Role of the Porphyromonas gingivalis InlJ protein in homotypic and heterotypic biofilm development

The oral pathogen Porphyromonas gingivalis expresses a homolog of the internalin family protein InIJ. Inactivation of inlJ reduced monospecies biofilm formation by P. gingivalis. In contrast, heterotypic P. gingivalis-Streptococcus gordonii biofilm formation was enhanced in the InlJ-deficient mutant. The results indicate a nuanced role for InIJ in regulating biofilm accumulations of P. gingivalis.