Bioinformatics and Proteomics Evaluations to Consider IgE Binding Assays for Potential Cross-Reactivity Between House-Cricket (Aceta domesticus) Used in Food, Crustaceans and Cockroaches

RATIONALE: Humans have consumed insects throughout history. However regulators in the United States are asking for assurance that new food products containing processed, cultured insects are safe for crustacean allergic subjects, based on comparisons of genomic, transcriptomic or proteomic data. House-crickets (Acheta domesticus) are being used for food production and were the focus of this study of potential cross-reactivity.

METHODS: The transcriptome of the cricket was reported by the Malik lab (DOI: 10.755/elife.03676). We assembled their data using Velvet and Spades programs. Probable contiguous transcripts were identified using Blastx. Results were compared to the AllergenOnline.org database to find potentially significant alignments, focusing on allergens from the WHO/IUIS Allergen.org database: tropomyosins, arginine kinases, myosin light chain, troponin C, hemocyanin and triosephosphate isomerase. Predicted protein sequences were used to evaluate proteomic data of Aceta domesticus obtained by LC-MSMS to determine confirm the presence from a likely food preparation. Limited serum IgE studies were performed to identify shared IgE binding

RESULTS: Nucleotide sequences predicted protein sequences. The identities of cricket proteins were higher to cockroach than crustaceans proteins. The LC-MSMS confirmed the presence of a number of proteins. Serum IgE tests using a limited number of donors suggest differences in binding. Yet these data are preliminary and demonstrate the complexity answering regulatory questions. The abundance of the proteins and stability in food contribute to risks. Multiple IgE binding methods are needed to confirm cross-reactivity.

CONCLUSIONS: This study shows that it is not yet possible to clearly determine risks for crustacean allergic subjects based only on sequence information.