Journal: Cell Communication and Signaling : CCS
Article Title: PD-L1 mediates M1 polarization of macrophages via the AIM2/IL-18/STAT1 signaling axis during sepsis
doi: 10.1186/s12964-025-02578-1
Figure Lengend Snippet: Triple-verification strategy (gene silencing/antibody neutralization/site-directed mutagenesis) confirms regulatory hierarchy of PD-L1/AIM2/IL-18/STAT1 signaling axis in macrophage M1 polarization. A PD-L1 HI /THP-1-M and PD-L1 NC /THP-1-M cells were pretreated with AIM2-targeting siRNA or scramble siRNA (scr siRNA) prior to 24 h LPS (100 ng/ml) + IFN-γ (20 ng/ml) co-stimulation, with subsequent Western blotting analysis of STAT1 phosphorylation. B - C Anti-IL-18 neutralizing antibody (1 µg/ml) and isotype control (1 µg/ml) were pretreated for 24 h followed by LPS + IFN-γ 24 h co-stimulation. B qRT-PCR quantification of IFN-γ mRNA ( n = 3 independent biological replicates). C STAT1 phosphorylation profiling by Western blotting. D Truncation mutant validation: LPS + IFN-γ-stimulated (24 h) PD-L1 Δ35–90 cells analyzed for STAT1 activation vs. full length type. E Following AIM2 silencing in PD-L1 HI /THP-1-M and PD-L1 NC /THP-1-M cells, qRT-PCR quantification of IL-6, IL-27 and NOS2 mRNA after 24 h LPS + IFN-γ stimulation ( n = 3 independent biological replicates). F Post IL-18 neutralization, mRNA levels of IL-6, IL-27 and NOS2 were assessed by qRT-PCR under LPS + IFN-γ 24 h stimulation ( n = 3 independent biological replicates). G STAT1-silenced cells were analyzed for IL-6/IL-27/NOS2 transcriptional changes post 24 h LPS + IFN-γ exposure ( n = 3 independent biological replicates). H Truncated PD-L1 Δ35–90 mutants were evaluated for IL-6, IL-27 and NOS2 mRNA expression following LPS + IFN-γ 24 h challenge ( n = 3 independent biological replicates). The data are presented as the mean ± SEM. Statistical analysis for B, E, F, G and H was performed by Student’s t-test. * p < 0.05
Article Snippet: IL-27, IL-6, IL-18, and IFN-γ concentrations in cell supernatants or plasma were quantified using ELISA kits (Boster Biological Technology; Wuhan, China) with absorbance measurements at 450 nm.
Techniques: Neutralization, Mutagenesis, Western Blot, Phospho-proteomics, Control, Quantitative RT-PCR, Biomarker Discovery, Activation Assay, Expressing