Abstract: OUYANG Jie, WU Ji-long, ZHOU Miao-ni, FU Li-fang, XU Ai-e. Department of Dermatology, Third People′s Hospital of Hangzhou, Hangzhou 310009, China Corresponding author: XU Ai-e, Email: xuaiehz@msn.com 【Abstract】 Objective To evaluate the protective effects of tea polyphenols against the destruction of melanocytes by CD8+ T cells from vitiligo patients. Methods Skin tissue was resected from the margin of vitiligo lesions followed by the isolation and culture of CD8+ T lymphocytes, and from the normal skin of vitiligo patients followed by the isolation and culture of melanocytes. Flow cytometry was carried out to evaluate the purity of CD8+ T cells. The melanocytes were cocultured with the CD8+ T cells at different ratios followed by the evaluation of killing effect of CD8+ T cells. Various concentrations （200 and 400 μg/ml） of tea polyphenols were added into the co-culture system of CD8+ T cells and melanocytes at a ratio of 5 ∶ 1 followed by an additional culture of 48 hours. Then, flow cytometry was performed to detect the apoptosis in melanocytes in the coculture system. Results CD8+ T lymphocytes were successfully obtained from the marginal area of vitiligo lesions with a purity of more than 90%, which highly expressed the antigens CD137 and CD69. The coculture with CD8+ T cells markedly accelerated the apoptosis in melanocytes, while the accelerative effect was inhibited by tea polyphenols of 200 and 400 μg/ml. Conclusions The CD8+ T cells infiltrating the edge of vitiligo lesions display a potential destructive effect on autologous melanocytes from vitiligo patients, and tea polyphenols have a protective effect against the destruction of melanocytes by CD8+ T cells. 【Key words】 Vitiligo; T-lymphocytes, cytotoxic; Melanocytes; Tea polyphenols

Key words: Tea polyphenols