Long-term protection can be achieved with anti-CD40 but not other mAb specificities. (A) Groups of 5 age-matched CBA mice were inoculated with 106 A31 tumor cells intravenously on day 0 and were treated with 5 Gy TBI (as before), together with 0.25, 0.5, or 1 mg anti-CD40 mAb intravenously. Control animals received PBS. Treatment was as indicated. (B) Groups of 5 CBA mice were inoculated with A31 as before and treated with combinations of 5 Gy TBI with or without mAb to a panel of B-cell markers (CD19, CD22, MHC II as indicated; all 1 mg intravenously). All animals were fed acidified water substituted with neomycin sulfate as before. Survival was recorded daily. When given in combination with TBI, long-term protection can be achieved with anti-CD40 mAb (but not other mAb specificities) at doses that are nontherapeutic when given as a single agent. Similar data were obtained in at least 2 independent experiments.
