High expression of IL-7Rα does not induce up-regulation of Bcl-2 on Melan-A–specific CD8⁺ T cells at the effector phase, but it does it at the contraction and memory phases. (A) Melan-A–specific effector CD8⁺ T cells expressing low (■) and high () levels of CD127 were analyzed for intracellular Bcl-2 expression upon recombinant lentivector and peptide immunizations. Error bars represent SD (n = 5 or 6). (B) Kinetics of Bcl-2 expression ex vivo in CD127^lo and CD127^hi Tet⁺CD8⁺ T cells, and in Tet⁻CD8⁺ T cells upon recombinant lentivector (top panels) and peptide (bottom panels) immunizations. The indicated effector, contraction, and memory phases are shown, respectively, at days 18, 35, and 60 after immunization with recombinant lentivectors, and at days 7, 19, and 40 after immunization with peptides. Round symbols represent individual mice; horizontal bars represent mean values. For Tet⁻CD8⁺ T cells, the mean value of 5 mice for each time point is shown. *P < .05.