Determination of Crucial Immunogenic Epitopes in Major Peanut Allergy Protein, Ara h2, via Novel Nanoallergen Platform

Abstract

Current methods for detection and diagnosis of allergies do not provide epitope specific immunogenic information and hence lack critical information that could aid in the prediction of clinical responses. To address this issue, we developed a nanoparticle based platform, called nanoallergens that enable multivalent display of potential allergy epitopes for determining the immunogenicity of each IgE binding epitope. By synthesizing nanoallergens that present various epitopes from the major peanut allergen, Ara h2, we directly determined the immunogenicity of each epitope, alone and in combination with other epitopes, using patient sera. This information provided insights on which epitopes are most critical for physiological responses to Ara h2 and revealed the importance of both high and low affinity epitopes for allergic responses. We anticipate the nanoallergen platform to be used to provide information regarding allergic reactions and therefore potentially aid in more accurate diagnosis and design of personalized treatment options.

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

“…Our results show that specific peptide reactivity is highly variable between individual patients. A similar observation was reported by Deak et al 47 They developed "nanoallergens", a nanoparticle-based platform for multivalent testing of potential epitopes of Ara h 2 in a cell-based assay. They concluded that some epitopes are more "im-…”

Variable IgE cross‐reactivity between peanut 2S‐albumins: The case for measuring IgE to both Ara h 2 and Ara h 6

“…Based on their medical history, symptoms of the IgE-mediated peanut allergy involved skin, respiratory tract, gastrointestinal tract, and cardiovascular system. Twelve sera from US peanut-allergic patients with a strong history of peanut-induced immediate hypersensitivity and peanut-specific IgE ≥13 KAU/L (ImmunoCap; Thermo Fischer Scientific) in serum were also included (Table S1, sera [21][22][23][24][25][26][27][28][29][30][31][32]. All adult patients and the parents or guardians of minors signed informed consent.…”

“…This absence of distinction is illustrated inFigure 4with nAra h 2 and rAra h 2 displaying similar IgE-binding capacities although the absence of hydroxyproline in rAra h 2 has been shown to reduce the binding affinity of IgE recognizing the DPYSP OH S motifs in nAra h 2. In contrast, assays such as IgE-binding competitive inhibition or in vitro mast cell degranulation can evidence differences of binding affinity and could thus demonstrate the higher allergenic activity of nAra h 2 compared with rAra h 2 22,32. We therefore investigated cross-reactivity between 2S-albumins with a competitive fluidphase assay (Figure 5A).…”

Designer covalent heterobivalent inhibitors prevent IgE-dependent responses to peanut allergen

“…2 and Ara h 6 using the nanoallergen assay system developed in our laboratory (12). Nanoallergens provide multivalent display for allergen epitopes on liposomal surfaces, which are then used to evaluate their immunogenicity via in vitro mast cell degranulation responses ( Fig.…”

“…S2). These nanoallergens multivalently present epitopes on their surfaces with high-precision and controlled stoichiometry (12,14). Nanoallergens were used to trigger degranulation response in RBL-SX38 cells [model mast cell line which expresses human IgE receptor (FceRI)] (15) primed with a specific patient serum (Fig.…”