title: Interleukin-17 immunity in pediatric Crohn disease and ulcerative colitis.
abstract: OBJECTIVE
  The present understanding of inflammatory bowel disease pathogenesis mainly relies on studies of adult patients. Therefore, we studied the balance between T-effector and regulatory cells in pediatric inflammatory bowel disease.
  
  
  METHODS
  Quantitative polymerase chain reaction and immunohistochemistry served to quantify the expression of immunological markers in mucosal biopsies and flow cytometry analysis was used in peripheral blood mononuclear cells.
  
  
  RESULTS
  Colonic interleukin (IL)-17+, IL-22, and IL-6 mRNA upregulation and increase in the number of colonic IL-17 cells were demonstrated in both Crohn disease (CD) and ulcerative colitis (UC). Likewise, colonic forkhead box P3 (FOXP3+) mRNA expression and the number of colonic FOXP3 cells were increased both in CD and in UC and were accompanied in CD also with increased numbers of FOXP3+CD25 High CD4 cells in peripheral blood. Ileal relation of IL-17/CD4 cells was increased only in CD.
  
  
  CONCLUSIONS
  We showed activation of colonic IL-17/IL-22 axis and upregulation of FOXP3 to occur both in pediatric CD and in UC, indicating shared immunological characteristics. Upregulation of IL-17 was restricted to colon in UC, but existed in the ileum and in the colon in active CD.
authors: Department of Vaccination and Immune Protection, Immune Response Unit, National Institute for Health and Welfare, Helsinki, Finland. veeruska@sci.fi
authors: Veera
authors: V
authors: Hölttä
authors: Paula
authors: P
authors: Klemetti
authors: Harri M
authors: HM
authors: Salo
authors: Antti
authors: A
authors: Koivusalo
authors: Mikko
authors: M
authors: Pakarinen
authors: Mia
authors: M
authors: Westerholm-Ormio
authors: Kaija-Leena
authors: KL
authors: Kolho
authors: Outi
authors: O
authors: Vaarala
mesh_terms: D000293:Adolescent; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003093:Colitis, Ulcerative / Q000276:immunology* / Q000378:metabolism; D003106:Colon / Q000276:immunology* / Q000378:metabolism; D003424:Crohn Disease / Q000276:immunology* / Q000378:metabolism; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007082:Ileum / Q000276:immunology* / Q000378:metabolism; D020381:Interleukin-17 / Q000235:genetics / Q000378:metabolism*; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D007378:Interleukins / Q000235:genetics / Q000378:metabolism; D007413:Intestinal Mucosa / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D015854:Up-Regulation; D000097043:Interleukin-22
chemical_list: D051858:Forkhead Transcription Factors; D020381:Interleukin-17; D053645:Interleukin-2 Receptor alpha Subunit; D015850:Interleukin-6; D007378:Interleukins; D012333:RNA, Messenger; D000097043:Interleukin-22; C418974:FOXP3 protein, human