title: Investigations of immunogenic, allergenic and adjuvant properties of Cry1Ab protein after intragastric exposure in a food allergy model in mice.
abstract: In genetically modified (GM) crops there is a risk that the inserted genes may introduce new allergens and/or adjuvants into the food and feed chain. The MON810 maize, expressing the insecticidal Cry1Ab toxin, is grown in many countries worldwide. In animal models, intranasal and intraperitoneal immunisations with the purified Cry1Ab proteins have induced immune responses, and feeding trials with Cry1Ab-containing feed have revealed some altered immune responses. Previous investigations have primarily measured antibody responses to the protein, while investigations of clinical food allergy symptoms, or allergy promotion (adjuvant effect) associated with the Cry1Ab protein are largely missing. We aimed to investigate immunogenic, allergenic and adjuvant properties of purified Cry1Ab toxin (trypCry1Ab, i.e., trypsin activated Cry1Ab) in a mouse model of food allergy.
  
  
  
  Female C3H/HeJ mice were immunized by intragastric gavage of 10 μg purified, trypsin activated Cry1Ab toxin (trypCry1Ab) alone or together with the food allergen lupin. Cholera toxin was added as a positive control for adjuvant effect to break oral tolerance. Clinical symptoms (anaphylaxis) as well as humoral and cellular responses were assessed.
  
  
  
  In contrast to results from previous airway investigations, we observed no indication of immunogenic properties of trypCry1Ab protein after repeated intragastric exposures to one dose, with or without CT as adjuvant. Moreover, the results indicated that trypCry1Ab given by the intragastric route was not able to promote allergic responses or anaphylactic reactions against the co-administered allergen lupin at the given dose.
  
  
  
  The study suggests no immunogenic, allergenic or adjuvant capacity of the given dose of trypCry1Ab protein after intragastric exposure of prime aged mice.
authors.affiliation: GenØk - Centre for biosafety, Tromsø, Norway. monica.andreassen@fhi.no.|Norwegian Institute of Public Health, Oslo, Norway. monica.andreassen@fhi.no.|Present address: Department of Food, Water and Cosmetics, Norwegian Institute of Public Health, PO Box 4404, 0403, Oslo, Norway. monica.andreassen@fhi.no.
authors.forename: Monica
authors.initials: M
authors.lastname: Andreassen
authors.affiliation: GenØk - Centre for biosafety, Tromsø, Norway.|UiT The Arctic University of Norway, Tromsø, Norway.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bøhn
authors.affiliation: GenØk - Centre for biosafety, Tromsø, Norway.|North West University, Potchefstroom, South Africa.
authors.forename: Odd-Gunnar
authors.initials: OG
authors.lastname: Wikmark
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Johanna
authors.initials: J
authors.lastname: Bodin
authors.affiliation: GenØk - Centre for biosafety, Tromsø, Norway.|UiT The Arctic University of Norway, Tromsø, Norway.
authors.forename: Terje
authors.initials: T
authors.lastname: Traavik
authors.affiliation: Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Martinus
authors.initials: M
authors.lastname: Løvik
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Unni Cecilie
authors.initials: UC
authors.lastname: Nygaard
mesh_terms: D000485:Allergens / Q000276:immunology*; D000818:Animals; D001427:Bacterial Toxins / Q000276:immunology; D056931:Cryptochromes / Q000276:immunology* / Q000378:metabolism; D002523:Edible Grain; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D030841:Food, Genetically Modified; D007073:Immunoglobulin E / Q000378:metabolism; D019476:Insect Proteins / Q000276:immunology*; D007422:Intestines / Q000276:immunology* / Q000382:microbiology; D031297:Lupinus / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D030781:Organisms, Genetically Modified; D010936:Plant Extracts / Q000276:immunology*; D059748:Proteolysis; D014357:Trypsin / Q000378:metabolism; D003313:Zea mays / Q000235:genetics / Q000276:immunology*
chemical_list: D000485:Allergens; D001427:Bacterial Toxins; C538963:CRY1 protein, human; D056931:Cryptochromes; D019476:Insect Proteins; D010936:Plant Extracts; D007073:Immunoglobulin E; D014357:Trypsin
keywords: Anaphylaxis; Cry1Ab; Food allergy; Genetically modified maize; Mice