Lactococcus lactis as a delivery system for surface displayed mimotopes of major peanut allergen Ara h 2

The prevalence of peanut allergy has been steadily increasing over the last decades. Among food allergies it shows the highest severity and is potentially fatal. Allergen Ara h 2 stands out as the main elicitor of allergic reactions. Research in the field of peanut immunotherapy still strives to improve the significant drawbacks of currently approved therapeutics. In this study we tested three epitope-like peptides as epitope-specific treatment. The epitope-like peptides (mimotopes) of major peanut allergen Ara h 2 were expressed as fusions with scaffold protein - lactococcal peptidoglycan binding domain of AcmA. Mimotope-decorated L. lactis and mimotope-AcmA fusion proteins were characterized. The mimotopes retained the ability to bind IgE from peanut-allergic patients' sera. They showed low basophil activation in peanut-allergic patients, except for mimotope DHPRYGP fused to AcmA suggesting its allergenic activity was partially preserved due to the highest similarity with Ara h 2 epitope. Mimotopes fused to AcmA can elicit T cell response; the increased secretion of IFN-γ suggests the shift of T cell immune response to non-allergic type 1. The use of recombinant L.lactis as a delivery system for surface displayed mimotopes represents a promising strategy that would enable delivery and expression of mimotopes on mucosal surfaces and at the same time beneficial immunomodulating properties.