Comparison of primary and long-term self/TERT-specific CD8 T-cell responses in mice immunized with lv-hTERT vector or with pY572/adjuv. Spleen lymphocytes from HHD mice immunized with recombinant lv-hTERT or with pY572/adjuv 10 days later were stained ex vivo either with pY572/pentamer or with irrelevant HIVgag/pentamer (N = 3-6 mice per group). Control mice were vaccinated with lv-GFP (empty vector). Representative fluorescence-activated cell sorter (FACS) plots of pentamer staining are presented (A left), and the mean percentages of pY572/pentamer⁺ CD8 T cells after subtraction of irrelevant pentamer are shown (A right). (B) Freshly isolated spleen CD8 T cells were cultured with p572 or pY572 peptide (5 μg/mL), and the IFN-γ–producing CD8 T cells were detected by IFN-γ ELISpot. The mean of specific IFN-γ spots plus or minus SD in each group are shown (n = 6 mice/group). The long-lasting responses are measured 30 days after the respective immunization with pentamer and IFN-γ ELISpot done ex vivo. (C) Representative FACS plots of pentamer staining and the mean of pY572/pentamer⁺ CD8 T cells are presented (n = 6 mice/group). (D) The mean of IFN-γ–producing CD8 T cells in response to p572 or pY572 peptide are shown (n = 4 mice/group). *Statistically significant value (P < .05, Mann-Whitney test).