Fig. 1

Immunization against B16 tumor cells expressing MAGE-1 and MAGE-3 by subcutaneous injection of genetically modified embryonic fibroblasts
C57BL/6J mice (n = 5–20) were injected subcutaneously with 3 × 106 embryonic fibroblasts infected with control retroviral vector (EF-SFG, □) or retroviral vector encoding MAGE-1 (EF-MAGE-1, ♦) or MAGE-3 (EF-MAGE-3, O). Two weeks later, animals were injected subcutaneously on the back with 1.25 × 106 B16 melanoma cells expressing (A) MAGE-1, (B) MAGE-3, or (C) SIV tat. Tumor development was monitored every 3 days and animals were sacrificed when the sum of the two tumor diameters reached 30 mm (a tumor volume of about 1.7 cm3) or when tumors became ulcerated.