Fig. 5.

Cytotoxic T lymphocyte (CTL) assay. Cytotoxic activity of activated spleen cells was tested in vitro with a standard ⁵¹Cr-release assay 3 weeks after tumor-cell inoculation. Splenocytes were co-cultured with irradiated RT-2 cells for 5 days; then, cells were harvested and cytotoxic T cell (CTL) activity was determined with the ⁵¹Cr-labeled RT-2 cells as target cells. Three independent experiments were done for each group, and representative data were presented