Figure S4. Mass spectrometric analysis of eicosanoids in invariant natural killer T–monocyte culture supernatants.

Cell-free supernatants were collected from invariant natural killer T–monocyte co-cultures immediately after mixing the cells (“Time 0”) and after 24 h together in culture (“24 h co-inc”). Samples were were spiked with a known concentration of deuterated internal control (d4-PGE₂), and eicosanoid-containing fractions were prepared by organic extraction then subjected to mass spectrometric analysis. (A) Relative abundance of PGE₂ and related metabolic products produced by the COX-2 pathway in the starting sample (light bars) compared with the 24 h co-culture (dark bars). (B) Results from the same samples for products of the 5-lipoxygenase pathway.