Figure 2.

Targeting of S1P₁ signaling enhances NKT cell-mediated cytotoxicity of MCL. (A) Jeko and (B) SP53 cells were incubated with 10 µM SEW2871 or W146 for 72 h, washed, and co-cultured with primary NKT cells at the indicated ratios in the presence of α-GalCer (100 ng/mL) for 24 h and NKT cell mediated cell lysis was assessed by standard ⁵¹Cr-release assay. (C) MCL cell lines express S1P receptors. Expression of S1P₁ and S1P₄ was determined by RT-PCR after incubation with 10 µM SEW2871 (S1P1 agonist) or the S1P₁ antagonist, W146, for 72 h. Expression was quantitated using densitometry for S1P1 and S1P4 in (D) Jeko and (E) SP53 relative to B-actin. (F) IFN-γ levels were determined by ELISA. Data are representative of three independent experiments. Data were analyzed by one-way ANOVA. ** p < 0.001.