Figure 5.

Immunogenic tumor cell apoptosis was induced by platinum chemotherapy in vitro. A. MC38-OVA cells were treated with Cis or Oxa (0, 100 or 200 μM) for 24 hours, followed by staining with annexin V-PE and 7-AAD. The percentages of early and late apoptotic cells were determined and the summarized data are pooled in the right panel. B. The level of HMGB1 in the cell medium of platinum-treated and untreated MC38-OVA cells was determined by ELISA. C. MC38-OVA cells were treated with Cis or Oxa for 4 hours, and calreticulin (CRT) exposure on the cell surface was assessed by immunofluorescence staining and imaging under a microscope at a magnification of 200×. D. Platinum-treated and untreated MC38-OVA cells were incubated with DCs. After 4 hours of incubation, DCs were harvested and cocultured with CFSE-labeled naïve OT-I T cells for 72 hours. Proliferation of OT-I T cells was measured by the CFSE spread on flow cytometry and quantified via calculation of the percent of CFSE⁺ OT-I cells. Error bars, SEM. **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.