Figure 2.

hCD1d presents α-GalCer to mouse and human NK T cells. (A and B) Response of a Vα14/Vβ8 hybridoma. hCD1d-transfected cells (A20 hCD1d), mCD1.1-transfected cells (A20 mCD1), or untransfected A20 cells were pulsed for 2 h either with α-GalCer or the vehicle control. These APCs were washed twice and plated at 10⁵ cells/well. Antibodies at 10 μg/ml were added immediately before the addition of either the 3C3 (Vα14/Vβ8) or the DN3A4-1-4 (Vα14/Vβ10) T cell hybridomas at 5 × 10⁴ cells/well. After 16 h of culture, IL-2 release was determined by ELISA. The experiments shown here are representative of four different experiments. (C) Response of a human Vα24/Vβ11 clone. hCD1d CIR transfectants (C1R hCD1d), hCD1d-transfected Hela cells (Hela hCD1d), or the untransfected parental control cells were antigen pulsed as described above. Cells were then incubated for 48 h with T cells from clone 15.21.2 at 5 × 10⁴ cells/well. Isotype-matched control or anti-hCD1d mAb 51.1 at 20 μg/ml were added immediately before the addition of the T cells. IFN-γ and IL-4 release were determined by ELISA. The experiments shown here have been performed without the addition of PMA, and they are representative of three different experiments.