Fig. 1

T. pallidum promotes macrophage polarization. a, THP-1 cells differentiated to M0 macrophages, and the morphological changes were observed by confocal microscopy (1000×). Nuclei were stained with DAPI (blue), and actin was stained with Alexa Fluor 633 phalloidin (red). Confocal laser scanning microscopy was conducted using an LSM700 confocal microscope (Zeiss, Oberkochen, Germany). b, Morphological changes in the macrophages treated with T. pallidum for 12 h (1000×). The image shows the typical morphological changes in the macrophages. The percentage of long orbicular macrophage cells among the macrophages after T. pallidum infection for 12 h was approximately 60% (data not shown). c, Cytokine mRNA levels in M0 macrophages treated with T. pallidum for 12 h. d, Cytokine protein levels in M0 macrophages treated with T. pallidum for 12 h. The results shown are from one experiment that is representative of three independent experiments and are expressed as the means±SDs. Student’s t-test was applied to compare the means between two groups. *** P < 0.001