Fig. 2. PD-1 pathway blockade moderately improves antigen-independent persistence and IL-7 signaling in TEX.
(A) Number of DbGP33+ donor CD8 Tcells per million peripheral blood mononuclear cells (PBMCs) at day 27 (compared to day 1) after transfer and (B) number recovered from the spleen. (C) Histograms of CD127 and CD122 expression on TEX P14 cells (day 35 after clone 13) compared to TMEM P14 cells or bulk CD44lo CD62L+ TN cells [day 167 after LCMV strain Armstrong (Arm)]. Values indicate average geometric mean fluorescence intensity (MFI) and SEM. (D) Contour plots of PD-1 versus CD127 from mice in (C). (E) Quantification of (D). Data in (A) to (E) are representative of at least two independent experiments with at least four mice per group. (F) Quantification of phospho-STAT5 induction by P14 cells at day 39 after infection after ex vivo stimulation with IL-7 or IL-15 for 30 min. Values indicate fold change over unstimulated controls. (G) Frequency (of CD8+, left) and number (right) of P14 cells in the spleen after 2 weeks of treatment. (H) Plots (left) and quantification (right) of IFNγ+ TNFα+ P14 cells from (G) after ex vivo peptide stimulation. Data in (F) to (H) are combined from two independent experiments with at least four mice per group. Asterisks indicate statistical significance (*P < 0.05, **P < 0.01, and ***P < 0.001) determined as described in the supplementary methods. Blue asterisks indicate analysis of variance (ANOVA) P values; black asterisks indicate post-test P values.