Figure 6. DPP-3 and TOP-1 preclude CD8⁺ T cell priming.

Titrated amounts of recombinant DPP-3 (A and B) or TOP-1 (C and D) were added to the cultures of DCs and CD8⁺ T cells together with the SF from B78OVA-FT^heat (A and C) or S8L (B and D), and T cell proliferation was analyzed. Data are representative of 3 independent experiments. Histograms represent T cell proliferation corresponding to A and C. (E and F) SF of B78OVA-FT^heat was cultured with DCs and T cells. Titrated amounts of SF from B78-FT cells transfected with control, TOP-1, or DPP-3 shRNA plasmids were added, and T cell activation was analyzed. Data are from 3 independent experiments. (G) γ-irradiated CT26OVA transfectants were cultured for 24 hours alone and then for 72 hours with CFSE-labeled OT-I cells. T cell proliferation was analyzed. Data are representative of 2 independent experiments. *P < 0.05, ***P < 0.001, 1-way ANOVA with Dunnett’s multiple-comparison test (A–D) or with Bonferroni’s paired-comparison test (E and F), or Student’s t test (G).