Inhibition of cow’s milk allergy development in mice by oral delivery of β‐lactoglobulin‐derived peptides loaded PLGA nanoparticles is associated with systemic whey‐specific immune silencing

BACKGROUND: Two to four percentage of infants are affected by cow's milk allergy (CMA), which persists in 20% of cases. Intervention approaches using early oral exposure to cow's milk protein or hydrolysed cow's milk formula are being studied for CMA prevention. Yet, concerns regarding safety and/or efficacy remain to be tackled in particular for high‐risk non‐exclusively breastfed infants. Therefore, safe and effective strategies to improve early life oral tolerance induction may be considered. OBJECTIVE: We aim to investigate the efficacy of CMA prevention using oral pre‐exposure of two selected 18‐AA β‐lactoglobulin‐derived peptides loaded poly (lactic‐co‐glycolic acid) (PLGA) nanoparticles (NPs) in a whey‐protein induced CMA murine model. METHODS: The peptides were loaded in PLGA NPs via a double emulsion solvent evaporation technique. In vivo, 3‐week‐old female C3H/HeOuJ mice received 6 daily gavages with PBS, whey, Peptide‐mix, a high‐ or low‐dose Peptide‐NPs or empty‐NP plus Peptide‐mix, prior to 5 weekly oral sensitizations with cholera toxin plus whey or PBS (sham). One week after the last sensitization, the challenge induced acute allergic skin response, anaphylactic shock score, allergen‐specific serum immunoglobulins and ex vivo whey‐stimulated cytokine release by splenocytes was measured. RESULTS: Mice pre‐treated with high‐dose Peptide‐NPs but not low‐dose or empty‐NP plus Peptide‐mix, were protected from anaphylaxis and showed a significantly lower acute allergic skin response upon intradermal whey challenge compared to whey‐sensitized mice. Compared with the Peptide‐mix or empty‐NP plus Peptide‐mix pre‐treatment, the high‐dose Peptide‐NPs‐pre‐treatment inhibited ex vivo whey‐stimulated pro‐inflammatory cytokine TNF‐α release by splenocytes. CONCLUSION & CLINICAL RELEVANCE: Oral pre‐exposure of mice to two β‐lactoglobulin‐derived peptides loaded PLGA NPs induced a dose‐related partial prevention of CMA symptoms upon challenge to whole whey protein and silenced whey‐specific systemic immune response. These findings encourage further development of the concept of peptide‐loaded PLGA NPs for CMA prevention towards clinical application.