R-sIL-7gly stimulates thymic function in PEG-IFN-α–treated macaques. (A) sjTREC blood concentration measured in macaques 1 and 2 treated with weekly injections of PEG-IFN-α (35 μg/kg) for 10 weeks (left panels; white circles and squares, respectively) as well as in macaques 3, 4, and 5 (right panels; gray diamonds, triangles, and squares, respectively) that 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) CD31^Hi CD4⁺ (RTE CD4⁺; top panels) and CD31^Low (bottom panels) T-cell counts measured in macaques 1 and 2 (left panels; white and gray bars, respectively) and in macaques 3, 4, and 5 (right panels; white, gray, and black bars, respectively). Right y-axes correspond to macaques 2 (top and bottom left panels) and 5 (bottom right panel).