Figure 5. Melatonin increased FoxP3 and IL-10 expression and enhanced the suppressive function of Tregs ex vivo. (A) Frequency of CD4+CD25hiFoxP3+ Tregs after melatonin stimulation (HC, n=14; MG, n=14). (B) Frequency of CD4+CD25hiCD127low Tregs (HC, n=14; MG, n=14). (C) Relative expression of FoxP3 in PBMCs from MG patients and HCs (HC, n=14; MG, n=38). The results are representative of three independent experiments. Relative expression of FoxP3 after melatonin treatment in MG patients (D) and HCs (E). (F) FoxP3 expression in CD4+ T cells of MG patients and HCs after melatonin treatment (HC, n=15; MG, n=23). (G) IL-10 expression in CD4+ T cells of MG patients and HCs after melatonin treatment (HC, n=10; MG, n=10). CD4+CD25hiCD127low Tregs and CD4+CD25- Tresps were sorted. Tresps were labeled with CFSE and cocultured with Tregs with or without melatonin in the presence of PHA. Four days later, the percentage of Tresps was determined based on CFSE dilution and FCM. (H) CD4+ T cells enriched from HCs. (I) CD4+ T cells enriched from MG patients (HC, n=10; MG, n=10). The data represent the mean ± SD. * P ≤ 0.05, ** P ≤ 0.01, *** P ≤ 0.001 and ns=no significance.