Ag loading and ISS activation of FL-mobilized DCs induce tumor protection and regression of established tumors.

(A,C) Experimental design. Groups of 5 mice were immunized with 9 daily injections of FL followed by 1 SC injection of OVA mixed with ISS, C-ODN, or PBS on day 0. The mice were challenged with one SC injection of 1 × 10⁴ B16-OVA melanoma tumor cells in the opposite flank 1 and 7 weeks following immunization (tumor prevention) or 3 days prior to the first FL injection (tumor treatment). (B) Kaplan-Meier graphs showing the tumor-free survival of mice treated as described in panel A. Results shown are representative of 3 separate experiments. ● indicates FL-ISS-OVA (1 tumor challenge); ○, FL-ISS-OVA (rechallenge); ▴, FL–C-ODN–OVA; ▵, FL-OVA; ♦, ISS-OVA; ■, OVA alone. (D,E) Kaplan-Meier graphs showing the tumor-free survival of mice treated as described in panel C. These graphs are the results of 2 separate experiments. Statistically significant differences in tumor-free survival were found between mice treated with FL plus ISS plus OVA compared to control groups in both the tumor prevention (P = .0002) and the 2 tumor treatment experiments (P = .004). There was no statistical difference in tumor-free survival between FL plus OVA or FL plus OVA plus C-ODN and the control groups (P > .1) in any of the experiments. In panels D-E, ● indicates FL-ISS-OVA; ○, FL-ISS; ▴, FL–C-ODN–OVA; ▵, FL-OVA; ♦, ISS-OVA; ■, OVA alone.