Figure 5.

Analysis of TRP-2^180–188–specific CD8⁺ T cells in vaccinated mice. (A) Blood lymphocytes were stained on day 17 after tumor challenge for the presence of TRP-2^180–188–specific CD8⁺ T cells using an APC-conjugated TRP-2^180–188 K^b-tetramer and anti–CD8-FITC. The percentage of TRP-2^180–188–specific CD8⁺ T cells of total CD8⁺ T cells is indicated. Treatments of mice were as follows: group 1, naive mice; groups 2–8, B16-BL6 tumor challenge on day 0; groups 3–7, vaccination on days 0, 3, and 6 with GM-CSF–producing B16. If indicated, 200 μg blocking anti–CTLA-4 Ab was injected on days 0, 3, and 6, depleting anti-CD25 Ab (450 μg) was injected at day −4. Significant difference (P = 0.03, Student's t test) was found between mice from groups 3 and 4. Error bars indicate the SD of three measurements from one experiment. One representative experiment of two is shown. (B) Lymph node cells were stained on day 17 after tumor challenge for the presence of TRP-2–specific IFN-γ–producing CD8⁺ T cells. Results indicate the percentage of TRP-2–specific CD8⁺ T cells from the total CD8 population calculated as (percentage of TRP-2 responders) − (percentage of E1A responders). A representative result from two experiments is shown.