GVT activity after tumor immunization of BMT recipients is tumor-specific in vivo.
One month after BMT, SW→ B6 recipients were immunized twice with irradiated C1498 leukemia cells (C1498-immune) or were irradiated 205IL-2/TK cells (205-immune) at a 1-week interval. Control recipients (nonimmune) were not immunized. Ten days after the 2nd vaccine, 1.5 × 104 C1498 cells (A) or 1 × 105 205 cells (B, C) were injected intravenously to simulate relapse after BMT, and immune recipients were immunized twice more at 1-week intervals. Lung nodules were counted in the 205-challenged mice at the time of death or after 100 days. Although tumor immunization against either 205 or C1498 induced protection (P < .05) against the immunizing cell type, it did not induce cross-protection against the other tumor (P > .05 for both survival tests and lung nodules). Results were pooled from 2 independent experiments.
