Fig 3

Gingipains prevent phagosome acidification of internalized Porphyromonas gingivalis (Pg).

Real-time in vivo examination of the acidification of the wild-type Pg W83 and ΔK/R-ab. Pg were stained with fluorescein-SE (green) and pHrodo (red) and zebrafish larvae (30 hpf) were infected into the Duct of Cuvier. Representative images along with quantification of the phagosome-acidified bacteria within selected area and size of acidified bacterial clusters in the yolk (A and C) or the tail regions (B and D) at 2 hpi (A and B) or 24 hpi (C and D). White dashed lines indicate yolk or tail areas. Boxes show zoomed regions of the images. y = yolk, h = heart. Scale bar = 100 μm. Data presented are means ± SD. Each dot represents signal quantified from a single zebrafish larva. Statistical significance was analysed by unpaired t-test with Welch’s correction or Mann-Whitney test where required. *≤0.05, **p≤0.01, ****p≤0.0001.