IL-7-induced Ki-67 and Bcl-2 expression in circulating blood and homing target organs. Initiation of cell cycling, as evidenced by the expression of Ki-67 (A) and cell survival capacity, as evidenced by Bcl-2 expression (B), were quantified in circulating CD4⁺ and CD8⁺ T lymphocytes in R-sIL-7gly–injected rhesus macaques (no. 14424 and no. 14694, ■ and □) compared with noninjected control animals (no. 21045 and no. 26007, ● and ○) over a 14-day period after R-sIL-7gly injection. (C) Ki-67⁺ cells were identified in lymph nodes, in Peyer patches (ileum), in the lamina propria (ileum, colon, and rectum) and in the skin of animals killed at H0, H24, and D7 after R-sIL-7gly injection. Magnification: ×100. Ki-67⁺ T-cell quantifications, performed on 5 to 6 fields (0.09 mm²) randomly selected from 4 slides for each organ in macaques killed at H0, H24, and D7 after R-sIL-7gly injection are shown on the right. Statistical differences between H0 and either H24 or D7 are shown on top (Mann-Whitney test).