Fig. 6: GlpT is important for intracellular replication inside macrophages.
a Replication rate inside infected Raw264.7 macrophage cells as CFUs at 24 h post-infection divided by the CFUs at 2 h post-infection after a gentamicin protection assay. The statistical significance was tested by an ordinary one-way ANOVA with Dunnet correction. The lines indicate the median. n = 3 Raw264.7 biological replicates. b Replication rate inside infected Raw264.7 macrophage cells. The Raw264.7 macrophages were primed with 2 ng/mL IFNγ for 24 h prior to infection. The lines indicate the median. The statistical significance was tested by an ordinary one-way ANOVA with Dunnet correction. n = 3 biological replicates (except for the empty vector condition where n = 2). c Plasmid retention for the experiments shown in panels a and b was quantified for the glpT mutant carrying the Pnat-glpT complementation plasmid by replica plating from LB Agar containing Streptomycin onto LB Agar with Ampicillin and then Streptomycin. The percentage of cells resistant to Ampicillin and Streptomycin is shown. The lines indicate the mean and the whiskers and the smallest and largest values, respectively. n = 3 agar plates. d The replication rates in Raw264.7 macrophage cells show that glpT is important for replication regardless of whether the strain is proficient for the canonical Pi transporters. The statistical significance was tested by an ordinary one-way ANOVA with Šidák correction. The lines indicate the median. n = 3 biological replicates. e The PgloC promoter activity suggests that the methylglyoxal pathway is less active in the glpT mutant. The lines indicate the median. The statistical significance was tested with a two-sided unpaired t-test. n = 4 biological replicates. f Normalized ratio between the glpT mutant and the wild-type in mice intraperitoneally injected with PBS (open symbols), anti-CSF1R (green), or an isogenic antibody control (black). The different shapes (circles and squares) indicate the origin of two independent experiments and the lines indicate the median. In the absence of macrophages, the glpT mutant continues to outcompete the wild-type on day 4 post-infection. The statistical significance was tested using an ordinary one-way ANOVA with Dunnet correction. n = 6 or 4 (isogenic antibody) mice. Source data are provided as a Source Data file.
