Figure 3. In vivo effect of NIR-PIT in unilateral tumor model.
A. NIR-PIT regimen and imaging schedule are shown. B. Fluorescence images. NIR-light-exposed tumors showed immediate fluorescence decay. C. Bioluminescence images were obtained serially. D. Quantitative luciferase activity showed no significant difference between any two groups in 5 days after NIR-PIT (n = 9–10, one-way ANOVA). E. Both PIT groups suppressed tumor growth (n = 9–10, *p < 0.05, **p < 0.01, vs. Control group, one-way ANOVA followed by Tukey’s test). Further, F(ab’)2-PIT group suppressed tumor growth more strongly than IgG-PIT group (n = 10, ***p < 0.05, unpaired t-test). F. F(ab’)2-PIT group achieved significantly prolonged survival, compared with IgG-PIT group (n = 10, *p < 0.05, log-rank test). G. Evaluation of intratumoral Treg depletion one day after light exposure. Both NIR-PIT groups successfully and comparably depleted intratumoral Tregs (n = 3, *p < 0.05, one-way ANOVA followed by Tukey’s test).