FIG 1 .
NhhA induces the differentiation of monocytes (Mo) into macrophages. (A to C) Human peripheral Mo were differentiated with 50 nM NhhA for 3 days. Primary Mo, macrophage colony-stimulating factor (M-CSF)-derived Mφ, and GM-CSF/IL-4-derived dendritic cells (DCs) are shown for comparison. (A) Representative differential interference contrast images of cells (original magnification, ×400). CD14 and CD1a expression of the PI-negative gate was analyzed by flow cytometry. (B) Fluorescence-activated cell sorting plots of one representative experiment. (C) Median fluorescence intensity (MFI) of CD14. Error bars indicate medians with interquartile ranges from three independent experiments. *, P < 0.05 using ANOVA followed by the Bonferroni post hoc test. (D and E) Mo were infected with wild-type (WT) or NhhA-deficient (ΔNhhA) FAM20 meningococcal strains (MOI, 10) for 3 days. Expression of CD14 and CD1a was determined by flow cytometry. (D) Representative fluorescence-activated cell sorting plots. (E) Mean ± standard deviation of the percentages of CD14hi cells from three independent experiments. Untreated Mo were used as the negative control. *, P < 0.05 using ANOVA followed by the Bonferroni post hoc test.