２２回日本研究皮膚科学会総会・抄録

２２回日本研究皮膚科学会総会・抄録

-7- Immunology(2) 9/4 Room-A
EXPRESSION OF IL-15 BY HUMAN SQUAMOUS CARCINOMA CELL LINE CELLS IS UP-REGULATED BY IFN-g AND INHIBITED BY DEXAMETHASONE.
Gangwen Han, Keiji Iwatsuki, Masayuki Inoue, Takashi Matsui and Fumio Kaneko.
Department of Dermatology, Fukushima Medical College, Fukushima, Japan.
IL-15 is a newly described cytokine that shares many biological activities with IL-2. Previous studies demonstrated that keratinocytes express IL-15 which might be involved in T-cell-mediated cutaneous diseases. We screened the expression of IL-15 in various cell types by RT-PCR, and further investigated the effects of IFN-γ, cyclosporin A (CsA), and dexamethasone on IL-15 expression by human squamous carcinoma cell line (HSC) cells using northern hybridization. High doses of IFN-γ increased the expression of IL-15 by HSC, whereas dexamethasone completely inhibited the expression at a concentration of 10-6 M. In contrast, CsA has no effect on the expression at a concentration of 1μg/ml. These findings suggest that anti-inflammatory effects of dexamethasone may partly be caused by inhibition of keratinocyte-derived IL-15.

-8- Immunology(2) 9/4 Room-A
INTERLEUKIN (IL)-1a AND INTERFERON-g INDUCE TUMOR NECROSIS FACTOR (TNF)-a PRODUCTION FROM HUMAN KERATINOCYTES.
Kyoko Matsuura, Hiroshi Fujisawa, Fujio Otsuka.
Department of Dermatology, University of Tsukuba, Tsukuba, Japan.
INTERLEUKIN (IL)-1a AND INTERFERON-g INDUCE TUMOR NECROSIS FACTOR (TNF)-a PRODUCTION FROM HUMAN KERATINOCYTES K. Matsuura, H. Fujisawa, F. Otsuka. Department of Dermatology, University of Tsukuba, Tsukuba, Japan. Tumor necrosis factor-a (TNF-a) is a proinflammatory cytokine and known to be produced by a wide variety of cells including human keratinocytes (KCs). Altough ultraviolet B and lipopolysaccharide are known to induce TNF-a production from human KCs, what types of cytokines induce TNF-a production was unclear. In the present study, we have demonstrated that interleukin (IL)-1a and interferon (IFN)-g induced TNF-a, but no induction of TNF-a was observed with either IFN-a or IFN-a.　　Combined treatment with IL-1a and IFN-g induced TNF-a production synergistically. These results suggest that IL-1a and IFN-g are a positive regulator for the production of TNF-a from human KCs and likely has an augmentative effect on skin inflammation.

-9- Immunology(2) 9/4 Room-A
THE EFFECTS OF INTERFERONS ON INTERLEUKIN(IL)-6 AND IL-8 PRODUCTION FROM HUMAN KERATINOCYTES.
Hiroshi Fujisawa, Kyoko Matuura, Fujio Otsuka.
Department of Dermatology, University of Tsukuba, Tsukuba, Japan.
THE EFFECTS OF INTERFERONS ON INTERLEUKIN(IL)-6 AND IL-8 PRODUCTION FROM HUMAN KERATINOCYTES. H. Fujisawa, K. Matsuura, F. Otsuka. Deparetment of Dermatology, University of Tsukuba, Tsukuba, Japan. Interferons (IFNs)　have pleiotrophic effects including the ability to induce interleukin (IL)-6 and IL-8 productions in several cell types. IL-6 and IL-8 are proinflammatory cytokines and known to be produced by a wide variety of cells including human keratinocytes. In the present study, we sought to examine the effects of IFNs on IL-6 and IL-8 production from human keratinocytes. IFN-g induced IL-6 and IL-8 production dose-dependently, but no induction of IL-6 or IL-8 was observed with either IFN-a or IFN-b.　　Combined treatment with IFN-g and IL-1a induced 6-7-fold higher levels of IL-6 than IL-1a alone. Combined treatment with IFN-g and TNF-a induced 11-12-fold higher levels than TNF-a alone. The same treatments induced 3-4-fold higher levels of IL-8 in both cases. These results suggest that IFN-g is a positive regulator for the production of IL-6 and IL-8 from human keratinocytes and likely has an augmentative effect on skin inflammation.

-10- Immunology(2) 9/4 Room-A
INDUCTION OF INTERLEUKIN 1 RECEPTOR ANTAGONIST IN KERATINOCYTES BY INFLAMMATORY CYTOKINES.
Tetsuji Hirao, Hiroe Aoki, Yoshihisa Sato.
Institute for Advanced Skin Research Inc./Shiseido Research Center, Yokohama, Japan.
We have previously reported that content of IL-1 receptor antagonist (IL-1ra) is markedly elevated in the stratum corneum of sun-exposed area, UV-irradiated area, and various inflammatory skin disorders. The purpose of this study is to examine the involvement of inflammatory cytokines on induction of an anti-inflammatory cytokine, IL-1ra, in keratinocytes. Human keratinocytes, which were cultivated in the presence of mitomycin C-treated 3T3-J2 feeder layer, were treated with various cytokines, including IL-1a, b, TNF-a, TGF-a, b, and IFN-g. Contents of IL-1ra in keratinocytes were examined by Western blotting or ELISA. IL-1ra expression was enhanced markedly by IFN-g, and moderately by IL-1a, b, and TNF-a, but not by TGF-a and b. These results suggest that inflammatory cytokines produced by keratinocytes or infiltrating leukocytes can induce IL-1ra in keratinocytes. Induction of IL-1ra in keratinocytes by inflammatory cytokines may reflect a homeostatic response of the skin against various stimuli.

-11- Immunology(2) 9/4 Room-A
EFFECT OF AGiNG AND PHOTOAGiNG ON THE PRODUCTION AND EXPRESSION OF IL-1a AND IL-1 RECEPTOR ANTAGONIST IN RESPONSE TO SKiN IRRITANTS.
Dae Hun Suh, Hee Chul Eun, Jai Il Youn.
Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.
Skin aging can be separately considered into photoaging and chronological aging. In spite of the expectation that there must be large difference in the response pattern to irritants, there has been no report to investigate skin aging by comparing production and expression of cytokines in response to various stimuli. This study was done to know the change of the production and expression of IL-1a and IL-1 receptor antagonist (IL-1ra) according to age groups with the treatment of UVB, TPA and SLS. Monolayer keratinocyte cultures were performed using the skin from newborn, young adults and aged volunteers. Production of cytokines by ELISA were generally decreased with the increase of age. IL-1ra production from forearm skin was significantly reduced compared with that from thigh skin. The cytokine production ratio of irritants-treated group to age-matched control group showed the decrease in case of IL-1ra, according to skin aging. These ratios were sometimes significantly different between forearm and thigh. The results of mRNA expressions by RT-PCR were diverse. These results indicated that the response patterns with skin aging were various according to the kinds of stimuli. They also suggested that photoaged skin and chronologically aged skin are much different in the production and expression of cytokines.