Effect of 308 nm laser irradiation on Treg cells and Th17 cells in guinea pigs modelling vitiligo

Objective To assess the efficacy of 308 nm excimer laser irradiation for the treatment of guinea pig model of vitiligo and its immunoregulatory effect on Treg cell and Th17 cell. Methods Vitiligo was induced in guinea pigs by hydroquinone bleaching, and they were randomly divided into an experimental group and a control group. There was also a normal control group. The experimental group was treated with a 308 nm excimer laser at the nidus of vitiligo; the two control groups were given no intervention. After 8 weeks of treatment, leukasmus of the different groups were compared. The mRNA expression of Foxp3 and IL-17 were measured by real-time fluorescence quantitative (RTFQ-PCR) and the expression of Foxp3 and IL-17 in the lesions were measured by immunohistochemistry staining. Results The effectiveness rate was 100% in the experiment group. The results of RTFQ-PCR showed that the mRNA expression of Foxp3 in the experimental group and the vitiligo control group was significantly higher than the healthy control group (all P<0.05), being 0.33±0.03 and 0.02±0.07 respectively, as was the mRNA expression of IL-17, being 0.21±0.05 and 0.94±0.06 accordingly; and the mRNA expression of IL-17 in the experimental group was significantly lower than the vitiligo control group(P<0.05). The immunohistochemical staining showed that Foxp3 and IL-17 protein was scattered in the lesions of the experimental group, while they were crowded in those of the vitiligo control group. Conclusion Laser irradiation might contribute to a therapeutic effect on vitiligo through modulating the balance of Treg and Th17 cells, at least in guinea pigs. Key words: 308 nm excimer laser; Vitiligo; Regulatory T cell; Th17 cell