Digestibility of allergens extracted from natural rubber latex and vegetable foods

Background: Several cross-reactive allergens are now known to be involved i n the defense responses of higher plants. Such proteins are drawing the att ention of plant breeders because of their antimicrobial or stress-alleviati ng activities. Plants genetically modified to express defense-related prote ins are being developed. The current concern is focused on the allergenicit y of these intentionally expressed proteins. Objective: It is believed that food allergens are proteins resistant to dig estion, Digestibility tests have been accepted as an appropriate method for evaluating the allergenicity of newly introduced proteins. In this study w e investigated the usefulness of this method for dedtecting allergens from natural rubber latex and vegetable foods, Methods: Proteins were extracted from rubber latex, potato, and 5 kinds of fruits, Simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) were used for the digestibility test, An aliquot of each digest was periodi cally withdrawn and analyzed. Allergens were detected with pooled sera from individuals with latex allergy or patients given a diagnosis of oral aller gy syndrome, Results: Most latex and vegetable food proteins were digested by the SGF wi thin 4 minutes. Numerous allergens were also decomposed by the SGF within 8 minutes, Although vegetable food allergens were relatively stable in the S IF, kiwi allergens were substantially degraded by the SIF within 16 hours. Conclusion: The pronounced lability of the plant-derived allergens was thou ght to reflect the discrete sensitization and elicitation processes of pati ents with latex-fruit syndrome or oral allergy syndrome, These results indi cate that the allergenicity of a newly expressed protein should be carefull y evaluated according to not only its digestibility but also other importan t properties.