Cross-serological reaction of glandless cottonseed proteins to peanut and tree nut allergic IgE

Authors: Mattison, Chris; He, Zhongqi; Zhang, Dunhua; DUPRE, REBECCA - Oak Ridge Institute For Science And Education (ORISE); Lloyd, Steven

Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2023
Publication Date: 2/7/2023
Citation: Mattison, C.P., He, Z., Zhang, D., Dupre, R., Lloyd, S.W. 2023. Cross-serological reaction of glandless cottonseed proteins to peanut and tree nut allergic IgE. Molecules. 28(4):1587. https://doi.org/10.3390/molecules28041587.
DOI: https://doi.org/10.3390/molecules28041587

Interpretive Summary: Food allergy is a potentially life-threatening health concern caused by a specific type of antibody called immunoglobulin E (IgE) antibodies. When IgE binds to a normally harmless food protein it can cause very severe allergic reactions. Even very small amounts of allergy-causing foods can trigger symptoms such as hives, swollen airways, or anaphylaxis. Estimates suggest that food allergies affect 8% of children and up to 4% of adults in the United States. The incidence of food allergy appears to be increasing worldwide. A new type of “glandless” cottonseed lacking a toxic compound has created excitement that it may be used for food and feed applications. However, proteins in glandless cottonseed can be similar in amino acid sequence and structure to allergens from peanuts and tree nuts. Peanuts and tree nuts are among a group of eight foods that commonly cause food allergy. To evaluate the potential allergen risk, glandless cottonseed protein extract was evaluated for binding by IgE from peanut and tree nut allergic volunteers. Binding assays demonstrated that eight of thirty-two samples (25%) bound the glandless cottonseed extract. Two proteins in the glandless cottonseed extract were demonstrated to bind IgE. This suggests that future allergen risk assessments and clinical trials evaluating consumption of foods containing glandless cottonseed protein are needed.

Technical Abstract: Food allergy is a potentially life-threatening health concern caused by immunoglobulin E (IgE) antibodies that mistakenly recognize normally harmless food proteins as threats. Peanuts and tree nuts contain several seed storage proteins that commonly act as allergens. Glandless cottonseed, lacking the toxic compound gossypol, is a new food source. However, the seed storage proteins in cottonseed may act as allergens. To assess this risk, glandless cottonseed protein extracts were evaluated for IgE binding by peanut and tree nut allergic volunteers. ELISA demonstrated that 25% of 32 samples had significant binding to cottonseed extracts. Immunoblot analysis with pooled sera indicated that IgE recognized a pair of bands migrating at approximately 50 kDa. Excision of these bands and subsequent mass-spectrometric analysis, demonstrated peptide matches to cotton C72 and GC72 vicilin and legumin A and B proteins. Further, in silico analysis indicated similarity of the cotton vicilin and legumin proteins to peanut vicilin (Ara h 1) and cashew nut legumin (Ana o 2) IgE-binding epitopes among others. The observations suggest both the cotton vicilin and legumin proteins were recognized by the nut allergic IgE, and they should be considered for future allergen risk assessments evaluating glandless cottonseed protein products.