Termite Proteins Cross-React with Cockroach Allergens

Authors: Mattison, Chris; KHURANA, TARUNA - Us Food & Drug Administration (FDA); TARVER, MATTHEW - Bayer Cropscience; Florane, Christopher; Grimm, Casey; PAKALA, SUMAN - University Of Georgia; COTTONE, CARRIE - New Orleans Mosquito, Termite & Rodent Control Board; RIEGEL, CLAUDIA - New Orleans Mosquito, Termite & Rodent Control Board; SLATER, JAY - Food And Drug Administration(FDA)

Submitted to: Allergy and Immunology Meeting American Academy
Publication Type: Abstract Only
Publication Acceptance Date: 11/24/2015
Publication Date: 3/7/2016
Citation: Mattison, C.P., Khurana, T., Tarver, M., Florane, C.B., Grimm, C.C., Pakala, S., Cottone, C., Riegel, C., Slater, J.E. 2016. Termite Proteins Cross-React with Cockroach Allergens. Allergy and Immunology Meeting American Academy. 137:2.

Interpretive Summary: Shrimp are among a group of 8 foods that commonly cause food allergy. Shrimp allergens can be recognized by human IgE to cockroach allergens. This cross-reaction, or recognition of similar proteins by IgE, can complicate diagnostic and therapeutic allergy strategies. Termites are evolutionarily very similar to cockroaches. Edible insects, such as cockroaches and termites are beginning to be popularized as an alternate source of protein and have a high nutrition value. Identification cross-reactivity between commonly consumed food proteins and edible insects is important for food safety and to enable improvements in allergy diagnosis and therapy. The Formosan subterranean termite Coptotermes formosanus (C.f.) is one of the most common species in the southern United States. We characterized similarities between cockroach allergens and termite proteins by analyzing gene and protein sequences. Gene and protein sequencing results indicate there are important similarities between predicted termite proteins and German and American cockroach allergens. Antibody and human serum IgE testing indicates there are significant cross-reactions between termite proteins and cockroach allergens. This research likely has important consequences in the allergy field, especially for those areas where human dwellings are infested by termites. Continued work is needed to better characterize termite proteins as potential allergens.

Technical Abstract: Shrimp are among a group of 8 foods that commonly cause food allergy, and shrimp allergens have been demonstrated to cross-react with arthropod proteins, such as those from cockroaches. Edible insects are beginning to be popularized as an alternate source of protein and have a high nutrition value. Identification cross-reactivity between commonly consumed food proteins and edible insects is important for food safety and to enable improvements in allergy diagnosis and therapy. Allergy to cockroach is a significant problem in urban areas infested with the insects. Cockroach allergens can be inhaled and lead to serious asthma symptoms and hospitalization. Termites are evolutionarily related to cockroaches, co-habitate in human dwellings, and are an increasing pest problem in the United States. The Formosan subterranean termite Coptotermes formosanus (C.f.) is one of the most common species in the southern United States. Due to the evolutionary relationship between the two insects, we sought to determine if C.f. termite proteins could cross-react with cockroach allergens. Sequencing results indicate greater than 60% homology between predicted termite proteins and German and American cockroach allergens including Bla g 3/Per a 3, Bla g 6/Per a 6, Bla g 7/Per a 7, Bla g 8, and Per a 9. We observed peptides matching those of the tropomyosin (Bla g 7), arginine kinase (Per a 9), and myosin (Bla g 8) cockroach allergens using mass-spectrometry. Immunoblot and ELISA testing with rabbit antibodies to cockroach allergens revealed cross-reaction to proteins from termite extracts. In particular, anti-cockroach allergen antibodies were reactive to putative termite homologs of hemocyanin (Bla g 3) and tropomyosin (Bla g 7). Further, IgE in sera samples from cockroach allergic individuals cross-reacted with proteins in termite extracts. Our findings support the conclusion that termite proteins including the hemocyanin and tropomyosin orthologs are cross-reactive with cockroach allergens. This research may have important consequences in the allergy field, especially for those areas where human dwellings are infested by termites. Continued work is needed to better characterize allergen cross-reacting termite proteins.