Fig. 6.

Dendritic cells respond to silica by mitochondrial and cellular stress associated with dsDNA leakage and STING activation. a, b WT and STING^−/− bone marrow-derived DCs were unstimulated or stimulated with silica (250 µg/mL) for 18 h. a Flow cytometry using MitoSOX staining of mitochondria-derived superoxide production on pre-gated singlet cells (SSC-A/SSC-H) and CD11b⁺CD11c⁺F4/80^– DCs. Histograms and mean fluorescence intensity (MFI) quantification. b Flow cytometry Annexin V/PI staining showing early apoptotic (Ann V⁺/PI⁻) versus late apoptotic/necrotic (Ann V⁺/PI⁺) DCs. c Concentration of extracellular dsDNA in culture supernatant. d Immunoblots of caspase 3, cleaved caspase 3, gasdermin D, MLKL, and phospho-MLKL in WT and STING^−/− DCs with β-actin as a reference. e Confocal images of DNA dye Draq5 (cyan) and STING-specific antibody (red) in WT DCs stimulated as in a, b or transfected with c-di-AMP (6 µg/mL; cDN) for 18 h as a positive control. Bars, 20 µm. f WT DC immunoblots of STING/IRF3 axis including phospho-STING, STING, phospho-TBK1, TBK1, phospho-IRF3, and IRF3, with β-actin as a reference. *p < 0.05, **p < 0.01, ****p < 0.0001 (Mann–Whitney U analysis). Data are presented as mean ± SEM and are representative of two independent experiments with similar results (a, c, d) or with n = 3 independent cultures (a, b, e). Immunoblots are representative of n = 9 samples from three independent experiments (d, f). Source data are provided as a Source Data file