Fig. 4: Evaluation of enhanced ferroptosis induced by HGF-relative exosomal PD-L1 inhibition.

a In vitro schedule for ferroptosis-relevant tests. b Relative IFN-γ release from CD8⁺ T cells incubated in different conditions. n = 5 biologically independent samples per group. c Relative lipid ROS of B16F10 cells co-cultured with CD8⁺ T cells after incubating in PBS, HACA-Fe, HACA-GW, and HGF NPs for 48 h. n = 5 biologically independent samples per group. d CLSM observation of expression of SLC7A11 and SLC3A2 in B16F10 cells treated with PBS, HGF or HGF + IFN-γ for 24 h. Scale bar: 20 μm. Experiments were performed three times independently with similar results. e GPX4 activity in B16F10 cells co-cultured with CD8⁺ T cells after incubating in PBS, HACA-Fe, HACA-GW, and HGF NPs. n = 5 biologically independent samples per group. f Schematic showing the experiment design for in vivo evaluations (g–o). n = 5 biologically independent animals per group. g The intratumoral IFN-γ level after treatment. G1, PBS; G2, HACA-Fe; G3, HACA-GW; G4, HGF. h IFN-γ secretion in serum. i and j Flow cytometric quantification of IFN-γ⁺ T cells after gating on CD3⁺CD8⁺ T cells (i) and CD3⁺CD4⁺ T cells (j) in TDLN. k Immunofluorescence assay for the expression of SLC7A11 and SLC3A2 in tumor tissues. Scale bar: 50 μm. l–o Cystine (l), GSH (m), GPX4 activation (n), and lipid ROS (o) levels in B16F10 tumor tissue after treatment. All data are presented as mean ± SD. Statistically significant differences between groups were identified by one-way ANOVA with Tukey’s post hoc test. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.