Fig. 3

Mtb suppresses CXCL9/10 expression by inhibiting the STAT1 pathway. A, B THP-1 cells were transfected with NC, IDO1, STAT1, NF-κB, or CBP siRNA for 24 h, followed by IFN-γ (20 ng/mL) treatment for 24 h. Then, an ELISA of CXCL9/10 was performed. C THP-1 cells were transfected with NC, IDO1, or cotransfected with IDO1 and STAT1 siRNA for 24 h, followed by IFN-γ (20 ng/mL) treatment for 24 h. Then, qPCR of the indicated genes was performed. D THP-1 cells were transfected with NC or IDO1 siRNA for 24 h, treated with IFN-γ (20 ng/mL) for 24 h, and then treated with or without Kyn (100 μM) for 24 h. Then, the indicated antibodies were measured via western blot analysis. E THP-1 cells were cultured in complete medium and tryptophan-free medium with or without Kyn (100 μM) for 24 h, after which the indicated antibodies were used for western blot analysis. The data are presented as the means ± SDs. p values were calculated via one-way ANOVA. **p < 0.01, ***p < 0.001; ns not significant (p > 0.05)