Variation of IL-7 and IL-15 plasma levels as well as IL-7 receptor (CD127) expression after Ab-mediated CD4⁺ and CD8⁺ lymphocyte depletion in nonhuman primates. (A-B) Plasmas isolated from healthy SIV-uninfected SMs and RMs were tested for levels of IL-7 (black line) and IL-15 (red line). Levels of these cytokines are expressed as percentage variation from baseline (mean ± SD) in SMs (left graphs) and RMs (right graphs) after Ab-mediated CD4⁺ (A) and CD8⁺ (B) lymphocyte depletion. (C) Correlation between change over time (Δ; ie, percentage variation compared with baseline) of plasma IL-7 and those of proliferating CD4⁺Ki67⁺ T cells. (D) Levels of CD4⁺CD127⁺ T cells (expressed as percentage variation from baseline) in SMs (black line) and RMs (red line) after Ab-mediated CD4⁺ lymphocyte depletion. The dotted lines in the graphs indicate the timing of anti-CD4 monoclonal antibody administrations.