1998 Fiscal Year Final Research Report Summary
The relationship between DNA damage and immunosuppression by ultraviolet radiation
| Project/Area Number |
09670901
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Dermatology
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| Research Institution | Kansai Medical University |
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Principal Investigator |
HORIO Takeshi Kansai Medical University, Department of Dermatology, Professor, 医学部, 教授 (90026914)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMOTO Hiroyuki Kansai Medical University, Department of Dermatology, Associate Professor, 医学部, 助教授 (10142291)
HASHIMOTO Hiroko Kansai Medical University, Department of Dermatology, Research asociate, 医学部, 助手 (70257955)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Ultraviolet light / DNA damage / Immunosuppression / Xeroderma pigmentosum / NK cell |
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| Research Abstract |
The skin is an important immune organ which is composed of various immune competent cells. linmunologic functions of the skin are impaired by ultraviolet radiation(UVR), since the skin is an outermost organ.
First, we investigated the effect of mid-wave uv(UVR) on the induction of contact hypersensitivity. A variety of factors including total dose of UVR, devided UVR exposure, hapten concentration, and application area, modulated local and systemic UVR-induced inmiunosuppression.
The carcinogenesis of UVR has been well known. Gene-mutations based on the DNA-damage had been belived to be a main action of UVR in the carcinogenesis. Therefore, skin cancers easily develop in patients with xeroderma pigmentosum(XP) who have a defect in repair of DNA damage. Recently, however, it has been elucidated that UVR-induced suppression of tumor immunity is also involved. We demonstrated that XP modelambda mice, which were established by gene-targetting, easily develop not only skin cancers but also acute inflanunation and immunosuppression by UVR.This suggests that there may be close relationships among DNA-damage, UV-inflammation and immunosuppression. Furtheremore, UVR greatly suppressed the activity of natural killer cells. Most recently we found that XP mouse skin can produce a great amount of prostaglandins after irradiation of U-yR.We are now investigating if excess amounts of prostaglandins can explain the enhanced inflammation, immunosuppression and impaired NK cell activity.
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