title: Colonoscopy and µPET/CT are valid techniques to monitor inflammation in the adoptive transfer colitis model in mice.
abstract: BACKGROUND
  Preclinical in vivo research on inflammatory bowel diseases requires proper animal models and techniques allowing longitudinal monitoring of colonic inflammation without the need to kill animals. We evaluated colonoscopy and μ-positron emission tomography/computed tomography (μPET/CT) as monitoring tools in a model for chronic colitis in mice.
  
  
  METHODS
  Colitis was induced by adoptive transfer of CD4(+)CD25(-)CD62L(+) T cells in immunocompromised severe combined immunodeficient mice. Three study protocols were designed. In study 1, colonoscopy and µPET/CT were performed once, 4 weeks after transfer. In study 2 and study 3, colitis was sequentially followed up through colonoscopy (study 2) or colonoscopy plus µPET/CT (study 3). Each study included postmortem evaluation of colonic inflammation (macroscopy, microscopy, and myeloperoxidase activity).
  
  
  RESULTS
  In study 1, both colonoscopy and µPET/CT detected colitis 4 weeks after transfer. Study 2 showed a gradual increase in colonoscopic score from week 2 (1.4 ± 0.6) to week 8 (6.0 ± 1.1). In study 3, colitis was detected 2 weeks after transfer by µPET/CT (2.0 ± 0.4) but not by colonoscopy, whereas both techniques detected inflammation 4 and 6 weeks after transfer. Colonoscopy correlated with µPET/CT (r = 0.812, 0.884, and 0.781, respectively) and with postmortem analyses in all 3 studies.
  
  
  CONCLUSIONS
  Adoptive transfer of CD4(+)CD25(-)CD62L(+) T cells in severe combined immunodeficient mice results in a moderate chronic colitis. Evolution of colitis could be monitored over time by both colonoscopy and µPET/CT. µPET/CT seems to detect inflammation at an earlier time point than colonoscopy. Both techniques represent reliable and safe methods without the need to kill animals.
authors: Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium.
authors: Marthe
authors: M
authors: Heylen
authors: Steven
authors: S
authors: Deleye
authors: Joris G
authors: JG
authors: De Man
authors: Nathalie E
authors: NE
authors: Ruyssers
authors: Wim
authors: W
authors: Vermeulen
authors: Sigrid
authors: S
authors: Stroobants
authors: Paul A
authors: PA
authors: Pelckmans
authors: Tom G
authors: TG
authors: Moreels
authors: Steven
authors: S
authors: Staelens
authors: Benedicte Y
authors: BY
authors: De Winter
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003092:Colitis / Q000175:diagnosis* / Q000276:immunology; D003113:Colonoscopy; D004195:Disease Models, Animal; D005260:Female; D007249:Inflammation / Q000175:diagnosis* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D009195:Peroxidase / Q000378:metabolism; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
chemical_list: D009195:Peroxidase