Representative analysis of Tax 11-19– and APL-specific CD8⁺ T cells in PBMCs from patient no. 31 on 3/5/97 by flow cytometry.

PBMCs were cocultured with APCs prepulsed with either Tax 11-19, APL, or no peptide (NP) for 6 hours in the presence of brefeldin A, a reagent to accumulate synthesized proteins in the Golgi apparatus. The culture cells were stained with anti-CD8 and anti–IFN-γ antibodies. The lymphocytes were segregated from the APCs by size on the forward and side scatter and IFN-γ⁺ cells were gated as shown. The number in the gate indicates the frequency of IFN-γ⁺ cells in CD8⁺ cell population. Tax is the cognate Tax 11-19 peptide and APL was designated as G4A (glycine at position 4 of Tax 11-19 was substituted by alanine).