Bacterial and human peptidylarginine deiminases: targets for inhibiting the autoimmune response in rheumatoid arthritis?
1 The Kennedy Institute of Rheumatology Division, Imperial College, 65 Aspenlea Road, London, W6 8LH, UK
2 Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, ul Gronostajowa 7, 30-387 Krakow, Poland
3 School of Dentistry, Oral Health and Systemic Disease, University of Louisville, 501 South Preston Street, Louisville, KY 40202, USA
Arthritis Research & Therapy 2010, 12:209 doi:10.1186/ar3000Published: 2 June 2010
Peptidylarginine deiminases (PADs) convert arginine within a peptide (peptidylarginine) into peptidylcitrulline. Citrullination by human PADs is important in normal physiology and inflammation. Porphyromonas gingivalis, a major pathogen in periodontitis, is the only prokaryote described to possess PAD. P. gingivalis infection may generate citrullinated peptides, which trigger anti-citrullinated peptide antibodies. In susceptible individuals, host protein citrullination by human PADs in the joint probably perpetuates antibody formation, paving the way for the development of chronic arthritis. Blockades of bacterial and human PADs may act as powerful novel therapies by inhibiting the generation of the antigens that trigger and sustain autoimmunity in rheumatoid arthritis.