R-sIL-7 therapy eliminates PEG-IFN-α–induced lymphopenia. (A) Evolution of CD3⁺ (left panels), CD4⁺ (middle panels), and CD8⁺ (right panels) T-cell counts in IFN-α and IFN-α plus IL-7–treated macaques. Macaques 1 and 2 (top panels; white and gray bars, respectively) were treated with weekly injections of PEG-IFN-α (35 μg/kg). Macaques 3, 4, and 5 (bottom panels; white, gray, and black bars, respectively) received weekly injections of PEG-IFN-α (35 μg/kg) and 4 injections of R-sIL-7gly (80 μg/kg) once every 3 weeks for a total of 10 weeks. (B) Evolution of CD4⁺ naive (top panels) and central memory (TCM; bottom panels) T-cell counts in macaques 1 and 2 (left panels; white and gray bars, respectively) as well as in macaques 3, 4, and 5 (right panels; white, gray, and black bars, respectively). (C) Evolution of CD8⁺ naive (top panels) and central memory (TCM; bottom panels) T-cell counts in macaques 1 and 2 (left panels; white and gray bars, respectively) as well as in macaques 3, 4, and 5 (right panels; white, gray and black bars, respectively).