Fig. 1.

Double-positive (DP) T cell frequency in the peripheral blood of multiple sclerosis (MS) patients and controls. (a) The percentage of CD4⁺CD8⁺ DP T cells within the peripheral blood CD45⁺CD3⁺ T cell population was assessed by flow cytometry in treatment-naive MS patients with relapsing–remitting disease (RRMS, n = 30) and healthy donors (control, n = 41). (b) Exemplary dot plot of DP T cell staining in two different donors demonstrating the high interindividual variation concerning the proportions of CD4^hiCD8^lo and CD4^loCD8^hi cells within the DP T cell population. (c) Percentages of CD4^hiCD8^lo DP T cells within the peripheral blood CD3⁺ T cell population as assessed by flow cytometry. (d) Percentage of CD4^loCD8^hi DP T cells within the peripheral blood CD3⁺ T cell population as assessed by flow cytometry.