title: IFN-gamma-inducible expression of thymus and activation-regulated chemokine/CCL17 and macrophage-derived chemokine/CCL22 in epidermal keratinocytes and their roles in atopic dermatitis.
abstract: Thymus and activation-regulated chemokine (TARC)/CCL17 and macrophage-derived chemokine (MDC)/CCL22 are a pair of CC chemokines known to selectively attract T(h)2 type memory T cells via CCR4. Here we examined circulating levels of TARC and MDC in patients with atopic dermatitis (AD) and control subjects by using plasma samples, which reflect blood contents of chemokines more accurately than serum samples. The plasma levels of TARC and MDC were significantly elevated in AD patients. These values also strongly correlated with disease severity and serum lactate dehydrogenase levels, and weakly correlated with serum total IgE levels and blood eosinophilia. Previous studies demonstrated TARC immunoreactivity in the epidermal layer of AD lesional skin and production of TARC by a human keratinocytic cell line HaCaT upon stimulation with IFN-gamma. Here we demonstrated MDC immunoreactivity in the epidermal layer of AD skin at levels stronger than that of TARC. Furthermore, primary epidermal keratinocytes expressed both TARC and MDC mRNA upon stimulation with IFN-gamma, but efficiently secreted only MDC. These results suggest a post-transcriptional regulation in TARC production. IFN-gamma also induced TARC and MDC mRNA in mouse skin. Collectively, both TARC and MDC play important roles in the local accumulation of T(h)2 cells in AD lesional skin. Production of T(h)2-attracting chemokines by epidermal keratinocytes upon treatment with IFN-gamma, which is also the potent inducer of T(h)1-attracting chemokines, may underline the pivotal role of IFN-gamma in the chronic phase of AD where both T(h)1 and T(h)2 responses are mixed.
authors.affiliation: Division of Dermatology, Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Horikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakayama
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hikita
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Yamada
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Fujisawa
authors.forename: Toshinori
authors.initials: T
authors.lastname: Bito
authors.forename: Susumu
authors.initials: S
authors.lastname: Harada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fukunaga
authors.forename: David
authors.initials: D
authors.lastname: Chantry
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Gray
authors.forename: Atsushi
authors.initials: A
authors.lastname: Morita
authors.forename: Ryuji
authors.initials: R
authors.lastname: Suzuki
authors.forename: Tadashi
authors.initials: T
authors.lastname: Tezuka
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Ichihashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Yoshie
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002478:Cells, Cultured; D054414:Chemokine CCL17; D054422:Chemokine CCL22; D019742:Chemokines, CC / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D003876:Dermatitis, Atopic / Q000097:blood / Q000276:immunology*; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D015603:Keratinocytes / Q000276:immunology*; D007770:L-Lactate Dehydrogenase / Q000097:blood; D007958:Leukocyte Count; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C106230:CCL17 protein, human; C515482:CCL22 protein, human; C499538:Ccl17 protein, mouse; C515483:Ccl22 protein, mouse; D054414:Chemokine CCL17; D054422:Chemokine CCL22; D019742:Chemokines, CC; D012333:RNA, Messenger; D007371:Interferon-gamma; D007770:L-Lactate Dehydrogenase