Structure, Function and Epitope Mapping the Peanut Panallergen Ara h 8

Authors: Hurlburt, Barry

Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/16/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: The incidence of peanut allergy continues to rise in the US and Europe. Whereas exposure to the major allergen proteins Ara h 1, 2, 3, and 6 can cause fatal anaphylaxis, exposure to the minor allergens usually does not. Ara h 8 is a minor allergen. Importantly, it is the minor food allergens that are thought to be responsible for Oral Allergy Syndrome (OAS) in which sensitization to airborne allergens causes an allergic reaction to ingested foods. In this work we determined the 3-dimensional structure of Ara h 8.

Technical Abstract: The incidence of peanut allergy continues to rise in the US and Europe. Whereas exposure to the major allergens Ara h 1, 2, 3, and 6 can cause fatal anaphylaxis, exposure to the minor allergens usually does not. Ara h 8 is a minor allergen. Importantly, it is the minor food allergens that are thought to be responsible for Oral Allergy Syndrome (OAS) in which sensitization to airborne allergens causes a Type 2 allergic reaction to ingested foods. Furthermore, it is believed that similar protein structure, rather than a similar linear sequence is the cause of OAS. Bet v 1 from birch pollen is a common sensitizing agent and OAS results when patients consume certain fruits, vegetables, tree nuts and peanuts. This seminar will describe the 3-dimensional structure of Ara h 8, a Bet v 1 homolog. The overall fold is very similar to that of Bet v 1, Api g 1 (celery), Gly m 4 (soy) and Pru av 1 (cherry). Ara h 8 binds the isoflavones quercetin and apigenin, as well as resveratrol avidly. Using peptide micro-arrays and clinically-confirmed allergic patient sera the dominant IgE and IgG4 epitopes have been defined.