Figure 1.

Frequency and absolute number of MAIT cells in peripheral blood. (A) Gating strategy to identify CD3⁺CD4⁻TCRγδ⁻CD161^highTRAV1-2⁺ MAIT cells in peripheral blood from MS patients (B,C) Blood MAIT cell frequency from 86 patients with MS (MS remission = 46, MS exacerbations = 25, PPMS = 15) were significantly lower than in 30 HCs, with greater decrease observed during MS exacerbations. (D) Frequency of CD25⁺ MAIT cells was significantly higher in all groups of MS patients compared to HCs, with greater increase during MS exacerbations. (E) CD69 was upregulated in MAIT cells from RRMS patients (both during remission and exacerbations) compared to HCs, but not in PPMS. (F,G) The frequency of CD69⁺ and CD25⁺ cells among MAIT cells was significantly higher than among non-MAIT cells in blood samples from 30 RRMS patients (in remission = 15, during exacerbation= 15), with greater increase observed during exacerbations. CD69 and CD25 expression in both MAIT cells and non-MAIT cells isolated from RRMS patients, was higher than in HC (n = 15) or PPMS patients (n = 15). Each symbol represents values from a single individual and the middle line represents the mean. Data are shown as mean ± SEM. Kruskal–Wallis test of one-way ANOVA and post-hoc data analysis applying Dunn's multiple comparison test were performed to analyze differences between groups (B–G). Wilcoxon matched-pairs signed rank test was also used for comparisons between MAIT vs. non-MAIT cell groups (F, G). ^*p < 0.05, ^**p < 0.01, ^***p < 0.001, ^****p < 0.0001.