Location: Food Processing and Sensory Quality Research
2020 Annual Report
Accomplishments
1. The first food approved by FDA as a pharmaceutical. Oral immunotherapy is a promising approach to desensitize food allergic individuals, which involves daily ingestion of gradually increasing doses of an allergic food over time. Until this year (2020) no treatment has been available for peanut allergy. Standardized pharmaceutical drug development requires extensive characterization and quality control. ARS scientists in New Orleans, Louisiana have facilitated this by developing and transferring multiple chemical, physical and immunological tools and methods necessary for extensive analysis of the allergens in peanut flour. Peanut flour is the very first food to be characterized as a pharmaceutical and approved by FDA. This drug is now marketed as oral immunotherapy for treatment of peanut allergy.
2. Generation of Big Data on the IgE and IgG4 epitopes of peanut and tree nut allergens. IgE is the antibody mediator of allergic symptoms and IgG4 is thought to block IgE binding to allergens. Due to symptom differences, it is unknown if the IgE and IgG4 binding to allergens is different in various locations around the world. ARS scientists in New Orleans, Louisiana, completed the screening of ~700 patient sera from various locations around the U.S. and the world for IgE and IgG4 binding to intact allergen and fragments of those allergens (peptides) using microarray technology. This data allows ARS to establish a Big Data, searchable database to identify the major reactive allergic proteins and parts of those allergens that are most involved in allergic reactions in different location around the U.S. which in turn, will allow development and use of more targeted and individualized therapeutics and diagnostics for allergic consumers.
3. Identification of peptide combinations that enhance diagnosis of peanut allergy over the existing methods. The only reliable diagnosis for a food allergy is oral food challenge which is time consuming, laborious, costly and dangerous. ARS scientists in New Orleans, Louisiana, hypothesized that an in vitro blood test could replace oral food challenge. Preliminary multivariant analysis of the IgE/IgG4 peptide binding patterns of blood serum from proximately 200 peanut allergic and non-allergic individuals from around the U.S. indicates that this method improves diagnosis of peanut allergy over the existing in vitro marketed methods and may be a real alternative to oral food challenge. Also, IgE epitopes of peanut allergic children in UK identified by microarray showed that addition of Ara h 2-IgE epitopes to intact Ara h 2 enhance the existing diagnostic accuracy of intact Ara h 2-specific IgE measurements alone. Improved diagnostics would reduce the cost, length, and number of physician visits and the difficulties and dangers associated with diagnosis of food allergy by oral food challenge.
4. Discovery of peptide biomarkers that may indicate responsiveness to oral immunotherapy. Oral immunotherapy is a promising treatment for food allergy, but currently the outcomes of this treatment is measured by oral food challenge. ARS scientists in New Orleans, Louisiana, have compared the patient serum IgE/IgG4 peptide recognition patterns from pre and post peanut oral immunotherapy Phase 2 and 3 trials with a collaborator. The data will lead to biomarker (or individual peptides) discovery that will allow physicians to monitor the progress of desensitization and as an endpoint test for oral immunotherapy that doesn’t involve oral food challenge (invention disclosure filed).
5. Proteomic analysis of pecan nut development. The timing and levels of allergen accumulation in pecan nut and its association with weather and other plant traits are not known. Therefore, ARS scientist at New Orleans, Louisiana, have compared the timing and accumulation of proteins in developing pecan nuts. Mass-spectrometric analysis of pecan nut samples allowed the identification of 556 different proteins. Computerized comparisons allowed ARS researchers at New Orleans, Louisiana, to characterize the accumulation of individual proteins and compare this process between different pecan cultivars. This process revealed 26 protein spots that accumulated differentially between the cultivars tested. These results can be used to correlate important characteristics like drought tolerance, pest resistance, and allergen accumulation to specific proteins and may improve breeding strategies resulting in pecan nuts with reduced allergen content and increased quality and yield.
6. Identification of novel allergens in peanut and walnut that contribute to cross-reactivity. Cross-reaction of allergic individuals with peanut and tree nut allergens is a commonly seen problem and allergists generally recommend that patients with an allergy to one nut avoid all nuts. This poses a serious quality of life and nutritional problem for the patient and their family, as many nut allergic individuals have multiple allergies (i.e. egg, milk, wheat, soy, etc). ARS scientists in New Orleans, Louisiana, identified fragments of Ara h 1 (a major peanut allergen) and Jug r 2 (a major walnut allergen) from peanut and walnut, that were thought to be degraded within the nut by a combination of bioinformatics prediction, immunoassays and shown to contribute to cross-reactions among walnut and peanut allergic individuals. They were submitted and accepted as novel allergens by the World Health Organization-Allergen Nomenclature Sub-Committee. Parts of these new allergens were found to be repeated among major allergens which could to contribute even further cross-reactivity among nuts. Understanding what causes cross-reactivity, will allow allergists to eliminate relevant nuts and foods from a patient’s diet as opposed to blanket eliminations that are commonly practiced today.
Review Publications
Filho, E.G., Silva, L.A., Filho, F., Rodrigues, S., Fernandes, F.A., Gallo, M., Mattison, C.P., De Brito, E.S. 2019. Cold plasma processing effect on cashew cuts composition and allergenicity. Food Research International. 125:108621. https://doi.org/10.1016/j.foodres.2019.108621.
Maleki, S.J., Crespo, J.F., Cabanillas, B. 2019. Anti-inflammatory effects of flavonoids. Journal of Food Chemistry. 299:125124. https://doi.org/10.1016/j.foodchem.2019.125124.
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.
Ghasemi, A., Falak, R., Mohammadi, M., Maleki, S.J., Assarezadegan, M.A., Jafary, M. 2020. Incorporation of T-cell epitopes from tetanus and diphtheria toxoids into in-silico-designed hypoallergenic vaccine may enhance the protective immune response against allergens. Iranian Journal of Basic Medical Sciences. 23:636-644.
Novak, N., Maleki, S.J., Cuadrado, C., Crespo, J.F., Cabanillas, B. 2020. Interaction of monocyte-dervied dendritic cells with Ara h 2 from raw and roasted peanut. Foods. 9:863. http://dx.doi.org/10.3390/foods9070863.
Santos, A., Nuno, B., Hurlburt, B.K., Sneha, R., Kwok, M., Bahnson, H., Cheng, H., James, L., Maleki, S.J., Lack, G., Gould, H., Sutton, B. 2020. IgE to epitopes of Ara h 2 enhance the diagnostic accuracy of Ara h 2-specific IgE. Allergy. https://doi.org/10.1111/all.14301
Nesbit, J.B., Schein, C.H., Braun, B.A., Gipson, S.A., Cheng, H., Hurlburt, B.K., Maleki, S.J. 2020. Epitopes with similar physicochemical properties contribute to cross reactivity between peanut and tree nuts. Molecular Immunology. https://doi.org/10.1016/j.molimm.2020.03.017.
Xie, M.M., Liu, H., Yang, K., Koh, B., Wu, H., Maleki, S.J., Hurlburt, B.K., Kaplan, M.H., Dent, A.L. 2020. Peanut-specific IgE produced in a mouse food allergy model requires help from T follicular regulatory cells and IL-10 signaling by B cells. Journal of Clinical Investigation. 130(7):3820-3832. https://doi.org/10.1172/JCI132249.
Mcbride, J.K., Cheng, H., Maleki, S.J., Hurlburt, B.K. 2019. Purification and characterization of pathogenesis related class 10 panallergens. Foods. 8:609-623. https://doi.org/10.3390/foods8120609.
