Fig. 5: ZD55-IL-24 promotes the immune recognition of tumor cells in B16-bearing immunocompetent mouse model not due to its ability to lyse immunogenic tumor cells and release the essential elements for the induction of antitumor immunity.

A–D Fluorescence microscopic analysis of viral infection and exogenous gene expression in B16 cells. D The murine melanoma B16 cells were infected with ZD55-EGFP at a MOI (PFU/cell) of 0 and 1000, and the viral infection and exogenous gene expression were monitored under the fluorescence microscope on Day 0, Day 1, Day 2, and Day 4 after infection. D Quantification of the EGFP-positive B16 cells in A (n = 9). Error bars indicate mean ± SD. Shown is one of three independent experiments. C The appearance of cytopathic effect in A was monitored under microscope, and representative phase-contrast images were taken at the end of the experiment, and D cell viability was measured by CCK-8 assay. Results represent mean ± SEM of triplicate experiments and are expressed as a percentage of control cells. Scale bars, 300 µm. E Representative transmission electron microscopy images of B16 cells treated with ZD55-IL-24 at a MOI (PFU/cell) of 0 and 2500. Shown is one of three independent experiments. Nuclei are indicated by the black arrow. Scale bar: 4 μm. F Western blot analysis of viral infection and exogenous IL-24 expression in B16 cells infected with ZD55-IL-24 at a series of MOI (PFU/cell) as indicated. Shown is one of three independent experiments.