title: Effects of feeding Bt MON810 maize to pigs for 110 days on peripheral immune response and digestive fate of the cry1Ab gene and truncated Bt toxin.
abstract: BACKGROUND
  The objective of this study was to evaluate potential long-term (110 days) and age-specific effects of feeding genetically modified Bt maize on peripheral immune response in pigs and to determine the digestive fate of the cry1Ab gene and truncated Bt toxin.
  
  
  RESULTS
  Forty day old pigs (n = 40) were fed one of the following treatments: 1) isogenic maize-based diet for 110 days (isogenic); 2) Bt maize-based diet (MON810) for 110 days (Bt); 3) Isogenic maize-based diet for 30 days followed by Bt maize-based diet for 80 days (isogenic/Bt); and 4) Bt maize-based diet (MON810) for 30 days followed by isogenic maize-based diet for 80 days (Bt/isogenic). Blood samples were collected during the study for haematological analysis, measurement of cytokine and Cry1Ab-specific antibody production, immune cell phenotyping and cry1Ab gene and truncated Bt toxin detection. Pigs were sacrificed on day 110 and digesta and organ samples were taken for detection of the cry1Ab gene and the truncated Bt toxin. On day 100, lymphocyte counts were higher (P<0.05) in pigs fed Bt/isogenic than pigs fed Bt or isogenic. Erythrocyte counts on day 100 were lower in pigs fed Bt or isogenic/Bt than pigs fed Bt/isogenic (P<0.05). Neither the truncated Bt toxin nor the cry1Ab gene were detected in the organs or blood of pigs fed Bt maize. The cry1Ab gene was detected in stomach digesta and at low frequency in the ileum but not in the distal gastrointestinal tract (GIT), while the Bt toxin fragments were detected at all sites in the GIT.
  
  
  CONCLUSIONS
  Perturbations in peripheral immune response were thought not to be age-specific and were not indicative of Th 2 type allergenic or Th 1 type inflammatory responses. There was no evidence of cry1Ab gene or Bt toxin translocation to organs or blood following long-term feeding.
authors.affiliation: Teagasc, Pig Development Department, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, County Cork, Ireland.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Walsh
authors.forename: Stefan G
authors.initials: SG
authors.lastname: Buzoianu
authors.forename: Mary C
authors.initials: MC
authors.lastname: Rea
authors.forename: Orla
authors.initials: O
authors.lastname: O'Donovan
authors.forename: Eva
authors.initials: E
authors.lastname: Gelencsér
authors.forename: Gabriella
authors.initials: G
authors.lastname: Ujhelyi
authors.forename: R Paul
authors.initials: RP
authors.lastname: Ross
authors.forename: Gillian E
authors.initials: GE
authors.lastname: Gardiner
authors.forename: Peadar G
authors.initials: PG
authors.lastname: Lawlor
mesh_terms: D000375:Aging / Q000235:genetics / Q000276:immunology / Q000502:physiology; D000821:Animal Feed / Q000009:adverse effects*; D000818:Animals; D000917:Antibody Formation; D000918:Antibody Specificity; D001413:Bacillus thuringiensis / Q000235:genetics; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D001427:Bacterial Toxins / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004063:Digestion; D004731:Endotoxins / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D030841:Food, Genetically Modified / Q000009:adverse effects*; D006460:Hemolysin Proteins / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D007109:Immunity / Q000235:genetics*; D007136:Immunoglobulins / Q000096:biosynthesis / Q000276:immunology; D008297:Male; D030821:Plants, Genetically Modified / Q000009:adverse effects; D017384:Sequence Deletion; D013552:Swine / Q000276:immunology / Q000502:physiology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D003313:Zea mays / Q000235:genetics*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004731:Endotoxins; D006460:Hemolysin Proteins; D007136:Immunoglobulins; C030956:insecticidal crystal protein, Bacillus Thuringiensis