Figure 6. Proteasome stimulation enhances T cell tumor immunity.

A) Proteasome activity of purified CD8⁺ splenocytes treated for 4 hours with cyclosporine A (CsA) or MG-132. B) Western blot analysis and band quantification or C) quantification of protein synthesis rates from IL-2 effector T cells conditioned with CsA or vehicle control prior to seeding in the tumor-T cell transwell assay. D) Tumor growth rate and E) overall survival from adoptive transfer of 7-day expanded vehicle or CsA conditioned OT-1 T cells infused to C57BL/6 mice bearing 7-day established B16-F1-OVA melanomas. Frequency of adoptively transferred F) CD45.2⁺ OT1 or G) Thy1.1⁺ pmel T cells infused as in D-E harvested from B16-F1-OVA or B16-F1 melanomas 5 days post transfer, respectively. Data are representative of one to three independent experiments. p values are noted in each panel based on statistical analysis by one way ANOVA with Tukey’s multiple comparison correction (A, C) two tailed Student’s t-test (B, F-G) or mixed linear regression (D) and log-rank, mantel-cox test of survival proportions (E), (N = 4-8 mice per group), all error bars indicate the SEM.