Genetic control of susceptibility to Porphyromonas gingivalis-induced alveolar bone loss in mice

Periodontal disease affects a large percentage of the human population. Resorption of the alveolar bone of the jaw is a pivotal sequela of periodontal disease, because this bone is the attachment site for the periodontal ligaments that anchor the teeth. Using a murine model in which alveolar bone loss is induced by oral infection with Porphyromonas gingivalis, a gram-negative bacterium associated with human adult periodontal disease, we provide evidence suggesting that susceptibility to such bone loss is a genetically determined trait. AKR/J, DBA/2J, and BALB/cByJ or BALB/cJ mice were highly susceptible, while A/J, A/HeJ, 129/J, SJL/J and C57BL/6J mice were much more resistant. When susceptible BALB/cJ and BALB/cByJ mice were crossed to resistant strains, two patterns were observed. (BALBc/ByJ x C57BL/6J)F-1 offspring were susceptible, suggesting C57BL/6J has recessive resistance alleles, while (BALB/cJ x A/J)F-1 mice were all resistant, suggesting that A/J mice have dominant resistance alleles, These results suggest a tractable genetic basis for P. gingivalis-induced alveolar bone loss and open the possibility of exploiting the mouse model to identify loci important for host susceptibility and resistance to periodontal disease.