Figure 1.

Interferon (IFN)‐γ production was not detected in interleukin (IL)‐4^−/– mice by injection of α‐galactosylceramide (α‐GalCer). (a) C57BL/6‐background wild‐type (wt) mice and IL‐4^−/– mice were intravenously administrated with 2 µg α‐GalCer. Serum levels of IFN‐γ (○, □) and IL‐4 (•, ▴) in wt mice (○, •) and IL‐4^−/– mice (□, ▴) were determined by enzyme‐linked immunosorbent assay 1, 2 and 4 h after the injection. The bars represent mean ± SE of three mice in each group. (b) Hepatic lymphocytes prepared from wt mice and IL‐4^−/– mice were stained with APC‐Anti‐NK1.1 and PerCp‐anti‐CD3 monoclonal antibodies (mAb). NK1.1⁺ CD3⁺ natural killer (NK) T cells were gated. The numbers mean the percentage of NKT cells among whole hepatic lymphocytes.