Fig. 4

BPSP effectively caused a decrease in PD-L1 expression in Hepa1-6 cells and TAMs, improved the ratio of CTL/Tregs in tumors and promoted anti-tumor immunity. a Schematic diagram of reduction PD-L1 expression level in tumor cells and TAMs caused by NIR-II activated BPSP. b PD-L1 expression on TAMs after incubated with PBS, Free SF, BPS, and BPSP, respectively. c PD-L1 expression on Hepa1-6 cells after incubation with PBS, Free SF, BPS, and BPSP, respectively. d Immunofluorescence staining of PD-L1expression in Hepa1-6 tumors. e PD-L1 expression based on western blotting of Hepa1-6 cells and TAMs. f, g Quantitative analysis of CD3⁺CD4⁺CD8⁺ T cells in subcutaneous tumors based on FCM. h, i FCM analysis of infiltration ability of Tregs and CTLs in subcutaneous tumors. j Quantitative analysis of CD8⁺T/Tregs from subcutaneous tumors. k Quantitative analysis of cytokine levels (IL-6, IL-10, IL-12, IFN-γ, and TGF-α) in peripheral blood of subcutaneous mice based on ELISA. l) Quantitative analysis of CTLs in orthotopic tumors. m, n FCM analysis M1 TAMs and M2 TAMs in orthotopic tumors. o Cytokines (IL-12, IFN-γ) in peripheral blood of subcutaneous mouse measured based on ELISA Kit. p–r T cells, Tregs, and CTLs were quantified by flow cytometric in subcutaneous tumors. Data represented mean ± SD (n = 3). *p < 0.05, **p < 0.01, ***p < 0.001, in contrast to NS group. ^#p < 0.05, ^##p < 0.01, ^###p < 0.001, in contrast to BPSP + L group