Figure 6. Allogeneic CD4⁺ T cells could not help CD8⁺ T cells eradicate tumors in the absence of MHCII expression by the host.

PRO4L-SIY-EGFP tumor-bearing MHCII^−/− Rag^−/− B6 mice were treated with sorted 2C CD8⁺ T cells (arrows) and sorted CD4⁺ T cells from CD8^−/− B6 mice at the indicated times (red dots). Data were pooled from 3 independent experiments. Only 1/7 total mice rejected the tumor.