title: Increased numbers of FoxP3-expressing CD4+ CD25+ regulatory T cells in peripheral blood from dogs with atopic dermatitis and its correlation with disease severity.
abstract: BACKGROUND
  Atopic dermatitis (AD) is a common chronic inflammatory skin disease of humans and dogs. Regulatory T cells (Tregs) are essential controllers of immune homeostasis and have been shown to play a key role in human AD, even though frequencies of Tregs in atopic human patients vary greatly. Only two studies have reported Treg numbers in the peripheral blood of dogs with canine AD (CAD).
  
  
  OBJECTIVE
  This study aimed to assess the numbers of circulating Tregs in healthy and atopic dogs, and to determine whether Treg numbers correlate with age, sex, disease severity or pre-treatment.
  
  
  METHODS
  Client-owned dogs including 14 healthy dogs and 35 dogs with CAD.
  
  
  METHODS
  Expression of Tregs in peripheral blood mononuclear cells was evaluated by flow cytometry. Tregs were phenotypically identified as T cells triple positive for CD4, CD25 and FoxP3.
  
  
  RESULTS
  The percentage of circulating CD4(+)  CD25(+)  FoxP3(+) Tregs in atopic dogs was increased significantly compared to healthy dogs (mean 2.1% versus 1%, P = 0.002) and correlated with disease severity (Pruritus Scale: r = 0.48, P = 0.003; CADESI-04: r = 0.34, P = 0.044). No significant differences in age or sex were found in either group and pre-treatment had no influence on results for atopic dogs.
  
  
  CONCLUSIONS
  Data suggest that, as in humans, CD4(+)  CD25(+)  FoxP3(+) Tregs may contribute to the pathogenesis of CAD as indicated by an association between Treg frequency and disease severity. Further investigation is required to improve the understanding of the role of Tregs in atopic dogs.
authors.affiliation: Dermatology Unit, Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
authors.forename: Verena
authors.initials: V
authors.lastname: Hauck
authors.affiliation: Clinic for Small Animal Surgery, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Hügli
authors.affiliation: Clinical Laboratory and Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
authors.forename: Marina L
authors.initials: ML
authors.lastname: Meli
authors.affiliation: Dermatology Unit, Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
authors.forename: Ana
authors.initials: A
authors.lastname: Rostaher
authors.affiliation: Dermatology Unit, Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
authors.forename: Nina
authors.initials: N
authors.lastname: Fischer
authors.affiliation: Clinical Laboratory and Center for Clinical Studies, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
authors.forename: Regina
authors.initials: R
authors.lastname: Hofmann-Lehmann
authors.affiliation: Dermatology Unit, Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
authors.forename: Claude
authors.initials: C
authors.lastname: Favrot
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D003876:Dermatitis, Atopic / Q000097:blood / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000276:immunology*; D004285:Dogs; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D053645:Interleukin-2 Receptor alpha Subunit / Q000235:genetics / Q000378:metabolism*; D008297:Male
chemical_list: D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit