Porphyromonas gingivalis gingipain is involved in the detachment and aggregation of Aggregatibacter actinomycetemcomitans biofilm

Abstract

Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans are major periodontal pathogens that cause several types of periodontal disease. Our previous study suggested that P. gingivalis gingipains secreted in the subgingival environment are related to the detachment of A.actinomycetemcomitans biofilms. However, it remains unclear whether arginine-specific cysteine proteinase (Rgp) and lysine-specific proteinase (Kgp) play different roles in the detachment of A. actinomycetemcomitans biofilm. The aim of this study was to investigate possible disruptive roles of Kgp and Rgp in the aggregation and attachment of A. actinomycetemcomitans. While P. gingivalis ATCC33277 culture supernatant has an ability to decrease autoaggregation and coaggregation of A. actinomycetemcomitans cells, neither the boiled culture supernatant of ATCC33277 nor the culture supernatant of KDP136 showed this ability. The addition of KYT-1 and KYT-36, specific inhibitors of Rgp and Kgp, respectively, showed no influence on the ability of P. gingivalis culture supernatant. The result of gelatin zymography suggested that other proteases processed by gingipains mediated the decrease of A. actinomycetemcomitans aggregations. We also examined the biofilm-destructive effect of gingipains by assessing the detachment of A. actinomycetemcomitans from polystyrene surfaces. Scanning electron microscope analysis indicated that A. actinomycetemcomitans cells were detached by P. gingivalis Kgp. The quantity of A. actinomycetemcomitans in biofilm was decreased in co-culture with P. gingivalis. However, this was not found after the addition of KYT-36. These findings suggest that Kgp is a critical component for the detachment and decrease of A. actinomycetemcomitans biofilms.

Aggregatibacter actinomycetemcomitans: Virulence of its leukotoxin and association with aggressive periodontitis

“…72 In addition, P. gingivalis displays a competitive advantage over A. actinomycetemcomitans in co-cultured biofilms by inhibiting the growth and attachment of the A. actinomycetemcomitans cells. 73,74 These findings are supported by the negative association in subgingival samples between the presence of A. actinomycetemcomitans and P. gingivalis. 75 This indicates an important pre-clinical role of A. actinomycetemcomitans in AgP.…”

Linkages between oral commensal bacteria and atherosclerotic plaques in coronary artery disease patients

“…66 Simultaneously, Porphyromonas ginigvalis acts to detach A. actinomycetemcomitans from within the biofilms with the help of Kgp. 67 Thus, bacteria can invade healthy gingival crevices by detaching and distorting the already existing oral biofilm. This can damage connective tissue, periodontal ligament, and bone with the help of bacterially secreted peptides and proteases, thereby allowing the bug access to bloodstream.…”

Zebrafish as a new model to study effects of periodontal pathogens on cardiovascular diseases

“…Recently, small peptide analogs (KYT-1 and KYT-36) that are selective inhibitors of Kgp and Rgp, respectively4748 have been developed. These inhibitors have been shown to suppress the pathogenic potential of Pg in murine models24.…”