Down-regulation of TCR after stimulation with HLA A24–positive fibroblast cells infected with recombinant vaccinia viruses expressing each of the EBV genes.

Before staining with Tet-11, Tet-21, Tet-24, Tet-43, or Tet-44, aliquots of EBV-specific CD8⁺ T cells were incubated with HLA A24–positive fibroblast cells infected with recombinant vaccinia virus expressing LMP2 (vLMP2), vBRLF1, vBMLF1, vEBNA3A, or vEBNA3B, respectively (top row). For control stimulation, aliquots of EBV-specific CD8⁺ T cells were incubated with HLA A24–positive fibroblast cells infected with vEBNA3A, vBMLF1, vBRLF1, vEBNA3B, or vEBNA3A, respectively (bottom row). After a 16-hour incubation, the cells were stained with PE-conjugated HLA A*2402 tetramers and TRI-COLOR–labeled anti-CD8 mAb and analyzed by FACSCalibur. Numbers in the top right quadrants represent the percentages of tetramer-positive cells in the total CD8^high cells.