Figure 1. Subset distribution of circulating T cells in renal transplant recipients after treatment with tacrolimus, MMF and steroids over time.

(A) Representative dot plots for a renal transplant recipient showing CD3⁺CD4⁺ and CD3⁺CD8⁺ T cells within the CD45⁺ lymphocyte population. Circulating CD4⁺ and CD8⁺ T cells can be characterized as naive (T_N; CD27⁺CD45RO⁻), central memory (T_CM; CD27⁺CD45RO⁺), effector memory (T_EM; CD27⁻CD45RO⁺) and highly differentiated memory (T_EMRA; CD27⁺CD45RO⁻) cells. Furthermore, CD4⁺ T cells can be characterized as regulatory T cells (T_REGS; CD25^hiFOXP3⁺). (B) Shown are the absolute numbers of CD4⁺ T cells and the percentages of T_N, T_CM and T_EM within the CD4⁺ T-cell population for 14 triple immunosuppression-treated patients before transplantation (t = 0) and at 3, 6, 12 and 24 months after transplantation (n = 10 at 24 m). (C) As described under B, for CD8⁺ T cells. (D) The ratio between the percentage of CD4⁺ T_CM or T_EM and the percentage of T_REGS. (E) Longitudinal analysis of the percentages of CXCR3⁺, CCR4⁺, and CCR6⁺ cells within the CD4⁺ T-cell population of 14 triple immunosuppression-treated patients (n = 10 at 24 m). Results are shown as box plots displaying the median, 25^th and 75^th percentiles as the box, and the 5^th and 95^th percentiles as whiskers. Significant differences are indicated compared to pre-transplant levels: *P<0.05, **P<0.01.