mastitis, integrity BMB is reduced. This facilitates immune factors such as antibodies into milk. Simultaneously, constituents without obvious function promoted. Furthermore, reduced causes loss circulation. Different mechanisms responsible impairment including junction opening, but also cell degradation. To promote cure targeted manipulation permeability may be tool optimize An intensified opening supports antibody milk, supposed increase contribution specific system defense. On contrary, fast closure during recovery mastitis can accelerate normalization yield. Various agents have been experimentally shown either open (e.g., pathogens pathogen-associated molecular patterns, several nonsteroidal anti-inflammatory drugs, oxytocin, calcium chelators) or close glucocorticoids, natural drugs) BMB.