Interrupting oral infection of Porphyromonas gingivalis with anti-FimA antibody attenuates bacterial dissemination to the arthritic joint and improves experimental arthritis

Targeting the bacteria responsible for periodontal gum disease could help treat rheumatoid arthritis, according to a study in mice. Ji Hyeon Ju from the Catholic University of Korea in Seoul, South Korea, and colleagues experimentally induced arthritis in mice, and then infected the animals with a bacterium called Porphyromonas gingivalis. This pathogen causes inflammation in the tooth-supporting tissue, but it also seems to migrate from the mouth to sites of arthritis by hitching a ride on circulating immune cells in the bloodstream. Infected mice showed signs of both oral disease and joint destruction. However, pre-incubating the bacteria with an antibody drug directed at their surface appendages significantly improved both the periodontal disease and arthritis, presumably because the pathogens could no longer attach to host cells and aggregate.