Differentiation of CMV-specific and total CD8⁺ T cells in asymptomatic and symptomatic patients.

(A-D) Differentiation of CD8⁺ T cells in one asymptomatic individual representative of all patients (patient 2). Time defined as days after first positive PCR (day 0), all plots gated on CD8⁺ T cells. CMV-specific CD8⁺ T-cell frequencies (percent of total CD8⁺ T cells): day 31, 4.96%; day 59, 4.58%; day 76, 3.30%; day 279, 1.29%. CMV-specific CD8⁺ T cells as defined by specific tetramer staining are plotted in black, total CD8⁺ T cells are plotted in red. Quadrant percentages are depicted in black for CMV-specific CD8⁺ T cells and in red for total CD8⁺ T cells. (A) x-axis log fluorescence CD27-FITC, y-axis log fluorescence CD28-PE; (B) x-axis log fluorescence CD27-PE, y-axis log fluorescence CD45RA-FITC; (C) x-axis log fluorescence CCR7-PE, y-axis log fluorescence CD45RA-FITC; (D) x-axis log fluorescence CD45R0-PE, y-axis log fluorescence CD45RA-FITC. (E) Correlation of viral load and percentage of CD28⁻CD27⁻ cells of CMV-specific CD8⁺ T cells, during all time points of infection, undetectable viral load was set at the cutoff point of the quantitative PCR at 80 copies/mL.