FIG. 4.

Representative fluorescence microscopy images demonstrating LVSgfp localization within EEA1- or LAMP-1-containing endosomes in TC-1 cells. Images depict TC-1 cells stained for EEA1 30 min after inoculation with LVSgfp (A) or 2 h postinoculation stained for LAMP-1 (B). Single-color images: LVSgfp images depict bacteria alone, EEA1 and LAMP-1 images depict staining for EEA1 or LAMP-1 only, and extracellular images depict staining of extracellular bacteria (no extracellular bacteria were present in panel B). The merged color images depict LVSgfp (green), vacuoles labeled with anti-EEA1 antibody (N19) (red) or anti-LAMP-1 (1D4B) (red), or extracellular LVS labeled with anti-F. tularensis LPS antibody conjugated to Pacific Blue (blue). Extracellular LVSgfp (arrow with round end), intracellular but not EEA1-associated LVSgfp (small arrow), and LVS associated with EEA1-containing vacuoles (large arrowhead). (C) Trafficking of LVSgfp in TC-1 cells. One hundred intracellular bacteria were counted for each condition and scored for association with EEA1- and LAMP-1-containing vacuoles. Three replicates were examined for each time point and condition.