BACKGROUND: In a recent murine study, we showed that impaired gastric digestion supports the induction of fish allergy by protecting the digestion-sensitive major allergen parvalbumin and thus enhancing its sensitizing properties. OBJECTIVE: The aim of the present study was to investigate whether impairment of peptic degradation might also play a role in the effector phase of codfish allergy. METHODS: The resistance of cod proteins to digestion by simulated gastric fluid was assessed in vitro . Gastric solutions with pH values ranging from 1.25 to 5.0 were prepared, and the influence of the pH on protein degradation was evaluated by means of SDS-PAGE and IgE immunoblotting. The allergenic potency of digested and undigested cod extract was further characterized in RAST inhibition and basophil histamine release experiments. RESULTS: The digestion experiments revealed that codfish proteins were degraded within 1 minute under physiologic gastric conditions. An only marginal pH shift from 2.5 to 2.75 abrogated completely the digestion of cod allergens. In RAST inhibition experiments digested cod extracts showed a reduced IgE-binding capability that was dependent on the digestion time. Moreover, peptic fragments expressed a 10,000 times reduced allergenic potency, as evaluated on the basis of histamine release from human basophils. CONCLUSION: Codfish allergens have a grossly reduced ability to trigger an intestinal allergic reaction when they are physiologically degraded. Impairment of the physiologic digestion might thus lower the threshold levels of a food allergen in sensitized patients.
BACKGROUND: In a recent murine study, we showed that impaired gastric digestion supports the induction of fish allergy by protecting the digestion-sensitive major allergen parvalbumin and thus enhancing its sensitizing properties. OBJECTIVE: The aim of the present study was to investigate whether impairment of peptic degradation might also play a role in the effector phase of codfish allergy. METHODS: The resistance of cod proteins to digestion by simulated gastric fluid was assessed in vitro . Gastric solutions with pH values ranging from 1.25 to 5.0 were prepared, and the influence of the pH on protein degradation was evaluated by means of SDS-PAGE and IgE immunoblotting. The allergenic potency of digested and undigested cod extract was further characterized in RAST inhibition and basophil histamine release experiments. RESULTS: The digestion experiments revealed that codfish proteins were degraded within 1 minute under physiologic gastric conditions. An only marginal pH shift from 2.5 to 2.75 abrogated completely the digestion of cod allergens. In RAST inhibition experiments digested cod extracts showed a reduced IgE-binding capability that was dependent on the digestion time. Moreover, peptic fragments expressed a 10,000 times reduced allergenic potency, as evaluated on the basis of histamine release from human basophils. CONCLUSION: Codfish allergens have a grossly reduced ability to trigger an intestinal allergic reaction when they are physiologically degraded. Impairment of the physiologic digestion might thus lower the threshold levels of a food allergen in sensitized patients.
Authors: David C Dallas; Megan R Sanctuary; Yunyao Qu; Shabnam Haghighat Khajavi; Alexandria E Van Zandt; Melissa Dyandra; Steven A Frese; Daniela Barile; J Bruce German Journal: Crit Rev Food Sci Nutr Date: 2017-10-13 Impact factor: 11.176
Authors: I Pali-Schöll; R Herzog; J Wallmann; K Szalai; R Brunner; A Lukschal; P Karagiannis; S C Diesner; E Jensen-Jarolim Journal: Clin Exp Allergy Date: 2010-03-04 Impact factor: 5.018
Authors: Eva Untersmayr; Helle Vestergaard; Hans-Jørgen Malling; Louise Bjerremann Jensen; Michael H Platzer; George Boltz-Nitulescu; Otto Scheiner; Per Stahl Skov; Erika Jensen-Jarolim; Lars K Poulsen Journal: J Allergy Clin Immunol Date: 2007-01-09 Impact factor: 10.793
Authors: Harmen H J de Jongh; Carlos López Robles; Eefjan Timmerman; Julie A Nordlee; Poi-Wah Lee; Joseph L Baumert; Robert G Hamilton; Steve L Taylor; Stef J Koppelman Journal: Biomed Res Int Date: 2013-06-26 Impact factor: 3.411