CTLs generated in the E6/E7 transgenic mouse have reduced cytotoxicity as compared to CTLs generated from the C57BL/6 mouse. Either six- to eight-week-old WT or transgenic mice were immunized with 1 x 10⁸ LM-LLO-E7 or 2.5 x 10⁸ LM-ActA-E7 on days zero and seven. On day 14, splenocytes were removed and cultured with irradiated TC-1 cells for 4 days. Following this culture step, splenocytes were used in a four-hour ⁵¹Cr release assay. (a and b) EL4 cells alone. (c and d) EL4 cells pulsed with 1 µM of the RAHYNIVTF peptide with differing concentrations of effector cells to target cells. (e and f) EL4 cells plus differing concentrations of peptide with an effector to target cell ratio of 50:1. Assays were preformed in triplicate with the mean number plotted and standard deviation present as error bars. Depicted is one of 2 experiments.