Innate immunity glycoprotein gp-340 variants may modulate human susceptibility to dental caries.

Anette Jonasson,Carina Källestål,Ingegerd Johansson,Howard F Jenkinson,Christer Eriksson,Nicklas Strömberg

doi:10.1186/1471-2334-7-57

Abstract

BackgroundBacterial adhesion is an important determinant of colonization and infection, including dental caries. The salivary scavenger receptor cysteine-rich glycoprotein gp-340, which mediates adhesion of Streptococcus mutans (implicated in caries), harbours three major size variants, designated gp-340 I to III, each specific to an individual saliva. Here we have examined the association of the gp-340 I to III polymorphisms with caries experience and adhesion of S. mutans.MethodsA case-referent study was performed in 12-year-old Swedish children with high (n = 19) or low (n = 19) caries experiences. We measured the gp-340 I to III saliva phenotypes and correlated those with multiple outcome measures for caries experience and saliva adhesion of S. mutans using the partial least squares (PLS) multivariate projection technique. In addition, we used traditional statistics and 2-year caries increment to verify the established PLS associations, and bacterial adhesion to purified gp-340 I to III proteins to support possible mechanisms.ResultsAll except one subject were typed as gp-340 I to III (10, 23 and 4, respectively). The gp-340 I phenotype correlated positively with caries experience (VIP = 1.37) and saliva adhesion of S. mutans Ingbritt (VIP = 1.47). The gp-340 II and III phenotypes tended to behave in the opposite way. Moreover, the gp-340 I phenotype tended to show an increased 2-year caries increment compared to phenotypes II/III. Purified gp-340 I protein mediated markedly higher adhesion of S. mutans strains Ingbritt and NG8 and Lactococcus lactis expressing AgI/II adhesins (SpaP or PAc) compared to gp-340 II and III proteins. In addition, the gp-340 I protein appeared over represented in subjects positive for Db, an allelic acidic PRP variant associated with caries, and subjects positive for both gp-340 I and Db tended to experience more caries than those negative for both proteins.ConclusionGp-340 I behaves as a caries susceptibility protein.

Highlights

Bacterial adhesion is an important determinant of colonization and infection, including dental caries
We have shown salivary agglutinin to be identical to the scavenger receptor cysteine-rich glycoprotein gp-340 [9] and found three prevalent size variants of saliva gp-340, designated gp-340 I to III, each specific to individual donors [25]
The results reveal a positive association of gp-340 I with both caries experience and saliva adhesion of S. mutans, and that purified gp-340 I protein mediates increased antigen I/II (AgI/II)-mediated adhesion of S. mutans

Summary

Introduction

Bacterial adhesion is an important determinant of colonization and infection, including dental caries. The salivary scavenger receptor cysteine-rich glycoprotein gp-340, which mediates adhesion of Streptococcus mutans (implicated in caries), harbours three major size variants, designated gp-340 I to III, each specific to an individual saliva. Caries prone subjects coincided with increased saliva adhesion of S. mutans and Db, a low prevalence allelic acidic PRP variant [10]. We have shown salivary agglutinin to be identical to the scavenger receptor cysteine-rich glycoprotein gp-340 [9] and found three prevalent size variants of saliva gp-340, designated gp-340 I to III, each specific to individual donors [25]. The gp-340 I to III size polymorphisms have not been investigated as relates to susceptibility or resistance to dental caries or to differences in AgI/II-mediated adhesion of S. mutans

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