Figure 1. T_Mem cells augment naive cell phenotypic maturation during priming.

(A) Experimental design and representative FACS plot showing the generation and isolation of vaccine-induced pmel-1 Ly5.1⁺CD8⁺ T_CM (CD44⁺CD62L⁺) and T_EM (CD44⁺CD62L^–) cell subsets by adoptive transfer of pmel-1 cells (10⁶) into Ly5.2⁺ WT hosts followed by rVV-gp100 vaccination (2 × 10⁷ pfu). (B) Representative FACS plots and (C) summary bar graphs demonstrating the distribution of Thy1.1⁺ T_N-derived T_SCM (CD44^loCD62L⁺Sca1⁺CD122⁺) and T_EM cell subsets 6 days following ex vivo expansion alone or in the presence of a 1:1 mixture with Ly5.2⁺ T_CM or T_EM cells using CD3/CD28-specific antibodies and IL-2. (D) Representative FACS plots and (E) summary graph demonstrating the distribution of Thy1.1⁺ T_N-derived subsets 6 days following ex vivo expansion alone or in the presence of titrated ratios with Ly5.1⁺ bulk (CD44⁺) T_Mem cells using CD3/CD28-specific antibodies and IL-2. Results in A–E are shown after gating on live⁺CD8⁺Thy1.1⁺ lymphocytes and are representative of 2 independently performed experiments. Results in C and E are presented as mean ± SEM with n = 3 per condition. Statistical comparisons performed using an unpaired 2-tailed Student’s t test corrected for multiple comparisons by a Bonferroni adjustment. ***P < 0.001.