IL-12 synergy with TCR on NKT cells. Highly purified NKT cells were sorted from untreated liver lymphocytes (CD3⁺, NK1.1⁺), then expanded for 4 to 5 days in IL-2. Cells were evaluated for synergy, as described, using anti-CD3. IFN-γ mRNA (A) or cytokines TNFα and IFN-γ (B) or IL-2 (C) were measured in 1- and 3-hour supernatants, respectively (B-D). Values are representative of 3 experiments. (D) Liver NKT cells were obtained from untreated B6 mice and stimulated with the specific ligand αGalCer after loading into a CD1d-positive cell line A20. Cells were evaluated for synergy of cytokine production with IL-12 and αGalCer at 3 hours. TNFα, IFN-γ, or IL-2 was measured in 3-hour supernatants. Values are representative of 3 experiments.