A Lactotransferrin Single Nucleotide Polymorphism Demonstrates Biological Activity That Can Reduce Susceptibility to Caries

Abstract

bStreptococcus mutans is prominently linked to dental caries. Saliva's influence on caries is incompletely understood. Our goal was to identify a salivary protein with anti-S. mutans activity, characterize its genotype, and determine genotypic variants associated with S. mutans activity and reduced caries. An S. mutans affinity column was used to isolate active moieties from saliva obtained from a subject with minimal caries. The bound and eluted protein was identified as lactotransferrin (LTF) by matrixassisted laser desorption ionization-time of flight (MALDI-TOF) analysis and confirmed by Western blotting with LTF antibody. A single nucleotide polymorphism (SNP) that produced a shift from arginine (R) to lysine (K) at amino acid position 47 in the LTF antimicrobial region (rs: 1126478) killed S. mutans in vitro. Saliva from a subject with moderate caries and with the LTF "wild-type" R form at position 47 had no such activity. A pilot genetic study (n ‫؍‬ 30) showed that KK subjects were more likely to have anti-S. mutans activity than RR subjects (P ‫؍‬ 0.001; relative risk ‫؍‬ 3.6; 95% confidence interval [95% CI] ‫؍‬ 1.5 to 11.13). Pretreatment of KK saliva with antibody to LTF reduced S. mutans killing in a dose-dependent manner (P ‫؍‬ 0.02). KK subjects were less likely to have caries (P ‫؍‬ 0.02). A synthetic 11-mer LTF/K peptide killed S. mutans and other caries-related bacteria, while the LTF/R peptide had no effect (P ‫؍‬ 0.01). Our results provide functional evidence that the LTF/K variant results in both anti-S. mutans activity and reduced decay. We suggest that the LTF/K variant can influence oral microbial ecology in general and caries-provoking microbes specifically.

Lactoferrin

“…While the Brazilian study appears to confirm the anti-S. mutans laboratory data reported above (Velliyagounder et al 2003), note that occlusal and proximal caries were not separated in the Brazilian study (Azevedo et al 2010). Saliva collected from an LAP subject was passed through a S. mutans affinity column to isolate, capture, and identify the active anticaries fraction (Fine, Toruner, et al 2013). The salivary protein that remained bound to the column containing S. mutans-coated beads was eluted and identified as lactoferrin by MALDI-TOF mass spectroscopy and confirmed by Western blot using human antibody to lactoferrin (Fig.…”

“…Protection (as in the case of caries) can come in the form of direct antimicrobial action on the disease-provoking members of the microflora (Fine, Toruner, et al 2013). Alternatively, host-related components that interact with the biofilm community can produce an environment that can influence overall biofilm composition and stability unfavorably but indirectly and thus alter the clinical outcome (Nibali et al 2014).…”

“…In addition, growth of Lactobacillus, Actinomyces, and Veillonella species was also reduced. Taken together, while the clinical data are limited in subject numbers, the information obtained suggests that the lysine variant of lactoferrin could directly affect growth of microbes related to proximal caries development and that those individuals with this variant have minimal proximal decay (Fine, Toruner, et al 2013). …”

Salivary protein polymorphisms and risk of dental caries: a systematic review

“…About half of the selected studies analyzed children, 13,14,18,19,20 evaluating primary and permanent dentition, while the other half studied only adults. 12,15,21,22,23,24 Dental caries prevalence was evaluated according to the number of decayed, missing, and filled teeth. There has been no distinction between primary (dmft) and permanent (DMFT) dentition for indexing low and high risk of caries.…”

A Consortium of Aggregatibacter actinomycetemcomitans, Streptococcus parasanguinis, and Filifactor alocis Is Present in Sites Prior to Bone Loss in a Longitudinal Study of Localized Aggressive Periodontitis

“…While we have ignored the effect of the host response in the presentation of these data, we firmly believe that a variety of host factors can influence microbial patterns related to periodontal disease. For example, a lactotransferrin lysine-to-arginine polymorphism at amino acid position 47 has been shown to affect the microbial composition of dental plaque by influencing the survival of acid-producing bacteria related to caries (35). We will report in the future on host factors that were collected for analysis in this longitudinal study.…”