Fig. 3

CD99 reduction on T cells in the CSF of male MS patients. A CD99 surface protein expression on subsets of cryoconserved peripheral blood mononuclear cells (PBMCs) from male (n = 30) and female (n = 30) MS patients as analyzed by flow cytometry. Cell subsets were identified as following: CD4⁺ and CD8⁺ memory (gated as living CD3⁺-CD4⁺/CD8⁺-CD45RA^– cells) and naïve (gated as living CD3⁺-CD4⁺/CD8⁺-CD45RA⁺ cells) T cells; pDCs (gated as living CD45⁺-Lineage(CD3, CD14, CD19, CD20, CD56)^–-HLA-DR⁺-CD11c^–-CD123⁺-CD304⁺ cells); cDCs (gated as living CD45⁺-Lineage(CD3, CD14, CD19, CD20, CD56)^–-HLA-DR⁺-CD11c⁺ cells); B cells (gated as living CD45⁺- CD19⁺-CD20⁺ cells); NK cells (gated as living CD45⁺- CD19^–-CD20^–-CD3^–-CD14^–-CD56⁺ cells) and monocytes (gated as living CD45⁺- CD19^–-CD20^–-CD3^–-CD14⁺ cells). B CD99 surface expression on freshly isolated T cells in peripheral blood and CSF of non-neuroinflammatory controls (n = 16) and MS patients (n = 33) as analyzed by flow cytometry. C Comparison of CD99 expression levels in the same set of non-inflammatory controls and MS patients. D Sex-specific analysis of CD99 surface expression in the same set of healthy individuals (n = 11 females, 5 males) and MS patients (n = 24 females, 9 males). Data are shown as mean ± SEM. Statistics: A two-way ANOVA with Tukey post-hoc; B Wilcoxon matched-pairs signed rank test; C Mann Whitney test; D two-way ANOVA with Sidak’s post-hoc; *P < 0.05; **P < 0.01; ***P < 0.001