Figure 5.

Acquisition of lysotracker by green fluorescent protein (GFP) Mycobacterium tuberculosis–containing phagosomes and reactive oxygen generation was reduced in infected fat-1 macrophages. Phagosomal maturation was defined based on lysotracker colocalization and visualized by fluorescent microscopy, as described in the Materials and Methods. A, Representative images of the reduced colocalization in fat-1 macrophages, compared with wild-type (WT) macrophages. Data are representative of 3 independent experiments. B, Quantitative data show the percentage of lysotracker-positive mycobacterial phagosomes in fat-1 and WT cells. Reactive oxygen intermediates were estimated by FACS, as described in the Materials and Methods. C, Representative density plots of reduced respiratory burst in infected fat-1 macrophages. The analysis was restricted to the cell population in density plots and the region R2 was created for events with high intensity of red dihydroethidium (EB) fluorescence. The percentage of events in that region was determined by CellQuest. The basal level of oxidized EB due to metabolic activity of control uninfected cells was used to set gates. Data are representative of 3 independent experiments. D, Quantitative data show the relative percentage of EB red fluorescence. *P < .001; **P < .01.