Fig. 1.

Effect of intratumoral administration of DCs with conditional expression of combination of different cytokines on tumor growth. a Mice bearing RENCA tumors, with an average size of about 50 mm², were separated into different treatment groups on day 10 after tumor inoculation. DC-IL-12 were injected on day 10 and the administration of AL started on day 9 and continued for 15 days. Each group included 7–10 mice. Differences between mice, treated with DC-IL-12+ AL chow and all control groups, were statistically significant (P < 0.03). b, c Experiments were performed essentially the same way as in Fig. 1a, with the exception of the use of DC-IL-21 (b) or DC-INF-α (c) instead of DC-IL-12. Each group included 6–8 mice. The differences between the DC-IL-21 + AL or DC-IFN-α + AL groups and the controls group were statistically significant (P = 0.01 and P < 0.001, respectively). d, e Mice with established RENCA tumor were treated with i.t. injection of DC-IL-12 on day 14, followed by administration of DC-IL-21 (d) or DC-IFN-α (e) 4 days later. AL was administered from day 13 until day 31. Each group included 6–8 mice. The differences between the combination cytokines + AL groups and all control groups were significant (P < 0.04). However, no differences were seen with DC-IL-12 + AL group (P > 0.1)