Figure 7.
mFasL-induced bystander rejection of subcutaneous tumors was inhibited by sFasL. (A) Subcutaneous tumor growth of L5 transfectants. DBA/2 mice were injected subcutaneously with 2 × 106 L5-neo, L5-mFasL, L5-wtFasL, L5-sFasL.EX, or L5-sFasL cells and tumor size was measured periodically with a caliper. Data from two independent experiments were pooled, bars represent mean tumor size at day 11 of six to eight mice per group, and error bars represent the SD. (B) Bystander rejection of L5-neo but not L5-sFasL cells coinjected with L5-mFasL cells. DBA/2 mice were subcutaneously inoculated with a mixture of L5-neo and L5-mFasL cells. The number of L5-neo cells was kept constant at 2 × 106 cells, and L5-mFasL cells were graded from 2 × 106 to 2 × 105 cells. Tumor size was measured periodically with a caliper for 2 wk. Data represent the mean of two mice per group ± SD. Soluble sFasL inhibits bystander rejection. DBA/2 mice were subcutaneously inoculated with a mixture of 6 × 105 L5-mFasL cells and either 2 × 106 L5-neo or L5-sFasL cells. 6 × 105 L5-mFasL cells, 2 × 106 L5-neo, or 2 × 106 L5-sFasL cells were also inoculated alone as controls. Tumor growth was followed for 3 wk. Data from two independent experiments were pooled, bars represent mean tumor size at day 11 of six to nine mice per group, and error bars represent the SD.