T cells transduced with affinity-matured TCR down-regulate TCR faster and to a greater level than T cells transduced with Tax-TCR. (A-B) Jurkat cells and (C) primary T cells transduced with the Tax TCR and the affinity-matured TCR were cocultured with T2 stimulator cells loaded with saturating concentration of Tax peptide (100μM) for the stated time periods. Jurkat cells were stained with anti-Vβ13 antibodies and primary T cells were stained with anti-CD8 antibodies and tetramer (the axis of the FACS plots range from 10¹ to 10⁵). Shown is a representative of 4 independent Jurkat experiments showing similar results. Primary T cells were gated on the CD8⁺ T-cell population; the percentage of tetramer-positive CD8⁺ T cells at time 0 was 63%, 68%, 68%, and 55% for the Tax-TCR, M1-TCR, M2-TCR, and M3-TCR, respectively. Shown is the relative loss of tetramer-positive T cells after peptide stimulation. This is a representative of 3 independent experiments showing similar results.