B7.2-AML cells have reduced tumorigenicity but do not elicit systemic immunity. (A) SJL/J mice (8 to 10 mice for each type of experiment) were injected IV with 105 or 106B7.2-AML cells or 105 control cells. These experiments were repeated twice. Mice injected with (▪) 105 B7.2-AML cells rejected their tumor, whereas mice injected with (○) 106B7.2-AML or (▴) control cells developed lethal leukemia. (B) SJL/J mice were immunized IV with (▪) 105 irradiated (3,200 cGy) B7.2-AML or (○) 2 × 106 B7.2-AML cells or (▵) control cells (solid arrow) and 2 weeks later challenged with 105 live wild-type AML cells (open arrow). Challenge was lethal to all groups of vaccinated mice. Vaccinations with 2 × 106 irradiated B7.2-AML cells prolonged survival for 5 to 7 days.
