Allergenicity

Peanut protein epitopes masked by matrix-bound polyphenols

Background and Research Relevance
Food allergies not only have a detrimental impact on quality of life, they also can present life-threatening consequences. The overall incidence of food allergies is increasing, and creating serious public health concerns. Approximately 5% of young children and 3-4% of adults suffer from food allergy particularly in westernized countries (Sicherer & Sampson, 2010). Interestingly, >170 foods have been identified as potential causes for allergic immune responses, however, only a minority of those are responsible for the majority of reactions (Boyce et al., 2010). In fact, the ‘big eight’ foods, namely milk, egg, peanut, tree nuts, shellfish, fish, wheat and soy are commonly recognized as the main triggers for food allergic reactions, depending on the geographic region (Hefle, Nordlee & Taylor, 1996).
The allergic reaction occurs in response to certain proteins (allergens) within a food. These, usually harmless, are recognized by the immune system of sensitive individuals as harmful foreign material. A person who is susceptible to food allergy will, after exposure to a food allergen, produce/activate certain immune cells and antibodies which eventually recognize the allergen after re-exposure to the same allergen. As a matter of fact, physical symptoms (allergic reaction) occur, when, upon (re)consumption, segments of the allergenic protein, called epitopes, bind and cross-link to allergen-specific immunoglobulin E (IgE) antibodies on mast cell and basophil surfaces (certain immune cells), triggering those to release a variety of immunomodulatory compounds (such as histamine) into the body system responsible for local and systemic reactions. Delayed-type reactions, involving a range of immune cells, in some food allergies, can also lead to allergic physical symptoms (i.e. hives, rashes, gastrointestinal discomforts or even anaphylactic shock).

Novel Strategy to Attenuate Protein Allergenicity
With the contribution of research collaborators and experts in food allergy/immunotherapy and peanut chemistry, our lab was very recently able to demonstrate that the stable binding of phytoactive compounds from food grade fruit and herbal extracts to edible proteins (in the form of milled roasted peanut flour) lead to the formation of phytoactive-protein matrices with reduced allergenicity. While our research is still expanding, preliminary results with peanut allergens suggest that our work could potentially be a big step forward in helping affected individuals with peanut and possibly other food allergies.     Funding:  USDA ARS

For Further Information
Plundrich, N.; Kulis, M.; White, B. L.; Grace, M. H.; Guo, R.; Burks, A. W.; Davis, J. P. and Lila, M.A. (2014).  Novel strategy to create hypoallergenic peanut protein-polyphenol edible matrices for oral immunotherapy. Journal of Agricultural & Food Chemistry 62:7010-7021. http://dx.doi.org/10.1021/jf405773b

Plundrich, Nathalie, Brittany White, Lisa L. Dean, Jack P. Davis, E. Allen Foegeding, and Mary Ann Lila. (2015) Stability and immunogenicity of hypoallergenic peanut protein-polyphenol complexes during in vitro digestion. Food & Function 6:2145-2154. DOI: 10.1039/C5FO00162E

References
Boyce, J. A., Assa’ad, A., Burks, A. W., Jones, S. M., Sampson, H. A., Wood, R. A., Plaut, M., Cooper, S. F., Fenton, M. J., Arshad, S. H., Bahna, S. L., Beck, L. A., Byrd-Bredbenner, C., Camargo, C. A. J., Eichenfield, L., Furuta, G. T., Hanifin, J. M., Jones, C., Kraft, M., Levy, B. D., Lieberman, P., Luccioli, S., McCall, K. M., Schneider, L. C., Simon, R. A., Simons, F. E., Teach, S. J., Yawn, B. P., & Schwaninger, J. M. (2010). Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel, J Allergy Clin Immunol 126: S1-S58.

Hefle, S. L., Nordlee, J. A., & Taylor, S. L. (1996). Allergenic foods. Crit Rev Food Sci 36: S69-S89.

Sicherer, S. H., & Sampson, H. A. (2010). Food allergy. J Allergy Clin Immunol 125: S116-S125.