Figure 4. Ag-activated T^CXCR4 adopt a less differentiated memory phenotype.

Equal numbers of OT-I T^CXCR4 and T^Control were coinjected into Rag1ko mice, which then underwent prime-boost vaccination with relevant SIINFEKL peptide plus IFA on days 1 and 29. Tissues were harvested on day 36 (n = 9); data are pooled from 4 independent experiments. (A and B) Representative flow cytometric histograms (A) and summary data (B) for expression of surface IL-15Rβ (CD122), intracellular Bcl2, EdU incorporation, and caspase-3 activity in T^Control (blue) versus T^CXCR4 (red) on day 36 in cells isolated from the BM. Statistical significance was tested using Wilcoxon’s ranked-sum test (2-tailed). *P ≤ 0.05, **P ≤ 0.01. (C and D) Representative flow cytometric histograms (C) and summary data (mean ± SD) (D) for CD62L and Bcl2 staining in BM T^CXCR4 gated according to GFP reporter expression (gates 1–4).Numbers shown as insets of the flow cytometric histograms relate to CD62L median fluorescence index (MFI) and proportion of Bcl2⁺ cells in the gated subset. Statistical significance was tested using the Mann-Whitney test (2-tailed). *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001. (E and F) Representative flow cytometric contour plots (E) and summary data (F) for frequency of splenic T^Control (blue) and T^CXCR4 (red) with short-lived effector cell (SLEC) (KLRG-1^hiCD127^lo), MPEC (KLRG-1^loCD127^hi), and exhausted (PD-1^hiEomes^hi) phenotypes on day 36 (n = 5). Statistical significance was tested using Wilcoxon’s ranked-sum test (2-tailed). *P ≤ 0.05.