Fig. 1

a Gating strategy for determination of Treg frequency (i) = initial population, (ii) = singlets, (iii) = live cells, (iv) = lymphocytes, (v) = CD45hi cells, (vi) = CD3+ cells (T cells), (vii) = CD4+ T cells vs. CD8+ T cells, (viii) = CD4+ CD25+ FoxP3+ cells (quadrant in red) designated Tregs. b Flow cytometric analysis of splenic Treg frequencies in a mouse model of brain ischaemia. 15–17-week-old male, C57BL/6 mice underwent permanent middle cerebral artery occlusion (pMCAO). At 2, 24, and 48 h post-ischaemia, mice received either saline or fingolimod (0.5 mg/kg or 1 mg/kg) by intraperitoneal injection (n = 16 mice per group). Age-matched mice who had not undergone pMCAO acted as immunological controls (n = 8). At 7 days post-ischaemia, flow cytometry was used to determine the frequency of splenic Treg cells. All gates were determined by both negative cells and fluorescence minus one controls