Abstract: . . .  inserted in StarLink corn was obtained from a source with no history of allerge- nicity and the novel protein was not structurally similar to known food or environmental allergens, the novel pro- tein was comparatively more resistant to digestive proteolysis than other novel proteins that had been approved for other genetically modified crops. For this reason, StarLink corn was never ap- proved for human consumption. How- ever, given the very low level of exposure to the novel protein in StarLink corn in corn-based food products, the likeli- hood of allergic sensitization to this par- ticular novel protein is low. Despite that and due to the concerns about the po- tential allergenicity of this transgenic variety, it has been withdrawn from the marketplace, although traces may re- main for one or more growing seasons. This episode emphasizes the importance of assessing the potential allergenicity of transgenic varieties as part of the overall safety evaluation process. Agricultural biotechnology can also be used to decrease the inherent allerge- nicity of foods. The proteins in specific foods that are responsible for allergic re- actions could be removed or altered through agricultural biotechnology. While no commercial examples exist yet of the application of this possibility, it is an active area of research with peanuts. Non-IgE Cell-Mediated Reactions As noted earlier, cell-mediated aller- gic reactions, also known as delayed hy- persensitivity reactions, have an onset time of 624 hours after ingestion of the offending food. The reactions develop slowly, reaching a peak at approximately 48 hours and then slowly subsiding over 7296 hours. Cell-mediated food aller- gies involve the interaction between spe- cific antigens or allergens from the food and sensitized, tissue-bound T cells that release inflammatory mediators when sensitized (Sampson, 1991). The role of cell-mediated reactions in food allergies remains somewhat uncertain. Compel- ling and mounting evidence has accu- mulated, however, indicating that celiac disease occurs through a T cell-mediat- ed mechanism (Ferguson, 1997; Strober, 1986). Celiac Disease. Also known as celiac sprue or gluten-sensitive enteropathy, celiac disease is a malabsorption syn- Fig. 3 Decision-tree for assessment of allergenic potential of foods derived from biotechnology (FAO/ WHO, 2001). Assessment of the Allergenic Potential of Foods Derived From Biotechnology Footnotes Any positive results obtained from sequence homology comparisons to the sequences of known allergens in existing allergen databases or from serum screening protocols indicate that the . . .
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