Figure 3.

Cytolytic activities of in vitro-derived alloreactive Tc cells from gzmA, gzmB, gzmA×B, and perforin KO and B6 mice, and target cell survival after Tc cell assay. Splenocytes from B6, perf^−/−, gzmA^−/−, gzmB^−/−, gzmA×B^−/−, and perf×gzmA^−/− mice were cocultured with HTG stimulator cells for 5 days and assayed for their ability to induce ⁵¹Cr release in L1210 target cells (shaded bars). Effector to target cell ratio was 5:1, derived from a regression analysis from a 4-fold titration curve (r values always >0.95). All values were from triplicate wells. Assay time was 6 h. Cells from a duplicate assay set up with unlabeled target cells were transferred after 6 h into 2-ml Costar plates in Eagle’s minimal essential medium with 2% FCS in the absence of 2-mercaptoethanol. Negative control wells contained effectors without target cells. After 4 days, the wells were spiked with [³H]thymidine for 6 h, cells were harvested, and radioactivity was measured (filled bars).