title: TH1 and TH17 interactions in untreated inflamed mucosa of inflammatory bowel disease, and their potential to mediate the inflammation.
abstract: BACKGROUND
  Crohn's disease (CD) and ulcerative colitis (UC) have been associated with a T helper1 (TH1) and a TH2 cytokine profile, respectively. Recently, a TH17 lineage has been introduced, but their role in the inflammation of CD and UC is not fully understood.
  
  
  OBJECTIVE
  To characterize the cytokines directing the TH17 cells and their interactions with TH1 cells in the mucosa of untreated patients with CD and UC.
  
  
  METHODS
  Seventy-nine patients with untreated UC, 32 patients with untreated CD and 23 controls with no signs of colon disease were included in the study. Clinical indices for ulcerative colitis (UCDAI) and Crohn's disease (CDAI) were assessed. Biopsies for measurements of interleukin (IL)-17A, IL-23, IL-6, transforming growth factor-beta (TGF-β), interferon-gamma (IFN-γ), mRNA levels as well as immunohistochemical (IHC) analyses were performed.
  
  
  RESULTS
  The gene expression for all cytokines in UC and for all cytokines except for TGF-β in CD were significantly increased compared with the controls. The immunohistochemical analysis showed significantly increased number of IL-17A positive cells in lamina propria and epithelium of both UC and CD compared to controls. The levels of IL-17A and IL-23 mRNA were significantly higher in UC than in CD while the levels of IL-6 were significantly higher in CD compared with UC. The levels of IL-17A, IL-6 and IL-23 mRNA were associated with the disease activity score in both UC and CD. IFN-γ was associated with the disease activity in UC, but did not reach significant level in CD.
  
  
  CONCLUSIONS
  Increased levels of IL-17A and IL-23 were found in both UC and CD compared to controls. Association to the grade of inflammation and clinical activity was also observed. IL-17A and IL-23 were significantly higher in UC than in CD. TH1 and TH17 cytokines seem to act synergistically in inflammatory bowel disease (IBD) with no apparent polarization between UC and CD.
authors.affiliation: Laboratory of Gastroenterology, Institute of Clinical Medicine, University of Tromsø, and Department of Medical Gastroenterology, University Hospital of Northern Norway, 9037 Tromsø, Norway. trine.olsen@fagmed.uit.no
authors.forename: Trine
authors.initials: T
authors.lastname: Olsen
authors.forename: Renathe
authors.initials: R
authors.lastname: Rismo
authors.forename: Guanglin
authors.initials: G
authors.lastname: Cui
authors.forename: Rasmus
authors.initials: R
authors.lastname: Goll
authors.forename: Ingrid
authors.initials: I
authors.lastname: Christiansen
authors.forename: Jon
authors.initials: J
authors.lastname: Florholmen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002450:Cell Communication / Q000276:immunology*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D003710:Demography; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000150:complications / Q000276:immunology / Q000473:pathology*; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis / Q000276:immunology* / Q000473:pathology* / Q000628:therapy; D007413:Intestinal Mucosa / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology* / Q000473:pathology; D058504:Th17 Cells / Q000276:immunology* / Q000473:pathology; D055815:Young Adult
chemical_list: D016207:Cytokines; D012333:RNA, Messenger