Gingipains: The Virulent Invaders

Abstract

Although nearly 400 different bacterial taxa have been identified in dental plaque samples, only a few species have been implicated as periodontal pathogens. This group of bacteria includes Porphyromonas gingivalis, Treponema denticola, Bacteroides forsythus and Actinobacillus actinomycetemcomitans. All of these organisms, with the exception of A. actinomycetemcomitans, are known to produce significant levels of proteolytic activity which, by virtue oftheir ability to cleave the trypsin-specific substratebenzoyl-L-arginine-p-nitroanilide or benzoyl-L-arginine- p-napthyl amide, have been collectively referredto as trypsin-like proteinases. Among several proteinases produced by P. gingivalis, the cysteine proteinases, referred to as gingipains, are clearly in the spotlight. Gingipains seem to be key players in subvertinghost defense systems with, significantly, the complementand neutrophils being the main target. Gingipains are potent virulence factors of P.gingivalis and are likely to be associated with development of periodontitis, therefore  gingipain inhibition by vaccination and gingipain-specific inhibitors is a useful therapy for adult periodontitis caused by P.gingivalis infection.