A. WT B6 mice were immunized with ERAAP-KO spleen cells, or B. ERAAP-KO mice were immunized with WT spleen cells. Spleens from immunized mice were harvested after ten days and restimulated in vitro with the same APCs used for immunization. The resulting CD8 T cell responses to the indicated APCs were measured as intracellular IFNγ production. Forward and side scatter were used to exclude dead and granular cells, and the cells in the resulting lymphocyte gate were B220-CD4-CD8α+TCRβ+. Each point represents a different mouse responding to splenic APCs of the indicated genotype. . The data are presented as the mean of five mice, with the bars representing standard error of the mean. When analyzed by non-parametric one way ANOVA (Kruskal-Wallis with Dunn’s post-test), the data are statistically significant, with p=0.0157 and p=0.0169 for Fig A and B respectively.