Fig. 5

Analysis of T cell activation. (a) Percentage of activated CD4 and CD8 T cells was shown in PBMC from young (circles) and elderly (triangles) donors, control (white symbols) and TBI patients (black symbols). Activated T cells were identified as CD45R0+ CD45RA- in the gate CD3+ CD4+ for CD4 or CD3+ CD4- for CD8. (b) CD45RA and CD197/CCR7 markers were used to identified naïve (N), central memory (CM), effector memory (EM), and terminally differentiated effector memory (EMRA) T cells as follows. N: CD45RA+ CCR7+; CM: CD45RA- CCR7+; EM: CD45RA- CCR7-; EMRA: CD45RA+ CCR7-. The percentage of N, CM, EM, EMRA for both CD4 (c) and CD8 (d) T cells was shown in PBMC from young (circles) and elderly (triangles) donors, control (white symbols) and TBI patients (black symbols). The percentage of N, CM, EM, EMRA for CD4 (e) and CD8 (f) T cells was also analysed for injury severity, assessed as GCS. * p < 0.05; ** p < 0.01; *** p < 0.001 TBI vs. control aged-matched subjects. §§ p < 0.01; §§§ p < 0.001 young vs. elderly control subjects. # p < 0.05; ## p < 0.01; ### p < 0.001 young vs. elderly TBI patients