Figure 2. Phenotype and proliferation of CD57⁺ and/or KLRG1⁺ CMV-specific CD8⁺ T cells from primary into chronic CMV infection.

(A) Representative flow cytometry plots from the Acute CMV showing phenotype and CMV pp65-specific proliferation in response to pp65 pooled peptides (lower panels) or medium alone (negative control) (upper panels), KLRG1⁺ (middle panels) and T-bet⁺ (right panels). (B) Representative flow plot from (A) showing KLRG1^+/− and CD57^+/− phenotypes in CD8⁺CFSE^lo subset (right panel). (C) Cumulative data showing CMV pp65-specific proliferation at 6 days for CD8⁺ T cells with respect to CD57⁺ (orange bars), CD57⁻ (green bars) of CFSE^lo events (n=7). Bars represent median values of CFSE^lo events for CD57⁺KLRG1⁻, CD57⁺KLRG1⁺, CD57⁻KLRG1⁺ and CD57⁻KLRG1⁻ respectively. Statistical analysis performed using Mann-Whitney U test with a two-sided and p value of less than 0.05 considered statistically significant. (D) Graphs showing frequencies of CMV-dextramer CD8⁺ T cells, and KLRG1^+/− CD57^+/− subsets in three patients during Acute-CMV, Contraction phase, and Chronic CMV infection. Samples for the contraction phase were obtained 1–2 months following clearance of acute viremia and Chronic CMV at least a year post-Acute CMV. (E) Representative flow cytometry plots of CMV dextramer proliferation in response to cognate peptide re-stimulation or medium measured at 6 days using CFSE dilution. Shown are responses during Acute-CMV and Chronic CMV and phenotypic markers CD57⁺ (upper left), CD27⁺ (upper right), KLRG1⁺ (lower left) and T-bet⁺ (lower right) plots. (F) Cumulative data from (E) showing respective phenotypes of CFSE^lo events in dextramer⁺ cells. during Acute-CMV (orange bars) and Chronic CMV (green bars). Bars represent median values of CFSE^lo frequencies. Statistical analysis performed using Mann-Whitney U test with a two-sided and p value of less than 0.05 considered statistically significant. NS=non-significant.