Figure 2. The Polar Lipid Fraction of Ascites inhibits NKT cell activation.
The polar lipid fraction was isolated from the ascites of ovarian cancer patients. LCD1dwt cells were treated with ascites or the polar lipid fraction of the ascites for 4 h, then washed extensively and cocultured with a panel of NKT cell hybridomas. (A) IL-2 production was measured as an indication of NKT cell activation. Data are shown as mean ±S.E.M. In addition, treatment with the polar lipid fraction significantly inhibited all hybridomas examined (p<0.001). (B) GM-CSF production was measured as an indication of NKT cell activation. Data shown as mean ±S.E.M. (C) TLC of the Polar Lipid Fraction. The extracted lipids were analyzed by TLC. Gangliosides were detected with a resorcinol–HCl Cu2+ reagent. Bovine brain gangliosides were used as standards as indicated at the left. Tumor gangliosides typically appear as doublets due to heterogeneity in their ceramide lipid moieties.