Profiling serum antibodies with a pan allergen phage library identifies key wheat allergy epitopes

Wheat is one of the most common food allergens in children, but distinguishing true wheat allergy (IgE-mediated, anaphylaxis-prone) from wheat sensitization (asymptomatic IgE positivity) is clinically difficult with conventional whole-protein assays. The same patient may have measurable wheat-specific IgE without symptoms, or experience anaphylaxis from a single named allergen out of dozens of wheat proteins. Identifying which IgE epitopes drive clinical disease requires resolution that whole-extract assays cannot deliver.

To address that gap, the authors built AllerScan, a programmable phage-display library encoding 19,332 overlapping 56-amino-acid peptide tiles drawn from all 1,847 proteins listed in the Allergome database. The library is displayed on T7 bacteriophage and assayed via phage immunoprecipitation sequencing (PhIP-seq), which captures antibody-bound phage from serum and reads them out by next-generation sequencing — producing a residue-resolved map of the patient’s allergen-specific antibody repertoire from microliters of serum.

Applied to 58 food-allergic patients and 25 healthy controls, AllerScan resolved wheat-specific IgE responses at single-epitope resolution. The analysis cleanly separated wheat-allergic patients from wheat-sensitized individuals and surfaced a dominant IgE epitope on alpha-purothionin (Tri a 37) as a serological hallmark of true wheat allergy. Beyond wheat, the pan-allergen design generalizes — AllerScan can in principle profile epitope-resolved IgE/IgG responses across the entire allergome in a single assay, opening a path toward more accurate allergy diagnostics and personalized immunotherapy planning.