Timing Is Critical for an Effective Anti-Metastatic Immunotherapy: The Decisive Role of IFNγ/STAT1-Mediated Activation of Autophagy
Figure 1
Prophylactic, but not therapeutic, administration of the complex attenuates pulmonary metastasis of B16 melanoma cells.
C57BL/6 mice were injected i.v. with B16-F10 melanoma cells (5×105/mouse) and administered with the TLR4 agonist EC-LPS (12.5 µg/kg) plus the TLR9 agonist CpG ODN (0.25 mg/kg) i.p. every 3rd day for 3 doses before (prophylactic group) or after (therapeutic group) tumor cell inoculation. Control animals were treated with PBS or EC-LPS plus CpG ODN with an identical dosage and frequency as indicated in prophylactic group. The mice were humanely sacrificed, and their lungs were excised 14 days after tumor cell inoculation. Externally visible melanoma nodules on the lung surface were counted using stereo microscopy. (A) Kaplan-Meier graph representing the cumulative survival of mice in the indicated treatment groups. The data were analyzed using Kaplan-Meier survival analysis (n = 15 per group). (B) The metastatic nodules were counted and data presented as the mean ± S.E. (n = 15). (C) Data are representative lung samples (upper panel) and representative H&E staining of lung sections (below panel) (magnification: 100×). (D) The expression of cleaved caspase-3 and PCNA was detected by western blot (left panel) and corresponding quantification (right panel) in lung tissues 14 days after inoculation. Data are presented as the mean ± S.E. (n = 5 mice per group).