Identification of peptides with tolerogenic potential in a hydrolysed whey-based infant formula

Abstract

Background:Failure to induce oral tolerance may result in food allergy. Hydrolysedcow's milk‐based infant formulas are recommended in subjects with a high risk ofdeveloping allergic disease. Presentation of T cell epitopes is a prerequisite to gen-erate regulatory T cells that could contribute to oral tolerance.Objective:To investigate whether a specific hydrolysed whey‐based infant formulacontains peptides that function as T cell epitopes to support the development oforal tolerance to whey.Methods:First, a novel liquid chromatography‐mass spectrometry (LC‐MS) methodwas developed to characterizeβ‐lactoglobulin‐derived peptides present in a specificinfant formula with a focus on region AA#13‐48 ofβ‐lactoglobulin, which has previ-ously been described to contain T cell epitopes with tolerogenic potential. Second,the formula was subjected to the ProImmune ProPresent®antigen presentationassay and MHC class II binding algorithm to identify relevant HLA‐DRB1‐restrictedpeptides. Third, identified peptides were tested on human cow's milk protein‐speci-fic T cell lines to determine T cell recognition.Results:Thirteen peptides of minimal 9AAs long that overlap with AA#13‐48 ofβ‐lactoglobulin were identified. Six of them were found across all batches analysed. Itwas further confirmed that these peptides were processed and presented by humandendritic cells. The identified HLA‐DRB1‐restricted peptides were correlated toAA#11‐30 and AA#23‐39 ofβ‐lactoglobulin. Importantly, the proliferation assayshowed that the synthetic peptides were recognized by cow's milk protein‐specificT cell lines and induced T cell proliferation.Conclusion and Clinical Relevance:This study demonstrates that the tested hydrol-ysed infant formula contains functional HLA‐DRB1‐restricted T cell epitopes, whichcan potentially support the development of oral tolerance to whey.