£²£²²óÆüËܸ¦µæÈéÉæ²Ê³Ø²ñÁí²ñ¡¦¾¶Ï¿



-1- Immunology(1) 9/4 Room-A
SUPPRESSIVE EFFECT OF ULTRAVIOLET (UVB AND PUVA) RADIATION ON SUPERANTIGEN FROM STAPHYLOCOCCUS AUREUS.
Miki Mishima, Hirohiko Akamatsu, Takeshi Horio.
Department of Dermatology,Kansai Medical University, Osaka, Japan.
It is generally accepted that a large number of S. aureus are seen on the moist skin lesion of atopic dermatitis. Reduction of bacteria from skin lesions by antibiotics has been reported to be effective on atopic dermatitis. S. aureus produces superantigens which can activate T cells and possibly enhance inflammation. For the treatment of severe cases of atopic dermatitis, photo (chemo)therapy is successfully used in our clinic. We have previously reported that photo(chemo)therapy had bacteriostatic effect on S. aureus . Now we examined the effect of photo(chemo)therapy on superantigens produced from S. aureus. We isolated S. aureus from 5 atopic dermatitis patients. S. aureus was irradiated with UVB(0,5,10mJ/cm2) and PUVA(0.001 % psoralen plus 0,5,10mJ/cm2) and incubated 4 hour with 100 strokes per minute. After incubation superantigens were measured from the supernatant using ELISA kit. The amount of superantigens was decreased in ultraviolet dose dependent manner. In conclusion photo(chemo)therapy is thought to be effctive to atopic dermatitis by supressing production of superantigen.
-2- Immunology(1) 9/4 Room-A
T-CELL PROLIFERATION TO SUPERANTIGEN-RELEASING STAPHYLOCOCCUS AUREUS BY MHC CLASS II-BEARING KERATINOCYTES UNDER PROTECTION FROM BACTERIAL CYTOLYSIN.
Yoshiki Tokura, Fukumi Furukawa, Hisashi Wakita, Hiroaki Yagi, Naohiro Seo, Masahiro Takigawa.
Department of Dermatology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Skin-colonization with S. aureus is one of the factors for exacerbation of skin disorders. This effect is mediated by activation of lesional T cells with released superantigens. Although T cells are effectively stimulated with superantigens in the presence of epidermal accessory cells, it remains to be elucidated whether cutaneous colonization with S. aureus can activate T cells. We examined how T cells are stimulated in the presence of keratinocytes by mitomycin C (MMC)-treated S. aureus. PBMC proliferated well to MMC-treated S. aureus and bacterial supernatants. When purified T cells were cultured with MMC-treated S. aureus or supernatant in the presence of INF-g-pretreated keratinocytes, the supernatant, but not MMC-treated S. aureus, stimulated T cells. MMC-treated S. aureus and a-toxin had cytotoxic effects on keratinocytes. This suggests that no response of T cells to S. aureus plus keratinocytes is due to damage of superantigen-presenting function of keratinocytes by cytolysin. Given that S. aureus-colonized skin provides circumstances in which viable keratinocytes are exposed to excreted superantigens but not to active cytolysin(s), T cells may be effectively stimulated by S. aureus.
-3- Immunology(1) 9/4 Room-A
RANTES, GRO-a, TNF-a RELEASE FROM in vitro EPDERMIS MODELS FOLLOWING TREATMENT OF Staphylococcal enterotoxin A.
Hidekazu Yamada, Tatuo Yudate, Masaharu Matukura, Tatashi Tezuka.
Department of Dermatology, Kinki University School of Medicine, Osaka, Japan.
Human skin equivalent cultures are currently being investigated as in vitro models to predict the cytokine expression. The object of the research presented here is to evaluate the production of panel of immunomodulatory cytokines under the Staphylococcus infection and to determine the modulation of these cytokines following exposure to Staphylococcal enterotoxin in the MatTek EpiDerm model. Epiderm cultures were topically treated with Staphilococcus aureus, SEA, SEA with several cytokine, assay medium, or no treatment for 24 hours. TNF-a, GRO-a, RANTES were measured by ELISA. Treatment with SEA produced increase of TNF-a, GRO-a but not RANTES. SEA With IFN-g produced RANTES. These studies demonstrate S.aureus modulate cytokine production from keratinocyte.
-4- Immunology(1) 9/4 Room-A
ANALYSIS OF THE SITE FOR T CELL MITOGENIC ACTIVITY IN THE AMINO-TERMINAL REGION OF SUPERANTIGEN STREPTOCOCCAL PYROGENIC EXOTOXIN C.
Jun-ichi Yamaoka1, Eijiro Nakamura2, Nagahiro Minato2, Sadao Imamura1.
1Department of Dermatology, 2Department of Immunology and Cell Biology, Faculty of Medicine, Kyoto University, Kyoto, Japan.
Superantigen streptococcal pyrogenic exotoxin C (SPEC) which has biological properties such as erythrogenic effect and pyrogenicity has been speculated to cause or aggravate infectious inflammation, psoriasis and atopic dermatitis. In this study, we investigated the essential amino acid residues for T cell mitogenic activity in the amino-terminal region of SPEC. We constructed 14 mutant SPECs by site-directed mutagenesis and purified these toxins by Glutathione S-transferase gene fusion system. Of these mutant toxins, Y15I in which tyrosine at the position 15 from the N terminus of SPEC was replaced by isoleucine showed 1000-fold reduction compared with wild-type SPEC in incorporation of [3H]thymidine by human peripheral blood mononuclear cells. This result suggests the importance of tyrosine at the position 15 for T cell mitogenic activity of SPEC.
-5- Immunology(1) 9/4 Room-A
CYTOKINE SYNTHESIS BY PERIPHERAL BLOOD MONONUCLEAR CELLS OF BEH¹¦T'S DISEASE FoLLOWING A STIMULATION BY STREPTOCOCCAL ANTIGENS.
Hideki Nakajima, Mitsunori Ikeda, Yasuo Yamamoto, Hajime Kodama.
Department of Dermatology, Kochi Medical School, Nankoku, Kochi, Japan.
Streptococci in oral cavity have been postulated to play etiological roles in Beh¹Æt's disease. Our hypothesis is that streptococcal antigens (SA) stimulate the production of cytokines by which neutrophils infiltrate and survive in the lesional skin. In this study, peripheral blood mononuclear cells obtained from Beh¹Æt's disease patients were stimulated by soluble membrane fractions of S. sanguis, S. salivarius and S. pyogenes. Concentration of granulocyte-colony stimulating factor (G-CSF), interleukin (IL)-2 and IL-8 in the medium was assayed by ELISA. G-CSF synthesis was up-regulated after a stimulation with SAŽÊin Beh¹Æt's disease patients much more than in controls. Among the SA tested, S. sanguis showed the most potent effect. IL-2 production was not influenced by a stimulation with SA in both Beh¹Æt's disease patients and controls. IL-8 synthesis by mononuclear cells from Beh¹Æt's disease patients were extremely high despite of an SA stimulation. These findings indicate that SA up-regulate the synthesis of G-CSF by monocytes and play a role in the development of the clinical symptoms in Beh¹Æt's disease. Mononuclear cells of Beh¹Æt's disease potentially synthesize IL-8 that induces neutrophilic cell infiltration.
-6- Immunology(1) 9/4 Room-A
Paracrine Growth regulation of sezary cells by IL-2 and IL-7.
Shigetoshi Sano, Mari Higashiyama, Satoshi Itami, Kunihiko Yoshikawa.
Department of Dermatology, Osaka University Medical School, Osaka Japan.