Fig. 2

Polyepitope neoantigen DNA vaccine elicit neoantigen-specific T cell responses in vivo. Neoantigens were identified for E0771 and 4T1.2 breast cancer models. Polyepitope neoantigen DNA vaccines were created for each and were used to immunize mice by gene gun. Spleen cells from mice vaccinated with polyepitope DNA vaccines (red) and control empty vector DNA (black) were harvested and used in IFN-γ ELISpot assay. T cell responses to selected neoantigens were shown (mean ± SEM) for Ub^mut-E0771 (a) and Ub^mut-4T1.2 (b). Of note, 8- to 10-mer minimal peptides were used in the assays for Ub^mut-E0771 (a), but 29-mer long peptides were used for Ub^mut-4T1.2 (b). Experiments were repeated at least two more times for panel a, and similar results were obtained. **P < 0.01, ***P < 0.001, t-test