(A) Purified CD8⁺ T cells were plated with or without 5 ng/mL human IL-7. Ratio of cells surviving to number of cells plated is displayed over time. Data are combined from 3 experiments. Analysis by 2-way ANOVA yielded a significant interaction effect, indicating that the slopes of the two lines differ significantly. (B–D) Purified CD8⁺ T cells from WT and MD4 mice were dye-labeled, mixed in equal numbers, and cotransferred into WT or MD4 mice. (B) Experimental schematic. (C) Ratio of transferred cells in blood 2 hours after transfer, and in spleens 7 days later. (D) CD127 and CD122 gMFI was analyzed on transferred cells and endogenous naive CD8⁺ T cells on day 7. (E) Purified CD8⁺ T cells from WT or MD4 mice were stimulated with plate-bound anti-CD3. Representative proliferation dye dilution (top) and proliferation index (bottom). (F–I) Purified OT1 T cells from WT or MD4 mice were dye-labeled, mixed in equal numbers, and transferred into sublethally irradiated recipients. Spleens were analyzed 10 days later. (F) Experimental schematic. (G) Representative proliferation dye dilution as percentage of maximum (left) or as total counts (right). (H and I) Proliferation (H) and expansion (I) indices. (J–M) Purified OT1 T cells from WT and MD4 mice were mixed in equal numbers and transferred to recipient mice, which then received subunit vaccination. (J) Experimental schematic. (K) Ratio of transferred OT1 T cells at day 3. (L) Representative EdU incorporation plots. (M) Quantification of EdU incorporation. Data shown are means ± SEM, representative of ≥2 experiments. Significance was defined by 2-way ANOVA with Holm-Šidák multiple-comparison test; *P < 0.05, **P < 0.01, ***P < 0.001.