Figure 4.

Activation of tumor-specific (gp100-specific) pmel-1 cells by immunotherapies. To increase the frequency of naive gp100-specific CD8⁺ T-cells, 5 × 10⁴ CD8⁺CD90.1⁺hgp100 tetramer⁺ cells from pmel-1 transgenic mice were adoptively transferred into IFNγ Venus mice the day before tumor challenge. Mice were then subcutaneously injected with B16 melanoma cells (5 × 10⁵). They were untreated or given 200 μg of monoclonal antibodies against PD-1, CTLA-4, 4-1BB, CD4 or the combination of anti-PD-1 and anti-4-1BB (anti-PD-1/4-1BB) on days 5 and 9. (a) Pmel-1 cells detected in the tumor, dLN, ndLN and spleen as CD8⁺CD90.1⁺ cells, showing the percentage of CD90.1⁺CD8⁺ T cells in CD45⁺ cells. (b) Absolute number of pmel-1 cells in these tissues. Steel’s test was used for multiple comparisons between control and treatment groups. (a,b).