Skin Prick Test Assay Research Articles

The immunome of soy bean allergy: Comprehensive identification and characterization of epitopes.

The precise mapping of multiple antibody epitopes recognized by patients' sera allows a more detailed and differentiated understanding of immunological diseases. It may lead to the development of novel therapies and diagnostic tools. Mapping soy bean specific epitopes relevant for soy bean allergy patients and persons sensitized to soy bean, and analysis of their IgE/IgG binding spectrum. Identification of epitopes using sera, applying an optimized peptide phage display library followed by next-generation sequencing, specially designed in silico data analysis and subsequent peptide microarray analysis. We were able to identify more than 400 potential epitope motifs in soy bean proteins. More than 60% of them have not yet been described as potential epitopes. Eighty-three peptides, representing the 42 most frequently found epitope candidates, were validated by microarray analysis using 50 sera from people who have been tested positive in skin prick test (SPT). Of these peptides, 56 were bound by antibodies, 55 by serum IgE, 43 by serum IgG and 30 by both. Person-specific epitope patterns were found for each individual and protein. For individuals with clinical symptoms, epitope resolved analyses reveal a high prevalence of IgE binding to a few soy bean specific epitopes. Evaluation of individual immune profiles of patients with soy bean sensitization allows the identification of peptides that do facilitate studying individual IgE/IgG epitope binding patterns. This enables discrimination of sensitization from disease, such assay test has the potential to replace SPT assays.

Allergenic activity of a major grass pollen allergen is elevated in the presence of nasal secretion.

Phl p5 is a major allergen of timothy grass and causes rhinitis and bronchial asthma in nearly all patients allergic to grass pollen. The biochemical processing of this molecule by the nasal mucosa at its first encounter and possible changes of its biologic activity are unknown. Two isoforms of the allergen were expressed in Escherichia coli and subsequently purified. Conversion of these preparations to various forms with molecular size between 10 and 20 kD in the presence of nasal secretion was observed. Surprisingly, in skin prick test assays with allergic patients the mixture of converted peptides caused significantly higher allergic response when compared with the parent protein. Allergenic activity of the recombinant N-terminal Phl p5a and the C-terminal Phl p5b as measured by skin prick test and histamine release assays was significantly higher than that of the respective parent molecules. Using pancreatic rather than nasal secretion, Phl p5b was completely degraded and its allergenicity was almost completely reduced. Proteolytic degradation converts Phl p5 to defined fragments with increased allergenicity. Complete degradation of Phl p5 on the mucosa could be a preventive strategy to destroy its potency for the induction of an allergic response.