Functional antigen avidity test in Tax 11-19–specific CD8⁺ T cells in PBMCs from patient no. 31.

Samples were chosen at 3 time points, when the HTLV-1 proviral load was either high or low as shown in Figure 2A. The x-axis indicates HTLV-1 Tax 11-19 peptide concentration. (A) Frequencies of the HTLV-1 Tax 11-19–specific CD8⁺ T cells in CD8⁺ cell population, which were measured as in Figure 1. The y-axis indicates relative percentage as standardized by the frequency at 1000 nM in each sample. The frequencies at 1000 nM were 6.3% on 6/27/91, 18.5% on 3/5/97, and 10.6% on 3/10/99. (B) The MFI of IFN-γ–FITC produced by the HTLV-1 Tax 11-19–specific CD8⁺ T cells. (C) The MFI of CD8-PC5 in the Tax 11-19–specific CD8⁺ T cells.