title: Cry1Ab protein from Bacillus thuringiensis and MON810 cry1Ab-transgenic maize exerts no adjuvant effect after airway exposure.
abstract: The genetically modified (GM) maize event MON810 has been inserted with a processed version of the transgene, cry1Ab, derived from the soil bacterium Bacillus thuringiensis (Bt) to express proteins with insecticidal properties. Such proteins may introduce new allergens and also act as adjuvants that promote allergic responses. While focus has been on safe consumption and hence the oral exposure to GM food and feed, little is known regarding inhalation of pollen and desiccated airborne plant material from GM crops. The aim of this study was to investigate whether plant material from the Cry1Ab-expressing maize variety MON810, or trypsin-activated Cry1Ab (trypCry1Ab) protein produced in recombinant bacteria, may act as adjuvants against the allergen ovalbumin (OVA) in a mouse model of airway allergy. A clear proallergic adjuvant effect of the mucosal adjuvant cholera toxin (CT) was demonstrated, determined as increased specific IgE, eosinophils and Th2 cytokines in MLN cell supernates, while no elevation in OVA-specific antibodies or cytokine release from MLN cells after stimulation with OVA were observed in mice receiving Cry1Ab-containing plant materials or the trypCry1Ab protein. Our data suggest that Cry1Ab proteins had no detectable systemic adjuvant effect in mice after airway exposure. Further experiments with purified plant proteins, as well as long-term exposures needs be conducted to further evaluate exposures experienced in real-life situations.
authors.affiliation: GenØk - Centre for Biosafety, Tromsø, Norway; Norwegian Institute of Public Health, Oslo, Norway; UiT The Arctic University of Norway, Tromsø, Norway.
authors.forename: M
authors.initials: M
authors.lastname: Andreassen
authors.forename: T
authors.initials: T
authors.lastname: Bøhn
authors.forename: O-G
authors.initials: OG
authors.lastname: Wikmark
authors.forename: J
authors.initials: J
authors.lastname: Van den Berg
authors.forename: M
authors.initials: M
authors.lastname: Løvik
authors.forename: T
authors.initials: T
authors.lastname: Traavik
authors.forename: U C
authors.initials: UC
authors.lastname: Nygaard
mesh_terms: D000276:Adjuvants, Immunologic / Q000235:genetics / Q000494:pharmacology*; D000485:Allergens / Q000276:immunology; D000818:Animals; D000906:Antibodies / Q000097:blood; D001413:Bacillus thuringiensis / Q000235:genetics; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000494:pharmacology*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002772:Cholera Toxin / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D004731:Endotoxins / Q000235:genetics* / Q000494:pharmacology*; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006460:Hemolysin Proteins / Q000235:genetics* / Q000494:pharmacology*; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000276:immunology; D007306:Insecticides / Q000494:pharmacology; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D016254:Mutagenesis, Insertional / Q000235:genetics; D009504:Neutrophils / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology; D010940:Plant Proteins / Q000235:genetics; D011897:Random Allocation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D018418:Th2 Cells / Q000276:immunology; D014357:Trypsin / Q000378:metabolism; D003313:Zea mays / Q000235:genetics / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D000485:Allergens; D000906:Antibodies; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D016207:Cytokines; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D007073:Immunoglobulin E; D010047:Ovalbumin; D002772:Cholera Toxin; D014357:Trypsin