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

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

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/26/2022
Publication Date: N/A
Citation: N/A

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. Very small amounts of allergy-causing foods can trigger symptoms including hives, swollen airways, or anaphylaxis. Food allergies affect 8% of children and 4% of adults in the United States, and food allergy incidence appears to be increasing worldwide. Peanuts and tree nuts are among a group of eight foods that commonly cause food allergy, and several peanut and tree nut seed storage proteins act as allergens. There is enthusiasm that glandless cottonseed, lacking the toxic phenolic compound gossypol, could be used for feed and food applications because it is a good source of fiber, oil, and protein. However, seed storage proteins in cottonseed can be similar in amino acid sequence and structure to allergens from peanuts and tree nuts. To assess the potential allergen risk for human food applications, glandless cottonseed protein extract was evaluated for binding by IgE from peanut and tree nut allergic volunteers. ELISA demonstrated that eight of thirty-two samples (25%) had relatively low, but significant binding to cottonseed extract. Immunoblot analysis with a pool of these sera indicated a pair of bands migrating at approximately 50 kDa were recognized by the nut allergic sera. Excision of the corresponding 50 kDA bands from SDS-PAGE, trypsin digestion, and mass-spectrometric analysis of extracted peptides demonstrated matches to two vicilins (VCLA_GOSHI and VCLB_GOSHI) and two legumins (LEGA_GOSHI and LEGB_GOSHI). Treatment of the extract with a reducing agent demonstrated redox-sensitive and -insensitive proteins were recognized by the sera. This suggests both the vicilin and legumin proteins were recognized by the nut allergic IgE. The information derived from this work will be helpful for future allergen risk assessments and clinical trials evaluating consumption of glandless cottonseed food products.