title: Regional Specialisation of T Cell Subsets and Apoptosis in the Human Gut Mucosa: Differences Between Ileum and Colon in Healthy Intestine and Inflammatory Bowel Diseases.
abstract: OBJECTIVE
  There is very limited information regarding region-specific immunological response in human intestine. We aimed to determine differences in immune compartmentalisation between ileum and colon in healthy and inflamed mucosa.
  
  
  METHODS
  T cell profile and its apoptosis were measured by flow cytometry, Th1, Th17, Treg [CD4(+)CD25(+)FOXP3(+)], double positive [DP, CD3(+)CD4(+)CD8(+)] and double negative T cells [DN, CD3(+)CD4(-)CD8(-)], immunohistochemistry [FOXP3, caspase-3], and real-time polymerase chain reaction [PCR] [IFN-γ, IL-17-A, and FOXP3] on biopsies from different regions of healthy intestine and of intestine in inflammatory bowel diseases.
  
  
  RESULTS
  Healthy colon showed higher percentages of Treg, Th17, and DN, and lower numbers of DP T cells compared with ileum [p < 0.05]. Some but not all region-specific differences were lost in inflammatory conditions. Disease-specific patterns were found: a Th1/Th17 pattern and a Th17 pattern in Crohn's disease and ulcerative colitis respectively, whereas a reduction in Th1/Th17 was found in microscopic colitis. In colonic Crohn's disease and microscopic colitis, DN T cells had a pattern inverse to that of Th1/Th17 (increase in microscopic colitis [p < 0.05] and decrease in Crohn's disease [p < 0.005]). Higher levels of lymphocyte apoptosis were found in healthy colon compared with the ileal counterparts [p = 0.001]. All forms of colonic inflammation presented a dramatic decrease in apoptosis compared with healthy colon. By contrast ileal Crohn's disease showed higher levels of cleaved-Caspase(+) CD3(+) cells.
  
  
  CONCLUSIONS
  Immunological differences exist in healthy gastrointestinal tract. Inflammatory processes overwhelm some location-specific differences, whereas others are maintained. Care has to be taken when analysing immune response in intestinal inflammation, as location-specific differences may be relevant.
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Carrasco
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Fernández-Bañares
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Pedrosa
authors.affiliation: Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain Department of Pathology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Salas
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain.
authors.forename: Carme
authors.initials: C
authors.lastname: Loras
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain.
authors.forename: Mercè
authors.initials: M
authors.lastname: Rosinach
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Aceituno
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Andújar
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Forné
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain.
authors.forename: Yamile
authors.initials: Y
authors.lastname: Zabana
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Universitat de Barcelona, Catalonia, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas [CIBERehd], Barcelona, Catalonia, Spain mestevecomas@telefonica.net.
authors.forename: Maria
authors.initials: M
authors.lastname: Esteve
mesh_terms: D000328:Adult; D000368:Aged; D017209:Apoptosis / Q000276:immunology*; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D003106:Colon / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007082:Ileum / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction; D016176:T-Lymphocyte Subsets / Q000378:metabolism*
chemical_list: D015415:Biomarkers
keywords: Intestinal compartmentalization; apoptosis; intestinal lymphocytes