FIG. 2.

IFN-γ production in response to mitogen or peptide-specific stimulation at week 36 postchallenge. Tetramer-positive cells are still able to respond to mitogen stimulation, although they demonstrate reduced ability to respond to specific peptide stimulation at week 36 postchallenge. PBMCs were either stimulated with autologous B-LCL in the presence of a control peptide (B-LCL), with PMA/ionomycin (PMA/Iono.), or with autologous B-LCL in the presence of CM9 peptide (CM9+BLCL). Between 100,000 and 150,000 events were acquired, gated on small lymphocytes. Numbers within graphs indicate the percentage of CD8⁺ cells in each quadrant. The background for the tetramer staining, using samples from Mamu-A*01-positive, uninfected or Mamu-A*01-negative, infected animals, was below 0.08%. The gate for IFN-γ staining was set using an isotype-stained control, so that less than 0.1% of CD8⁺ cells fell into the positive gate.