Abstract: Bao Huaye, Zhou Miaoni, Xu Aie. Hangzhou Clinical College Affiliated to Anhui Medical University, Department of Dermatology, Third People′s Hospital of Hangzhou, Hangzhou 310009, China Corresponding author: Xu Aie, Email: xuaiehz@msn.com 【Abstract】 Objective To evaluate the effect of human dermal mesenchymal stem cells （DMSCs） on the expression and secretion of interleukin （IL）-13 by perilesional CD8+ T lymphocytes from patients with vitiligo. Methods Tissue specimens were obtained from the perilesional region of six patients with active vitiligo, and CD8+ T lymphocytes were isolated from both the tissue specimens and peripheral blood of these patients. DMSCs and melanocytes were obtained from the foreskin tissue of healthy males. The 3-（4,5-dimethylthiazol-2-yl）-5-（3-carboxymethoxyphenyl）-2-（4-sulfophenyl）-2H-tetrazolium, inner salt （MTS） assay was performed to estimate the effect of different concentrations of recombinant IL-13 on the proliferation of melanocytes, reverse transcripition-PCR and Western blotting to detect the mRNA and protein expressions of IL-13 in perilesional and peripheral blood CD8+ T lymphocytes respectively, real-time quantitative reverse transcription （RT）-PCR and enzyme-linked immunosorbent assay （ELISA） to detect the IL-13 mRNA expression in, and IL-13 protein expression in the culture supernatant of, CD8+ T lymphocytes before and after coculture with DMSCs, respectively. Statistical analysis was done by t test. Results No obvious changes were observed in the proliferation of melanocytes treated with different concentrations （10, 50, 100, 250, 500 μg/L） of recombinant IL-13 for various durations （24, 48, 72 and 96 hours） compared with untreated melanocytes （all P > 0.05）. Both perilesional and peripheral blood CD8+ T lymphocytes expressed IL-13, and the expression was stronger in perilesional than in peripheral blood CD8+ T lymphocytes. A significant decrease was noted in IL-13 mRNA expression （0.100 0 ± 0.002 4 vs. 0.383 2 ± 0.018 7, P < 0.05） and protein level in the culture supernatant （（1 509.62 ± 48.44） ng/L vs. （5 507.98 ± 34.11） ng/L, P < 0.05） of CD8+ T lymphocytes cocultured with DMSCs compared with monocultured CD8+ T lymphocytes. Conclusions There is a strong expression of IL-13 by perilesional CD8+ T lymphocytes in patients with vitiligo, which may be inhibited by DMSCs and serve as a target for the treatment of vitiligo.

Key words: Vitiligo, CD8-positive T-lymphocytes, Mesenchymal stem cells, Interleukin-13