Oral Pathogen ‘Neutralizes’ the Human Innate Immune Defence

Our present findings show for the first time that the virulence factor PPAD protects the oral pathogen P. gingivalis against neutrophil insults at three distinct levels, namely phagocytosis, NETosis and CAMP activity. This identifies PPAD as a major agent in the evasion of human innate immunity, a view that is supported by studies from Potempa and co-workers showing PPAD-dependent citrullination of complement29. Why is this important? Every day, millions of people lose teeth due to periodontitis. This has a serious impact on their quality of life, not only for aesthetic reasons but much more so because tooth loss causes difficulties in eating and interferes with interpersonal communication. Yet, only few people realize that there is a major bacteriological component in periodontitis where our immune defences are breached with potentially serious implications, especially systemic and chronic diseases ranging from bacteraemia to rheumatoid arthritis.