Immunization of BMT recipients increases survival and GVT activity.
One month after BMT, SW→B6 recipients were immunized with 205IL-2/TK cells and ganciclovir. Two weeks after the first vaccine, micrometastases were established by intravenous injection of 1 × 105 205 tumor cells, at which time 1 group of recipients received a second vaccine. Lung nodules were counted at the time of death or after day 100 for each recipient. The deaths that occurred in the recipient group immunized twice resulted from the growth of a nonpulmonary metastasis (sacral/pelvic mass) that necessitated sacrifice. Groups and sizes were: no vaccine, n = 4; 1 vaccine, n = 5; and 2 vaccines, n = 5. *P < .05 for lung nodules compared to 1 or no vaccine controls. **P = .004 compared to nonimmunized recipient survival.
