title: CD8(+) T cells in the lesional skin of atopic dermatitis and psoriasis patients are an important source of IFN-γ, IL-13, IL-17, and IL-22.
abstract: Although CD4(+) T cells are known to contribute to the pathology of atopic dermatitis (AD) and psoriasis, the role of CD8(+) T cells in these diseases remains poorly characterized. The aim of this study was to characterize the cytokine production of T cells from AD and psoriasis skin. We found that CD4(+) T cells isolated from AD skin were largely Th2 (T helper type 2) biased, in agreement with prior reports. However, we also observed large numbers of CD8(+) T cells producing IL-13, IFN-γ, and IL-22. We observed increased numbers of CD8(+) T cells isolated from AD skin, and immunohistochemistry studies confirmed the presence of CD8(+) T cells in the dermis and epidermis of AD skin lesions. Surprisingly, T-cell cytokine production was similar in the lesional and nonlesional skin of patients with AD. T cells from psoriatic lesional skin predominantly produced IFN-γ, IL-17, and IL-22, in agreement with prior studies. However, in addition to Th17 cells, we observed high percentages of CD8(+) T cells that produced both IL-22 and IL-17 in psoriatic skin lesions. Our findings demonstrate that CD8(+) T cells are a significant and previously unappreciated source of inflammatory cytokine production in both AD and psoriasis.
authors.affiliation: Department of Dermatology, University Medical Center Utrecht, Utrecht, The Netherlands. dirkjanhijnen@gmail.com
authors.forename: Dirkjan
authors.initials: D
authors.lastname: Hijnen
authors.forename: Edward F
authors.initials: EF
authors.lastname: Knol
authors.forename: Yoony Y
authors.initials: YY
authors.lastname: Gent
authors.forename: Barbara
authors.initials: B
authors.lastname: Giovannone
authors.forename: Scott J P
authors.initials: SJ
authors.lastname: Beijn
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Kupper
authors.forename: Carla A F M
authors.initials: CA
authors.lastname: Bruijnzeel-Koomen
authors.forename: Rachael A
authors.initials: RA
authors.lastname: Clark
mesh_terms: D000328:Adult; D000368:Aged; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D016764:Cell Polarity / Q000276:immunology; D002478:Cells, Cultured; D003876:Dermatitis, Atopic / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology* / Q000378:metabolism; D018793:Interleukin-13 / Q000276:immunology* / Q000378:metabolism; D020381:Interleukin-17 / Q000276:immunology* / Q000378:metabolism; D007378:Interleukins / Q000276:immunology* / Q000378:metabolism; D008875:Middle Aged; D011565:Psoriasis / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D055815:Young Adult; D000097043:Interleukin-22
chemical_list: D007371:Interferon-gamma; D018793:Interleukin-13; D020381:Interleukin-17; D007378:Interleukins; D000097043:Interleukin-22; C578095:IL13 protein, human; C508717:IL17A protein, human