Two hours after infection, the level of HA-labeled JAM1 in the cells of the lower layer was decreased by administration of bacterial culture supernatant from P. gingivalis WT, but not by the mutant, whereas the mCherry signal was not decreased by administration of culture supernatant from either strain (S14B Fig), indicating that JAM1 protein in the lower cells was degraded by secreted gingipains, but expression of the JAM1 gene was not downregulated. This evidence concerns the gene F11R and infection.