A cashew specific monoclonal antibody recognizing the small subunit of Ana o 3

Authors: Mattison, Chris; VANT-HALL, BARRY - Contiguity Consulting; BREN-MATTISON, YVETTE - Biomed Bridge; Grimm, Casey

Submitted to: Toxicology Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2019
Publication Date: 7/16/2019
Citation: Mattison, C.P., Vant-Hall, B., Bren-Mattison, Y., Grimm, C.C. 2019. A cashew specific monoclonal antibody recognizing the small subunit of Ana o 3. Toxicology Reports. 6:736-744. https://doi.org/10.1016/j.toxrep.2019.06.018.
DOI: https://doi.org/10.1016/j.toxrep.2019.06.018

Interpretive Summary: Food allergies represent a significant medical burden, and preventing accidental exposure to food allergens requires constant attention. Reactions to cashew nuts can often be severe. One of the dominant cashew allergens is called Ana o 3. Ana o 3 is a small protein composed of 2 smaller subunits held together by disulfide bonds. The Ana o 3 protein remains soluble even after extensive heating of cashew nuts. The stability and solubility properties of Ana o 3 make it an excellent target for testing and detection of cashew allergens. A monoclonal antibody, called 2H5, was developed that recognizes several forms of Ana o 3. For example, the 2H5 monoclonal anti-Ana o 3 antibody can distinguish between native and recombinant Ana o 3 proteins. This antibody specifically recognizes cashew nut extracts in immuno-assays. The 2H5 antibody epresents a useful reagent for the study of antibody cashew-allergen interactions and may enable the development of cashew-specific diagnostic tools that can be used to prevent accidental cashew allergen exposures.

Technical Abstract: Food allergies represent a significant medical burden and preventing accidental exposure to food allergens requires constant attention. Reactions to cashew nuts can often be severe, and the small 2S albumin, Ana o 3, is an immuno-dominant cashew allergen. Ana o 3, like other 2S albumins, is composed of five alpha helices, contains 2 subunits held together by disulfide bonds, and the protein remains soluble even after extensive heating of cashew nuts. The stability and solubility properties of Ana o 3 make it an excellent target for diagnostic and detection methods and tools. In this work, a monoclonal antibody, designated 2H5, aimed at amino acids 39-54 within helices I and II of the small subunit of Ana o 3 was developed that recognizes both recombinant and native Ana o 3 and is cashew specific in ELISA experiments. The KD against the targeted amino-acid sequence was found to be approximately 7.0x10-6 mg/ml (3.3 nM), while the KD against the native protein was found to be approximately 1.2x10-3 mg/ml (92 nM). The 2H5 monoclonal anti-Ana o 3 antibody can distinguish between native and recombinant proteins and represents a useful reagent for the study of antibody cashew-allergen interactions and may enable the development of cashew-specific diagnostic tools that can be used to prevent accidental cashew allergen exposures.