Peptidylarginine désiminases du microbiote buccal et polyarthrite rhumatoïde

Abstract

Ces dernières années, des études se sont focalisées sur l’existence d’une association entre la parodontite et la polyarthrite rhumatoïde (PR), suggérant l’implication du microbiote buccal dans le déclenchement de cette maladie auto-immune des articulations. D’un point de vue clinique, les deux pathologies reposent sur un processus inflammatoire qui conduit à une érosion osseuse. Elles font également intervenir une modification post-traductionnelle appelée citrullination. Dans le cas de la PR, la citrullination de certains sites protéiques par les peptidylarginine désiminases (PAD) aboutit à la production d’auto-anticorps. C’est la découverte d’une PAD exprimée par la bactérie Porphyromonas gingivalis qui a orienté de nombreuses études vers l’analyse d’une association entre ces deux pathologies.

In the last decade, the association between the periodontitis and rheumatoid arthritis (RA) has been established, suggesting that oral microbiome plays a causal role by initiating this chronic autoimmune inflammatory disease of articulation. Both pathogenesis are similar in term of chronic inflammation, tissue breakdown and bone resorption. Molecular aspects have also revealed that citrullination, a post-translational modification catalyzed by peptidyl-arginine deiminases (PADs), is involved in both diseases. For RA, citrullinated proteins production leads to the synthesis the of anti-citrullinated protein antibodies triggering the loss of immune tolerance. In humans, five PADs have been identified. Recently, studies have found that only Porphyromonas species possess PAD. Thus, a major periodontal pathogen, Porphyromonas gingivalis, is able to generate citrullinated epitopes, and could consequently induce anti-citrullinated protein antibodies. In this review, citrullination process, periodontitis and RA are described to put them in relation with molecular, clinical and epidemiological studies establishing the association between periodontitis and RA.