Identifizierung potentiell allergener Soja-Epitope mittels Peptid Phage Display

Abstract

This thesis dealt with detailed identification of soy related epitopes. The precise mapping of antibody epitopes allows a more detailed and differentiated understanding of immune-related diseases. It may lead to the development of novel therapies and diagnostic tools. Here, we describe the identification of new or more confined epitopes in food allergy-associated soy proteins. By the combination of an optimized peptide-phage display library with next-generation sequencing, sophisticated in silico data analysis and subsequent peptide microarray analysis it was possible to identify 405 potential epitope motifs in 14 soybean proteins. More than 60% of them have not yet been described as potential allergens. Epitopes are described in soy proteins, which have not been known as potentially allergenic before. This approach to applying the peptide phage display is a successful method for the identification of large numbers of valid epitopes, as is shown here. Eighty-three peptides, representing the 42 most frequently found epitope candidates, were validated by microarray analysis using 49 sera from patients who had been tested positive in skin prick test (SPT). Of these, 56 were bound by antibodies either by serum IgE or by serum IgG antibodies or by both. Individual epitope patterns were found for each patient and protein. The combination of a few peptides meets the criteria for the characterization of patient sera. Microarray analysis is the method of choice for the detection of individual patients epitope patterns as well as for the sensitization pattern. The epitope resolved analyses reveal a high prevalence of IgE binding to certain epitopes from patients with clinical symptoms. Evaluation of individual immune profiles of patients with soy sensitization allows the identification of peptides with the potential to broadly study individual IgE/IgG binding to epitopes for the first time.