Figure 4.

Immune response mechanism of DHU‐CBA2 with PDT via alleviating the high concentration of PGE₂ and IDO1. A) Relative mRNA levels of Ptgs2, B) protein level of COX‐2, and C) the level of PGE₂ in the supernatant in LLC cells with MB (+). (+) represents low‐dose laser irradiation in vitro. Experimental data in (A and C) were presented as mean ± SD. Statistical significance was calculated via one‐way ANOVA with Tukey's test. (n = 3 replicates, ^* p < 0.05, ^** p < 0.01, ^*** p < 0.001). D) The protein level of PGE₂ in LLC‐bearing subcutaneous tumors by various treatments (1: CTRL; 2: DHU‐CBA3; 3: DHU‐CBA2; 4: DHU‐CBA3 (+); 5: DHU‐CBA2 (+); “(+)” represents laser irradiation). Experimental data were presented as mean ± SD. Statistical significance was calculated via one‐way ANOVA with Tukey's test. (n = 3 individual animals per group, ^* p < 0.05, ^** p < 0.01, ^*** p < 0.001). E) Association between CTL levels and overall survival of patients with lung cancer with different IDO1 gene copy numbers. Continuous z = 2.59; P = 0.00956. Z‐scores and p‐values were computed by the two‐sided Wald test in Cox‐PH regression. F) Representative images of IDO1 expression in subcutaneous tumors after various treatments by immunohistochemistry staining analysis. G) CD3⁺CD8⁺, and H) GranB⁺CD8⁺ T cells in subcutaneous tumors after various treatments were detected and quantified by flow cytometry. Experimental data in (G,H) were presented as mean ± SD. Statistical significance was calculated via one‐way ANOVA with Tukey's test. (n = 3 individual animals per group, ^* p < 0.05, ^** p < 0.01, ^*** p < 0.001).