title: CD4(+) T cells producing interleukin (IL)-17, IL-22 and interferon-γ are major effector T cells in nickel allergy.
abstract: BACKGROUND
  It has been suggested that interleukin (IL)-17 and IL-22 play important roles in the elicitation of human allergic contact dermatitis; however, the frequencies of T cell subtypes producing IL-17 and IL-22 in human allergic contact dermatitis are unknown.
  
  
  OBJECTIVE
  To determine the frequencies of CD4(+) , CD8(+) and γδ T cells producing IL-17, IL-22 and interferon (IFN)-γ in the blood and skin from nickel-allergic patients.
  
  
  METHODS
  Blood samples were collected from 14 patients and 17 controls, and analysed by flow cytometry. Biopsies were taken from 5 patients and 6 controls, and analysed by immunohistochemistry and flow cytometry of skin lymphocytes.
  
  
  RESULTS
  We found an increased frequency of γδ T cells in the blood, but no differences in the distribution of cytokine-producing CLA(+) T cell subtypes in nickel-allergic patients as compared with controls. In nickel-allergic patients, there was massive cellular infiltration dominated by CD4(+) T cells producing IL-17, IL-22 and IFN-γ in nickel-challenged skin but not in vehicle-challenged skin.
  
  
  CONCLUSIONS
  CD4(+) T cells producing IL-17, IL-22 and IFN-γ are important effector cells in the eczematous reactions of nickel-induced allergic contact dermatitis in humans.
authors.affiliation: Department of International Health, Immunology and Microbiology, University of Copenhagen, DK-2200 Copenhagen, Denmark.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Dyring-Andersen
authors.forename: Lone
authors.initials: L
authors.lastname: Skov
authors.forename: Marianne B
authors.initials: MB
authors.lastname: Løvendorf
authors.forename: Michael
authors.initials: M
authors.lastname: Bzorek
authors.forename: Knud
authors.initials: K
authors.lastname: Søndergaard
authors.forename: Jens-Peter H
authors.initials: JP
authors.lastname: Lauritsen
authors.forename: Sally
authors.initials: S
authors.lastname: Dabelsteen
authors.forename: Carsten
authors.initials: C
authors.lastname: Geisler
authors.forename: Charlotte Menné
authors.initials: CM
authors.lastname: Bonefeld
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D016022:Case-Control Studies; D017449:Dermatitis, Allergic Contact / Q000209:etiology / Q000276:immunology* / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000378:metabolism*; D020381:Interleukin-17 / Q000378:metabolism*; D007378:Interleukins / Q000378:metabolism*; D018655:Lymphocyte Count; D009532:Nickel / Q000009:adverse effects / Q000276:immunology*; D012867:Skin / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000378:metabolism; D000097043:Interleukin-22
chemical_list: D015415:Biomarkers; D007371:Interferon-gamma; D020381:Interleukin-17; D007378:Interleukins; D009532:Nickel; D000097043:Interleukin-22