Figure 1.
Syngeneic cells provide a potent adjuvant effect for CTL induction. (A) OVA/BioMag beads (5 μg) were injected s.c. into the hind flanks of C57BL/6 mice with either 105, 104, or 103 mitomycin C-treated GL261 cells, or without cells in 100 μl of PBS. Seven days later, splenocytes were harvested and stimulated with OVA-transfected EL4 cells (EG7). CTL activity was measured against EG7 cells 5 days later in a 51Cr release assay. Control mice immunized with beads alone had no detectable CTL. Killing of control EL4 cells in this assay as well as all of the following assays was minimal. (B) Similar to A except that 105 EL4 cells were used to replace GL261 cells. (C) Similar to A except that the antigen was gp120/latex beads (0.1 μg), the mice were BALB/c mice, and the coinjected cells were 5 × 105 syngeneic 3T3 cells. Mice were killed 2 weeks after the injection and splenocytes were stimulated with and assayed for killing against gp120-transfected 3T3 cells (15–12). Killing against a control cell line 18neo (control transfected 3T3) in this assay as well as all of the following assays was minimal. E:T ratio, effector-to-target cell ratio.