One hour after infection, the level of HA-labeled JAM1 in IHGE cells in the lower layer was decreased by infection with P. gingivalis WT relative to the mutant, whereas the mCherry signal was not decreased by infection with either strain (Fig 8D), indicating that JAM1 proteins in the lower cells were degraded by P. gingivalis gingipains, but gene expression was not downregulated. This evidence concerns the gene F11R and infection.