IL-12 induces IFNγ-independent T-bet expression in CD8 T cells. Cells (5 × 105/mL) were stimulated, and real-time PCR for T-bet expression was normalized and expressed as percentage relative to cyclophilin A. (A) BALB/c CD8 T cells were stimulated by anti-CD3 plus anti-CD28 mAbs in combination with IL-12 or IFNγ for 3, 24, or 72 hours. (B) Stat4-deficient CD8 T cells were used. (C) OT1 CD8 T cells were stimulated with OVA peptide (5 μg/mL) and purified B cells as APCs in combination with IL-12 or IFNγ for 3, 24, or 72 hours. (D) C57BL/6 wild-type, IFNγ-deficient, IFNγR-deficient, or Stat1-deficient CD8 T cells were stimulated with anti-CD3 plus anti-CD28 mAbs in combination with IL-12 or IFNγ for 24 hours. (E) Western blotting of T-bet expression was performed on wild-type or Stat1-deficient CD8 T cells stimulated with anti-CD3 plus anti-CD28 mAbs in combination with IL-12 or IFNγ for 24 hours. Data shown are one representative of 3 independent experiments; standard errors of PCR triplicates are shown.
