Fig. 6
In vivo Trabectedin treatment induced PD-L1 expression within ID8 tumors. a Mice were inoculated i.p. with 1 × 106 ID8 cells and treated with control or Trabectedin on day 10 and 17. On day 19, harvested tumor cells from treated mice were stained with APC conjugated anti-PD-L1 (black or red line for control or Trabectedin treatment) or isotype control antibody (filled gray line) for evaluating PD-L1 expression by flow cytometry. In vitro cultured ID8 tumor cells were included as a control (blue line). b Mice were treated as described in a, and harvested tumor tissues were analyzed for PD-L1 expression by immunofluorescence staining. Iso denotes isotype control staining. c In vitro cultured ID8 tumor cells were treated with peritoneal lavage fluid (20%, v/v) prepared from control (black line) or Trabectedin (red line) treated mice for 24 h and PD-L1 expression was then analyzed by flow cytometry (upper panels). In some experiments, ID8 tumor cells treated with peritoneal lavage fluid from Trabectedin treated mice were cultured in the presence of isotype or α-IFN-γ neutralizing antibody (bottom panels). Untreated ID8 cells were included as a control (blue line). Data are representative of two independent experiments.