Fig. 5: SAA upregulates OSM production in neutrophils and reduces IFN-γ and TNF release in autologous CD8⁺ T cells.

a, b The mRNA expression of genes associated with N2 phenotype neutrophils is increased in SAA (1 μg/mL)-treated neutrophils including OSM, ARG1, IL-1B, and IL-10 by qPCR. n = 10 biologically independent samples. c The correlated protein expression of genes including PD-L1, OSM, ARG1, and IL-1β is validated in SAA (1 μg/mL)-treated neutrophils by western blotting analysis. n = 3 independent samples (d) The level of OSM and ARG1 is determined in SAA (1 μg/mL)-treated neutrophils by ELISA. n = 10 biologically independent samples. e Paraffin-embedded HCC samples are double-stained with anti-human MPO antibody (green) and anti-human OSM antibody (red). n = 10 patients. The OSM⁺MPO⁺ cells are observed in the peritumoral region by confocal microscopy. f Neutrophils treated with medium, SAA (1 μg/mL), OSM-SMI-10B (50 μmol/L) and SAA (1 μg/mL) plus OSM-SMI-10B (50 μmol/L) for 12 h are used to co-culture with autologous CD8⁺ T cells. The levels of IFN-γ and TNF production in CD8⁺ T cells were analyzed after 12 h of co-culture by flow cytometry. n = 3 biologically independent samples. Statistical data presented in this figure show mean ± SEM. ns indicates P > 0.05, *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001, by two-sided Student’s t test (b, d, f), or one-way ANOVA (e). Source data and exact P values are provided as a Source Data file.