Fig. 3A–C.

Antitumor effects of immunization with FCs. A We examined the antitumor effects of prior immunization with FCs on subcutaneous tumors. FC/B16 (solid circles), NIH/B16 cells (not fused with DCs; open squares), FC/CT-2A (solid squares), or NIH3T3 cells (open circles) as a control, were injected s.c. into the flank of C57/6 mice on days 0 and 7 (n=5 in each group). On day 14, 1x10⁶ B16 cells were inoculated s.c. into the flank. The administration of FC/B16 prolonged the latency period before tumor appearance, while the administration of FC/CT-2A, NIH/B16, or NIH3T3 cells did not shorten the latency period before tumor appearance. B We used FCs containing DCs and NIH/3T3 transfected with B16 genomic DNA digested with DNase (solid pyramids) or denatured DNA (open triangles) as a negative control. We also used FC/NIH (open squares). Immunization with these FCs did not shorten the latency period before tumor appearance. C NIH/3T3 cells were transfected with 2 μg (solid circles), 0.2 μg (solid squares), or 0.02 μg (open triangles) of genomic DNA from B16 cells. FCs containing DCs and each type of NIH/3T3 were identified as FC/high, FC/mid, and FC/low, respectively. No difference in antitumor effects was observed in response to immunization with FC/low or NIH3T3 (open circles), whereas immunization with FC/high or FC/mid remarkably inhibited the growth of subcutaneous tumors