Nanoallergens: A Nanoparticle Based Platform for Assessment of Immunogenic Peanut Epitopes in a Clinical Population

RATIONALE: Currently, the only way to reliably diagnose the severity of a patient’s allergic condition is through a food challenge, which is inherently dangerous to the patient. In our laboratory, we have developed a novel technique called nanoallergens which can predict the severity of a patient’s allergy.

METHODS: Nanoallergens were designed to effectively display individual allergen epitopes from the major peanut proteins Ara h2 and Ara h 6 on their surfaces. As we demonstrate in our experiments, the detailed engineering of these nanoallergens make them very efficient in triggering degranulation in an in vitro degranulation assay with RBL cells primed with peanut allergy patient serum (purchased from a commercial source (N=4)). We also proved their efficiency in degranulation assays using blood samples obtained from children between the ages of 2-15 with clinical history of peanut allergies (N=6). Lastly, nanoallergens were used in a basophil activation test (BAT) triggered by individual Ara h 2 and Ara h 6 epitopes to determine the extent of immunogenicity of these peanut protein epitopes. Identified immunogenic epitopes were then compared to clinical histories.

RESULTS: In vitro analysis from initial RBL cell studies revealed a group of 10 IgE binding epitopes that were then used in the ex vivo BAT analysis. BAT testing demonstrated a group of epitopes common to patients with a history of urticarial reactions but no anaphylaxis reactions.

CONCLUSIONS: This preliminary study demonstrated that nanoallergens can be used with BAT to efficiently determine the immunogenic epitopes for a particular patient and potentially predict clinical reactions to allergens.