Figure 5. Ganglioside GD3 treatment inhibits the activation of primary NKT cells.

(A) Liver MNC were harvested from C57BL/6 mice and were stained with either unloaded tetramer or α-GalCer loaded tetramer and mAbs specific for TCRβ (top panels). The CD1d-tetramer⁺TCRβ⁺ population was gated following stimulation withα–GalCer and induction of IL-4 (bottom right) or IFN-γ (bottom left) by NKT cells was assessed by flow cytometry. Data are from one experiment, representative of three independent experiments. (B) Ex vivo studies examining the effects of GD3 on α–GalCer mediated NKT cell activation. C57BL/6 mice were injected with 0.1 μg aGC, 2 μg GD3, or both. The liver MNCs were isolated and stained for intracellular IFN-γ production. (C) Primary human NKT cells were co-cultured with LCD1dwt cells pretreated with GD3.