Figure 3.

(A) Properties of NK-T cells observed in the IL-15Tg mouse. Lymphocytes were isolated and purified from the liver. (Left) The NK-T population (FL1, FITC–anti-CD3ɛ; FL2, phycoerythrin–anti-NK1.1). Gated cells were further analyzed in the FL3 channel by the indicated antibodies (for CD8β, biotin–αCD8β/Cychrome–Streptavidin were used). As a control, preferential CD4 staining seen with the wt liver NK-T cells is shown. (B) Induction of CD8 NK-T cells from the bone marrow precursors of wt mice. Bone marrow cells were cultured with 10 nM IL-2 or IL-15. At day 6 and following, there was a propagation of NK and NK-T cells. The NK-T cells were further analyzed for their CD8 expression, which was >85% as shown as the histogram. (C) Production of γIFN but not IL-4 by the CD8 NK-T cells after stimulation examined by an RNase protection assay. NK-T cells were purified from a bone marrow culture using negative selection using the anti-CD8β antibody. NK-T cells and total spleen lymphocytes were stimulated by phorbol-myristate acetate (15 ng/ml) and ionomycin (0.75 μM) for 24 h before RNA extraction.