FIG 6.

K. pneumoniae drives macrophage polarization in a STAT6-dependent manner. (A) CD163 surface expression in mock-infected (PBS) or Kp52145-infected pBMDMs by flow cytometry. Values are shown as the means ± SEM from two independent experiments in duplicate. **, P < 0.01, determined by unpaired Student’s t test. (B) Immunoblotting analysis of phosphorylation of STAT6 (PSTAT6) and tubulin in lysates of pBMDMs infected with Kp52145 for the indicated times or left noninfected (ni). Data are representative of those from three independent experiments. (C) cd163 levels in pBMDMs left noninfected or infected with Kp52145 pretreated with STAT6 inhibitor (AS1517499, 50 nM, 2 h prior to infection) or DMSO vehicle control. Values are shown as the means ± SEM from three independent experiments. (D) Arginase-1 levels in pBMDMs left noninfected or infected with Kp52145 pretreated with STAT6 inhibitor (AS1517499, 50 nM, 2 h prior to infection) or DMSO vehicle control. Values are shown as the means ± SEM from three independent experiments. (E) Immunoblotting analysis of phosphorylation of STAT6 (PSTAT6) and tubulin in lysates of pBMDMs infected with Kp52145 and strain 52145-Δwca_K2 for the indicated times or left noninfected. Data are representative of those from three independent experiments. (F) cd163 levels in pBMDMs left noninfected or infected with strain 52145-Δwca_K2 pretreated with STAT6 inhibitor (AS1517499, 50 nM 2 h prior to infection) or DMSO vehicle control. Values are shown as the means ± SEM from three independent experiments in duplicate. (G) arginase-1 levels in pBMDMs left noninfected or infected with strain 52145-Δwca_K2 pretreated with STAT6 inhibitor (AS1517499, 50 nM, 2 h prior to infection) or DMSO vehicle control. Values are shown as the means ± SEM from three independent experiments in duplicate. In panels C and D, significant difference was determined for the indicated comparisons using one-way ANOVA with Bonferroni correction. ***, P < 0.001; **, P < 0.01.