Complexation of whey protein with caffeic acid or (-)-epigallocatechin-3-gallate as a strategy to induce oral tolerance to whey allergenic proteins

Abstract

Proteins and phenolic compounds can interact and form soluble and insoluble complexes. In this study, the complexation of whey protein isolate (WPI) with caffeic acid (CA) or (-)‑epigallocatechin‑3‑gallate (EGCG) is investigated as a strategy to attenuate oral sensitization in C3H/HeJ mice against WPI. Treatment with WPI-CA reduced the levels of IgE, IgG1, IgG2a and mMCP-1 in serum of mice measured by ELISA. This might be related to CD4⁺LAP⁺Foxp3⁺ T and IL-17A⁺CD4⁺ T (Th17) cell activation, evidenced by flow cytometry of splenocytes. Treatment with WPI-EGCG, in turn, decreased the levels of IgG2a and mMCP-1 in serum of mice, possibly by the modulation of Th1/Th2 response and the increase of CD4⁺ Foxp3⁺ LAP^- T and IL-17A⁺CD4⁺ T (Th17) cell populations. In conclusion, WPI-CA and WPI-EGCG attenuated oral sensitization in C3H/HeJ mice through different mechanisms. We consider that the complexation of whey proteins with CA and EGCG could be a promising strategy to induce oral tolerance.

Keywords: Anti-allergic capacity; Cow's milk allergy; Hypoallergenic products; Oral immunotherapy; Protein-phenolic interactions.