Fig. 1

Exosomes from patients with MS can selectively decrease the frequency of Treg cells a Representative size distribution of purified exosomes. Using a NanoSight LM10 nanoparticle analysis system, the size was analysed three times for each sample. Red error bars indicate the standard error of the mean. b Western blot analysis for CD9, CD63 and Cytochrome c proteins. The PBMC and exosome samples were collected from HC. Each lane was loaded with 3 μg of protein for blotting. c Dot plot and histogram of flow cytometry data. T cells were prepared from the peripheral blood of a healthy volunteer. They were cultured with PBS as a control or with exosomes derived from HC (HC-exosome) or patients with MS (MS-exosome) under stimulation with anti-CD3 and anti-CD28 mAbs for 48 h. IFN-γ⁻IL-17A⁻CD4⁺ T cells were defined as shown in the left panel, and then the expression of Foxp3 was evaluated as shown in the right panel. d The frequencies of inflammatory and regulatory T cells among CD4⁺ T cells after the culture described above. Among Foxp3⁺CD4⁺ T cells, IFN-γ⁻IL-17A⁻Foxp3⁺CD4⁺ T cells are known to represent most effective Treg population^{8, 22, 23}, whereas Foxp3⁺CD4⁺ T cells secreting IFN-γ or IL-17A are supposed to be dysfunctional in the suppressive activity^{8, 22,23,24,25}. Data are representative of two independent experiments. A one-way ANOVA with Bonferroni’s comparison test was used for statistical analysis. Error bars represent the mean ± s.d. *p < 0.05, **p < 0.01. s.d. standard deviation, n.s. not significant, ANOVA analysis of variance, Cyt c cytochrome c, PBMC peripheral blood mononuclear cell, EV extracellular vesicle, PBS phosphate-buffered saline