Figure 6.
GVL activity is not significantly impaired in ICOS-/- T cells. (A) B6 into B6D2F1 and challenge with P815. B6D2F1 mice were lethally irradiated (1300 cGy) and received transplants with TCD B6 allo-HSCs (5 × 106). The tumor challenge control group was not infused with T cells and received 1 × 103 P815 cells (• P815) (n = 4). Control groups for GVHD received a dose of 1 × 106 WT or ICOS-/- B6 T cells (▪ WT and ▴ ICOS-/-)(n = 10) and no tumor challenge. GVL groups received 0.5 × 106 WT (▪) or ICOS-/- (▴) B6 T cells and were challenged with a separate intravenous injection containing 1 × 103 P815 cells (n = 10). Statistical analyses: • versus ▪, P = .02; and • versus ▴, P = .003. The cause of death (GVHD versus tumor) for the GVL groups is shown in Table 1. Shown are combined data from 2 independent experiments. (B) B6 into BALB/c and challenge with A20. BALB/c recipients were lethally irradiated (900 cGy split) and received transplants with TCD B6 allo-HSCs (5 × 106). The tumor challenge control group was not infused with T cells and received 2 × 106 A20 cells (•; n = 8). GVL groups received 0.5 × 106 WT (▪) or ICOS-/- (▴; n = 16) B6 T cells and were challenged in a separate intravenous injection with 2 × 106 A20 cells (▪,n = 18; ▴,n = 10). Shown are data combined from 2 independent experiments. Statistical analyses: • versus ▪ and • versus ▴, P < .001. The cause of death (GVHD versus tumor) for the GVL groups is shown in Table 1. (C) B6→BALB/c and challenge with A20-TGL. BALB/c recipients were lethally irradiated (900 cGy split) and received transplants with TCD B6 allo-HSCs (•)(5 × 106). The tumor challenge control group was not infused with T cells and received 0.5 × 106 A20-TGL cells (•;n = 4). GVL groups received 0.5 × 106 WT (▪) or ICOS-/- (▴) B6 T cells and were challenged with a separate intravenous injection containing 0.5 × 106 A20-TGL cells. (D) Mice were tracked for in vivo luminescence using firefly luciferin injected intraperitoneally, and bioluminescence was determined on days 8, 14, and 110. Mice shown are representative of the entire group. The cause of death (GVHD versus tumor) for the GVL groups is shown in Table 1.