Vaccination with DCs loaded with irradiated, mAb-coated tumor cells protects against a lethal inoculum of 38C13 lymphoma. (A) Groups of mice were vaccinated on days −28 and −14 with DCs cocultured with irradiated, anti-Id mAb-coated 38C13 tumor cells (n = 12), DCs cocultured with tumor cells alone (n = 11), or Id-KLH protein (n = 12). Mice were challenged with 1000 38C13 subcutaneously on day 0, followed for tumor growth, and killed when tumors reached 1.4 cm in diameter. (B) Groups of 10 mice were vaccinated on days −28 and −14 with DCs loaded with mAb-coated tumor cells, DCs loaded with untreated tumor cells, DCs alone, irradiated tumor cells alone, or Id-KLH protein. Mice were challenged with 5000 38C13 tumor cells subcutaneously on day 0, followed for tumor growth, and killed when tumors reached 1.4 cm in diameter. (C) Groups of mice were vaccinated on days −28 and −14 with DCs cocultured with irradiated, anti-Id mAb-coated 38C13 tumor cells (n = 12), DCs cocultured with tumor cells incubated with irrelevant isotype control antibody (n = 12), DCs cocultured with tumor cells alone (n = 12), or HBSS (n = 8). Mice were challenged with 5000 38C13 subcutaneously on day 0, followed for tumor growth, and killed when tumors reached 1.4 cm in diameter.