title: Increased frequencies of IL-31-producing T cells are found in chronic atopic dermatitis skin.
abstract: Interleukin (IL)-31 has been associated with pruritus, a characteristic feature of atopic dermatitis (AD). Local T cell responses may be responsible for the increased level of IL-31 mRNA observed in AD. We investigated the frequency of IL-31-producing T cells in AD lesions, as well as their cytokine profile. T cells were isolated from chronic AD lesions, autologous blood and healthy donor skin. Intracellular expression of IL-31, IFN-γ, IL-13, IL-17 and IL-22 was measured using flow cytometry. T cells from AD lesions contained significantly higher percentages of IL-31-producing T cells compared to autologous blood and donor skin. Many IL-31-producing T cells co-produced IL-13 and to lesser extent IL-22, but rarely IFN-γ or IL-17. A substantial part of the IL-31-producing T cells did not co-produce any of the other cytokines and could therefore not be linked to any of the known functionally different T cell subsets. The T cell infiltrates were also relatively enriched for Th2/Tc2 and Th22/Tc22 cells, while frequencies of Th1/Tc1 and Th17 cells were decreased. This is the first report describing the detection of IL-31 at protein level in skin-infiltrating T cells. We show here that T cells in chronic AD skin produce IL-31 and that AD lesions contain increased levels of these IL-31-producing T cells. This suggests that a substantial part of previously reported increased IL-31 mRNA levels in AD skin is T cell derived and that these cells may be involved in the pathogenesis of AD.
authors.affiliation: Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Krisztina
authors.initials: K
authors.lastname: Szegedi
authors.forename: Andreas E
authors.initials: AE
authors.lastname: Kremer
authors.forename: Sanja
authors.initials: S
authors.lastname: Kezic
authors.forename: Marcel B M
authors.initials: MB
authors.lastname: Teunissen
authors.forename: Jan D
authors.initials: JD
authors.lastname: Bos
authors.forename: Rosalie M
authors.initials: RM
authors.lastname: Luiten
authors.forename: Pieter C
authors.initials: PC
authors.lastname: Res
authors.forename: Maritza A
authors.initials: MA
authors.lastname: Middelkamp-Hup
mesh_terms: D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism*; D003876:Dermatitis, Atopic / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007378:Interleukins / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000276:immunology; D055815:Young Adult
chemical_list: C573415:IFNG protein, human; C502187:IL31 protein, human; D007378:Interleukins; D007371:Interferon-gamma