Fig. 8. ICIE generates long-term antitumor memory immune response and inhibits metastasis in the lung.

a A schematic illustration of the in vivo experimental design. Mice received an intravenous injection of various formulations every 3 days. Cryosurgery was performed on the orthotopic tumor (OT) at 8 h after the first injection of the various formulations. The lung metastasis model was induced by intravenous injection of 4T1 cancer cells on day 10 after the first injection of the different formulations. b Weight of lungs collected from mice at the end of the study, suggesting inhibition of lung metastasis by ICIE (n = 6 mice). c Representative photographs of lung tissues isolated at the end of the study, showing inhibition of lung metastasis by the ICIE treatment. Scale bar: 1 mm. d Quantification of lung metastasis nodes per mouse from mice at the end of the study (n = 6 mice). e Representative H&E staining images of lung tissues collected at the end of the study, showing the decreased formation of metastasis in the lungs of mice with the ICIE treatment. Scale bar: 1 mm for low-magnification images and 200 µm for zoom-in images. The areas circled by blue dashed lines are metastases in the lungs. The experiments were repeated three times independently (n = 3 mice) with similar results. f The percentage of effector memory T cells (T_EM, CD3⁺CD8⁺CD44⁺CD62L⁻) in blood collected from mice with the various treatments (n = 3 mice). Statistical analyses were performed using one-way ANOVA with Tukey’s multiple comparisons test and correction. Data are presented as mean ± SD (b, d, f). Source data are provided as a Source Data file.