Functional activity analysis of hTERT-transduced, HPV16 E711-20–specific CTL A9-TN. Lytic activity, determined in a chromium release assay using HLA-A2.1–positive JY target cells loaded with MP58-66 peptide (○) and E711-20 peptide (•) at the indicated E/T ratios, CD107a expression in response to E711-20 peptide–loaded JY cells and intracellular IFNγ staining in response to E711-20 peptide–loaded JY cells, respectively, are shown for (A) A9-TN during the first 12 months after hTERT transduction and (B) A9-TN beyond 12 months after hTERT transduction. CD107a and IFNγ staining are shown in combination with HLA-A2.1/E711-20 tetramer (T A2 E711-20) staining. No CD107a and IFNγ staining above background was observed in response to MP58-66 peptide–loaded JY cells. The percentage of double-positive cells is shown in the top right quadrant. The indicated experiment was performed twice with similar results.