Fig. 3 |. Iterative boosting induces progressive changes in gene and protein expression and acquisition of exhaustion markers.

a, RNA-seq was carried out on naive and N-specific memory CD8⁺ T cells that had experienced progressive boosts. Shown is a heatmap of the genes that were previously reported⁴² to be uniquely expressed by exhausted CD8⁺ T cells. b,c, The phenotype of naive and various generations of H-2K^b/N_52–59-specific memory cells isolated from blood was assessed by flow cytometry. All samples were run on the same day from staggered cohorts. The right column in c indicates days after last boost. a, n = 3 per group. b,c, Representative of n = 3 (7°), n = 4 (3°, 12°, 19° and 31°) or n = 9 (51° and naive), from at least two independent experiments with similar results. For flow cytometry gating strategies, see Supplementary Fig. 3.