Fig. 4

Effect of atorvastatin treatment on Tregs in the spleen and brain after TBI. a, b Representative dot plots showing the gating strategy of CD4 + CD25 + Foxp3 + Tregs from the peripheral spleen (a) and brain (b). Data are expressed as the Tregs in CD4+ T cells (%). c, d Quantitative analysis of the Tregs in the spleen and brain in the different groups. Mice in the TBI + saline group showed a decreased percentage of CD25 + Foxp3+ Tregs in spleen CD4+ T cells at 24 and 72 h (c); however, an increased percentage of Tregs in CD4+ T cells were present in the brain (d) at 72 h post-injury compared with mice in the sham groups. Atorvastatin treatment post-TBI increased the proportions of CD25 + Foxp3+ Tregs among CD4+ T cells significantly in both the spleen (c) and brain (at 72 h, d), compared with the TBI + saline group. Data are presented as the mean ± SD. *p < 0.05, **P < 0.01, and ***P < 0.001 versus sham group, ^### P < 0.001 versus TBI + saline group. n = 6/group. FSC-A = forward scatter channel area, SSC-A = side scatter channel area, FITC = fluorescein isothiocyanate, PE = phycoerythrin, and APC = allophycocyanin