The protective farm effect against allergies in a holoBLG based FSMP (food for specific medical purposes)-lozenge confers immune resilience in BALB/c mice

Abstract

Background: We previously proposed the whey protein beta-lactoglobulin (BLG) loaded with iron-siderophore complexes as the active principle in the farm protective effect against allergies. A lozenge as food for specific medical purposes (FSMP) was formulated to assess its therapeutical efficacy in BALB/c mice and in-vitro experiments. Methods: Binding of iron-catechin into BLG was confirmed by spectroscopy and docking calculations. Serum IgE binding of children allergic to milk, or tolerating milk, was assessed to loaded (holo-) versus empty (apo-) BLG and for human mast cell degranulation. BLG and Bet v 1 double-sensitized mice were orally treated with the lozenge or placebo, and immunologically analysed after systemic allergen challenge. Human PBMCs of pollen allergic subjects were flow cytometrically assessed after stimulation with holoBLG in conjugation with catechin-iron complexes as ligands in a dietary supplement or with the apoBLG. Results: One major IgE- and T cell epitope were masked by catechin-iron complexes, which impaired IgE binding of milk allergic children and degranulation of mast cells. In mice, only supplementation with the lozenge reduced clinical reactivity to BLG and Bet v 1, promoted Tregs, and suppressed antigen presentation. In allergic subjects, stimulation of PBMCs with holoBLG led to a significant increase of intracellular iron in circulating CD14+ cells with significantly lower expression of HLADR and CD86 compared to their stimulation with apoBLG. Conclusion: The FSMP lozenge targeted antigen presenting cells and dampened immune activation in human immune cells and allergic mice in an antigen nonspecific manner, thereby conferring immune resilience against allergic symptoms.