Saliva Protein Binding to Layers of Oral Streptococci in vitro and in vivo

Abstract

This paper reports a system for measuring saliva protein binding to oral streptococci. Enamel chips with layers of Streptococcus gordonii Blackburn or Streptococcus oralis 10557 were incubated in vitro with whole saliva from eight persons. Blackburn bound significantly more amylase than 10557; no strain differences were seen for lysozyme or lactoferrin. There were significant correlations between saliva and bound amylase and lactoferrin. Blackburn and 10557 chips were then placed in ten subjects. Sites included the buccal left and right upper premolars and molars (UL, UR), labial upper central incisors (UC), and lingual lower central incisors (LL). That study was repeated three months later; chips with Streptococcus sanguis 13379 were also placed then. Blackburn bound significantly more amylase than the other strains. Blackburn and 10557 both bound the most amylase at UL and UR, and the least amylase at UC. However, strain 13379 bound less amylase at UL. That strain also bound significantly less sIgA at UL. All three strains bound the least sIgA at UC. Lysozyme and lactoferrin binding showed few differences among sites or strains. Bound protein concentrations were significantly correlated across sites and strains within subjects, but not correlated with whole saliva. Strain differences may reflect species differences in amylase binding, or differences in species-specific sIgA titers. Site differences may indicate local variation in protein availability. Differences between chip correlations with whole saliva in vitro and in vivo suggest that the salivary film may be modified as it flows over tooth surfaces.

Does Variability in Salivary Protein Concentrations Influence Oral Microbial Ecology and Oral Health?

“…S. gordonii expresses an amylase receptor, and that strain bound the most amylase. However, the S. oralis strain also bound some amylase, despite the absence of any known amylase receptor (Rudney et al, 1995). Amylase recovered from that strain may have been complexed with a protein such as MG2, which does bind many S. oralis strains (Murray et al, 1992).…”

“…Recent findings suggest that regional variation may affect salivary protein interaction with oral bacteria (Rudney et al, 1995). Layers of oral streptococci were placed on buccal surfaces of left and right upper molars, buccal surfaces of upper central incisors, and lingual surfaces of lower central incisors.…”

“…It also facilitates collection of site-specific samples (Liljemark et al, 1988;Skopek et al, 1993). That may be very important in view of the finding that salivary protein binding by bacteria differs between oral sites (Rudney et al, 1995). Regional measurement of both saliva and plaque could provide a more definitive test of the hypothesis that salivary proteins exert selective effects on the oral flora.…”

Streptococcus gordoniiHsa Environmentally Constrains Competitive Binding byStreptococcus sanguinisto Saliva-Coated Hydroxyapatite

“…Salivary pellicle constituents identified as putative receptors for S. sanguinis can also be utilized by S. gordonii and vice versa. Such receptors include proline-rich proteins (5,40), glycoproteins (31,40,49), salivary agglutinin (3, 9), secretory immunoglobulin A (sIgA) (24,39), lysozyme (38,55), and lactoferrin (38). An ability to bind directly to ␣-amylase has been shown for S. gordonii and is lacking for S. sanguinis (45), while S. sanguinis has been shown to utilize a binding site formed by a complex of ␣-amylase and the light chain of sIgA (7).…”

Establishment of an Animal Model Using Recombinant NOD.B10.D2Mice To Study Initial Adhesion of Oral Streptococci

“…The ability of oral streptococci to bind to salivary pellicle proteins on the tooth surface is of considerable etiological significance (28,33), and S. mutans and S. sanguis are known to be primarily involved with the formation of bacterial flora on teeth. S. sanguis and S. mitis are early colonizers of the salivary pellicle, while S. mutans colonizes later; however, the ability of each to bind to salivary proteins and glycoproteins is strong and important in biofilm development (19,40).…”