Inhibition of Actinomyces viscosus – Porphyromonas gingivalis coadhesion by trypsin and other proteins

Abstract

Protease activity is associated with the coadhesion of Actinomyces viscosus and Porphyromonas gingivalis. To try to distinguish whether the recognition/adhesion or degradative functions of proteases are more crucial for coadhesion, we determined the effect of trypsin and other purchased proteases and proteins on coadhesion when they were incorporated in the coadhesion assay buffer or when A. viscosus cells were pretreated with trypsin. Coadhesion was measured by the decrease in turbidity caused by the absorption of A. viscosus cells from aqueous suspension by P. gingivalis-coated hexadecane droplets. Pretreatment of A. viscosus with trypsin had no obvious effect on the kinetics of coadhesion. Likewise, trypsinization of A. viscosus failed to aid or enhance coaggregation by chemically induced, trypsin activity-deficient mutants of B. gingivalis. In contrast, incorporating trypsin in the buffer during the coadhesion assay yielded a concentration-dependent inhibition of coadhesion greater than the inhibition found with the same concentration of other proteases. Coadhesion was also impaired to a greater extent by similar wt/vol concentrations of nonproteolytic proteins (bovine serum albumin (BSA), defatted BSA, gelatin, and casein), by antisera against whole P. gingivalis cells and fimbriae, by preimmune serum, and by the amino acid arginine but not lysine. These findings suggest that the role of proteases in coadhesion is not solely to enzymatically "prime" A. viscosus for more avid coadhesion and that their role as potential protein or peptide seeking adhesins should be considered.

Coaggregation of Porphyromonas gingivalis and Prevotella intermedia

“…The involvement of P. gingivalis fimbriae in the coaggregation of the former two combinations has been suggested. Coaggregation of P. gingivalis and A. viscosus is inhibited by the same cysteine protease inhibitors that suppressed coaggregation of P. gingivalis and P. intermedia (6,17).…”

Glyceraldehyde-3-Phosphate Dehydrogenase of Streptococcus oralis Functions as a Coadhesin for Porphyromonas gingivalis Major Fimbriae

“…In order to cause infection, it is necessary for P. gingivalis to attach to tooth surfaces, subgingival epithelium, or early colonizing gram-positive bacteria; this step constitutes the initial stage of colonization in periodontal pockets (38). In addition, the bacterium has been reported to interact with a variety of other oral gram-positive bacteria (19), including Actinomyces naeslundii (36,43), Actinomyces viscosus (9,12,26,27,36), Streptococcus gordonii (23), Streptococcus mutans (17), Streptococcus oralis (29), and Streptococcus sanguis (39); these interactions are considered to play a vital role in the colonization of P. gingivalis in the oral cavity.…”

Porphyromonas gingivalis Fimbriae Mediate Coaggregation with Streptococcus oralis through Specific Domains

“…This bacterium reportedly aggregates with various oral Gram-positive plaque-forming organisms such as Actinomyces viscosus (Schwarz et al, 1987;Li and Ellen, 1989;Li et al, 1991;Ellen et al, 1992), Streptococcus gordonii (sanguis) (Lamont et al, 1993(Lamont et al, , 1994Stinson et al, 1991), mutans streptococci (Kamaguchi et al, 1994), and S. oralis (mitis) (Nagata et al, 1990;Murakami et al, 1991). Cohesive interactions between P. gingivalis and other bacteria are thought to play an important role in the colonization of P. gingivalis in periodontal sites.…”