Focal Radiation Therapy Combined with 4-1BB Activation and CTLA-4 Blockade Yields Long-Term Survival and a Protective Antigen-Specific Memory Response in a Murine Glioma Model
Figure 6
Treatment with triple therapy results in a glioma-specific memory response.
A) Naïve mice (n = 4/group) challenged with GL261 cells in both flanks formed flank tumors in 6/8 flanks. All control animals formed GL261 flank tumors; two animals formed bilateral flank tumors and two animals formed unilateral flank tumors. B) Long-term survivors (n = 3/group) developed long-lasting immunity to GL261 tumors and successfully rejected flank tumor formation in 6/6 flanks. Mice were observed for 50 days. Each line represents tumor growth in one flank. C) Bioluminescent imaging data on day 21 after flank tumor implantation for an experiment where naïve mice (top row) and long-term survivors (bottom row) were inoculated subcutaneously with 106 GL261-luc cells in the left flank and 105 B16-luc cells in the right flank. D) Naïve mice had progressive GL261 and E) B16 flank tumor growth. Note that B16 tumors grew faster in comparison to GL261 tumors. F) Long-term survivors established a protective memory response and rejected GL261 flank tumor growth. G) Long-term survivors established a glioma-specific memory response which did not affect the formation of B16 melanoma flank tumors.