PG27 inhibited IL-2 production from activated T cells in a concentration-dependent manner. Human peripheral blood T cells at a concentration of 1 × 106/mL were pretreated with various concentrations of PG27 for 2 h and then stimulated with PMA + ionomycin (shown as P + I) (A) or CD3/CD28 (B) for 24 h. The supernatants were collected for the determination of IL-2 concentrations. In parallel, cell survival in the various conditions was determined by trypan blue exclusion assays (C). The results shown are from independent experiments. Each experiment was performed in triplicate using T cells from at least 3 different donors.