Fig. 1.

B7-H1 on DCs has an opposite effect on T cell responses to dominant and subdominant Ags. (A and B) Naive OT-1 and H-Y T cells were transferred into mice and immunized with DCs purified from WT or B7-H1–KO male/OVA-Tg mice. After 5 d, spleen cells were analyzed by flow cytometry. (A and B) Representative plots (A) and absolute number (B) of OT-1 and H-Y T cells in spleens. (C and D) B6 mice were immunized s.c. with gp100 and TRP2 coloaded WT or B7-H1–KO DCs. At day 8, spleen cells were restimulated with the peptide in vitro. (C) IFN-γ⁺CD8⁺ T cells were counted. (D) Concentrations of IFN-γ in cultured supernatants detected by ELISA. Results represent at least three experiments unless otherwise stated. *P < 0.05 and **P < 0.01, determined by Student’s t test. Error bars indicate SD.