Differential expression of the transcription factors T-bet and Eomes in CMV-specific T cells. PBMCs from CMV-seropositive donors were incubated for 5 hours with cognate peptide epitopes, labeled with anti-CD8, and then assessed for intracellular expression of IFN-γ, T-bet, and Eomes. (A) Representative analysis of T-bet and Eomes expression in ELR/K-, VTE-, NLV-, and IPS-specific IFN-γ–producing cells is shown as an overlay of total CD8+ T cells. (B) Data represent the mean ± SEM of the proportion of CMV-specific T-cell populations displaying a T-betloEomeshi, T-betintEomeshi, or a T-bethi phenotype. Data represent analysis from at least 6 donors for each peptide tested. (C) Data represent the mean ± SEM of the ratio of mean fluorescent intensity of T-bet: mean fluorescent intensity of Eomes in different CMV-specific T-cell populations.