Estimation of sCD14 levels in saliva obtained from patients with various periodontal conditions

Toll-Like Receptors and Dental Mesenchymal Stromal Cells

Dental mesenchymal stromal cells (MSCs) are a promising tool for clinical application in and beyond dentistry. These cells possess multilineage differentiation potential and immunomodulatory properties. Due to their localization in the oral cavity, these cells could sometimes be exposed to different bacteria and viruses. Dental MSCs express various Toll-like receptors (TLRs), and therefore, they can recognize different microorganisms. The engagement of TLRs in dental MSCs by various ligands might change their properties and function. The differentiation capacity of dental MSCs might be either inhibited or enhanced by TLRs ligands depending on their nature and concentrations. Activation of TLR signaling in dental MSCs induces the production of proinflammatory mediators. Additionally, TLR ligands alter the immunomodulatory ability of dental MSCs, but this aspect is still poorly explored. Understanding the role of TLR signaling in dental MSCs physiology is essential to assess their role in oral homeostasis, inflammatory diseases, and tissue regeneration.

sCD14 Level in Saliva of Children and Adolescents with and without Dental Caries, a Hurdle Model

Objective: Soluble CD14 (sCD14) plays an important role in the innate immune response of the oral cavity. The investigation of this biomarker for detection of carious lesions is an even more actual procedure due to its non-invasiveness and the ease of withdrawal. The purpose of the present observational case-control study was to evaluate whether the quantification of sCD14 in children and adolescent’s saliva can discriminate healthy subjects from those suffering from tooth decay. Materials and Methods: 164 subjects (6 to 17 years) were selected and divided into 2 groups: those with at least 1 decayed tooth were assigned to group Decayed (n = 82) and those free from dental caries to group Healthy (n = 82). The amount of salivary soluble CD14 was quantified. Results: Mean salivary soluble CD14 was 28.3 ± 10.8 μg/mL in the Healthy group and 22 ± 9.6 μg/mL in the Decayed group. A hurdle model was applied to the data to estimate both the probability of having carious lesions and their number in relation to sCD14 levels. sCD14 was strongly associated (p < 0.01) with an inverse relation to both the probability of having caries and their number (falling rate of 5% per unit CD14 μg/mL). Conclusions: This data confirms the relationship between sCD14 and the presence of dental caries. However, there is no clear cut off level between healthy and unhealthy subjects, so it is currently not possible to use sCD14 as a biomarker to determine the risk of decays.

Oral Dysbiosis and Autoimmunity: From Local Periodontal Responses to an Imbalanced Systemic Immunity. A Review

The current paradigm of onset and progression of periodontitis includes oral dysbiosis directed by inflammophilic bacteria, leading to altered resolution of inflammation and lack of regulation of the inflammatory responses. In the construction of explanatory models of the etiopathogenesis of periodontal disease, autoimmune mechanisms were among the first to be explored and historically, for more than five decades, they have been described in an isolated manner as part of the tissue damage process observed in periodontitis, however direct participation of these mechanisms in the tissue damage is still controversial. Autoimmunity is affected by genetic and environmental factors, leading to an imbalance between the effector and regulatory responses, mostly associated with failed resolution mechanisms. However, dysbiosis/infection and chronic inflammation could trigger autoimmunity by several mechanisms including bystander activation, dysregulation of toll-like receptors, amplification of autoimmunity by cytokines, epitope spreading, autoantigens complementarity, autoantigens overproduction, microbial translocation, molecular mimicry, superantigens, and activation or inhibition of receptors related to autoimmunity by microorganisms. Even though autoreactivity in periodontitis is biologically plausible, the associated mechanisms could be related to non-pathologic responses which could even explain non-recognized physiological functions. In this review we shall discuss from a descriptive point of view, the autoimmune mechanisms related to periodontitis physio-pathogenesis and the participation of oral dysbiosis on local periodontal autoimmune responses as well as on different systemic inflammatory diseases.

Estimation of soluble CD14 levels in gingival crevicular fluid and serum in diseased and healthy periodontium

OBJECTIVE

To estimate the levels of sCD14 in gingival crevicular fluid and serum under periodontally-healthy and diseased conditions.

METHODS

The subjects were divided into three groups of 15, each as follows: healthy, gingivitis, and periodontitis. Periodontal parameters including Probing pocket depth, Clinical attachment level, Bleeding index, and Plaque index. Gingival crevicular fluid and serum samples were collected and analyzed for sCD14 levels using commercially-available ELISA kits.

RESULTS

The mean concentration of sCD14 in GCF was significantly lower in the gingivitis (134.5 ± 26.85 ng/mL) and periodontitis (103.23 ± 20.36 ng/mL) groups than in the healthy group (172.77 ± 46.33 ng/mL); p < 0.001. The mean serum concentration of sCD14 in the healthy group was 1528.13 ± 387.37 ng/mL, which was significantly less than that of the periodontitis group (2051.50 ± 381.10 ng/mL); p = 0.011.

CONCLUSIONS

The serum sCD14 levels in the periodontitis groups were significantly higher than those in the healthy controls. The levels of sCD14 in GCF were significantly lower in the gingivitis and periodontitis groups than in the healthy group.

Changes in salivary microbial sensing proteins CD14 and TLR2 with aging

OBJECTIVE

Soluble toll-like receptor-2 (sTLR2) and soluble CD14 (sCD14) in saliva are defense proteins that bind specific microbe-associated molecular patterns. Since the oral flora changes with aging, the objective of this study is to determine and compare the concentration of sTLR2 and sCD14 in the saliva of healthy individuals in age groups from the first to the sixth decade of life.

METHODS

Unstimulated whole saliva was collected after obtaining informed consent. The concentration of sCD14 and sTLR-2 was measured by enzyme-linked immunosorbent assay. Statistical differences between the age groups were determined by analysis of variance. The relationship between the two markers in each age group was evaluated by Pearson's correlation coefficient and linear regression analyses.

RESULTS

The concentration of salivary sTLR2 was highest in the youngest, and that of the sCD14 was highest in the oldest age group. While the salivary sCD14 and the sTLR2 exhibited a moderate negative correlation in the youngest, the relationship between the two markers was inversed in the oldest age group.

CONCLUSIONS AND CLINICAL RELEVANCE

The results of our exploratory study suggest a need to adjust for age-dependent changes in sCD14 and sTLR2 in healthy saliva while assessing the two proteins as biomarkers.

Salivary levels of specialized pro-resolving lipid mediators as indicators of periodontal health/disease status

AIM

This cross-sectional case-control study aimed to determine if salivary levels of lipoxin A4 (LXA4), protectin D1 (PD1), resolvin E1 (RvE1) and maresin 1 (MaR1) might constitute a reflection of periodontal health/disease status.

MATERIALS AND METHODS

One hundred and two periodontitis patients and 61 healthy controls were recruited. Periodontal clinical status was determined by criteria based on full-mouth clinico-radiographical data. Salivary concentration of the analytes was calculated by enzyme-linked immunosorbent assay. The association between the biomarkers with disease status was assessed individually and adjusted for confounding using multivariate binary logistic regression models.

RESULTS

Significantly decreased LXA4 and increased PD1/MaR1 salivary levels were detected in periodontitis patients in comparison with healthy controls. However, no significant differences were observed for RvE1 levels between clinical groups. Clinical parameters such as probing depth, clinical attachment loss and extent were negatively correlated with LXA4, positively correlated with PD1/MaR1 and not correlated with RvE1 salivary levels. Logistic regression analyses revealed a strong/independent association of LXA4, PD1 and MaR1 salivary levels regarding disease status. Interaction effects between demographic predictor variables and salivary concentration of LXA4, PD1 and MaR1 were also identified.

CONCLUSION

The results of this study demonstrated a strong/independent association between reduced LXA4 and increased PD1/MaR1 salivary levels with periodontitis suggesting an imbalance in the specialized pro-resolving lipid mediators (SPMs) in periodontal disease.

Soluble CD14 Enhances the Response of Periodontal Ligament Stem Cells to Toll-Like Receptor 2 Agonists

Human periodontal ligament stem cells (hPDLSCs) do not express membrane-bound CD14, and their responsiveness to bacterial lipopolysaccharide (LPS) is drastically enhanced by soluble CD14 (sCD14), which is due to the facilitation of the interaction between LPS and Toll-like receptor- (TLR-) 4. Several studies also show that sCD14 enhances the responsiveness of different immune cells to TLR-2, but such effect in hPDLSCs has not been studied so far. In the present study, we investigated for the first time the potential effect of sCD14 on the hPDLSC response to two different TLR-2 agonists, in vitro. Primary hPDLSCs were stimulated with synthetic lipopeptide Pam3CSK4 or lipoteichoic acid (LTA) in concentrations 1-1000 ng/ml in the presence/absence of sCD14 (250 ng/ml). Additionally, the effect of different sCD14 concentrations (2.5-250 ng/ml) on the TLR-2 response was determined in Pam3CSK4- or LTA-triggered hPDLSCs. The resulting expression of interleukin- (IL-) 6, chemokine C-X-C motif ligand 8 (CXCL8), and chemokine C-C motif ligand 2 (CCL2) was measured by qPCR and ELISA. The production of IL-6, CXCL8, and CCL2 was gradually increased by both TLR-2 agonists and was significantly enhanced by sCD14. The response of hPDLSCs to low and submaximal concentrations of TLR-2 agonists (1-100 ng/ml) was most effectively enhanced by sCD14. The effect of sCD14 on TLR-2 response in hPDLSCs was concentration-dependent and was already detectable at low sCD14 levels. Our data showed that exogenous sCD14 significantly enhanced the responsiveness of hPDLSCs to TLR-2 agonists and enabled the detection of their small amounts. This effect was already detectable at low sCD14 levels, which are comparable to those in saliva and gingival crevicular fluid. Changes in the local sCD14 level may be considered as a crucial factor influencing the susceptibility of hPDLSCs to different pathogens and thus may contribute to the progression of periodontitis.

Differential profiles of soluble and cellular toll like receptor (TLR)-2 and 4 in chronic periodontitis

Chronic periodontitis is a common inflammatory disease initiated by a complex microbial biofilm and mediated by the host response causing destruction of the supporting tissues of the teeth. Host recognition of pathogens is mediated by toll-like receptors (TLRs) that bind conserved molecular patterns shared by large groups of microorganisms. The oral epithelial cells respond to most periodontopathic bacteria via TLR-2 and TLR-4. In addition to the membrane-associated receptors, soluble forms of TLR-2 (sTLR-2) and TLR-4 (sTLR-4) have been identified and are thought to play a regulatory role by binding microbial ligands. sTLR-2 has been shown to arise from ectodomain shedding of the extracellular domain of the membrane receptor and sTLR-4 is thought to be an alternate spliced form. Many studies have previously reported the presence of elevated numbers of viable exfoliated epithelial cells in the saliva of patients with chronic periodontitis. The objective of this study was to investigate the potential value of salivary sTLR-2 and sTLR-4 together with the paired epithelial cell-associated TLR-2/4 mRNA as diagnostic markers for chronic periodontitis. Unstimulated whole saliva was collected after obtaining informed consent from 40 individuals with either periodontitis or gingivitis. The sTLR-2 and sTLR4 in saliva was measured by enzyme-linked immunosorbent assay. The TLR-2 and TLR-4 transcript in the epithelial cells in saliva was measured by real time polymerase chain reaction. While levels of sTLR-2 exhibited an inverse correlation, sTLR-4 positively correlated with clinical parameters in the gingivitis cohort. Interestingly, both correlations were lost in the periodontitis cohort indicating a dysregulated host response. On the other hand, while the sTLR-2 and the paired epithelial cell associated TLR-2 mRNA exhibited a direct correlation (r2 = 0.62), that of sTLR4 and TLR-4 mRNA exhibited an inverse correlation (r2 = 0.53) in the periodontitis cohort. Collectively, assessments of salivary sTLR2 and sTLR4 together with the respective transcripts in the epithelial cells could provide clinically relevant markers of disease progression from gingivitis to periodontitis.

Effect of systemic long-term, low-dose aspirin on periodontal status and soluble CD14 in gingival crevicular fluid: a case-control study

AIM

In the present study, we evaluated the effect of systemic long-term, low-dose aspirin on the periodontal status and gingival crevicular fluid (GCF) concentrations of aspirin-triggered lipoxins (ATL) and soluble CD14 (sCD14).

METHODS

The study group consisted of 45 patients who were on long-term, low-dose aspirin therapy, and the control group included patients not on aspirin therapy. Mean bleeding index, plaque index (PI), probing depth (PD), and clinical attachment loss (CAL) were recorded. GCF samples were analyzed for concentrations of ATL, and sCD14 using enzyme-linked immunosorbent assay method.

RESULTS

The means of PI, PD, and CAL were higher for the control group compared to the study group. The mean concentration of ATL was significantly higher for the study group (49.13 ± 37.39 ng/mL). The mean concentration of sCD14 was higher in the control group (5.75 ± 3.91 μg/mL). There was a negative correlation in the study group between concentrations of ATL with PD (r = -0.54) and CAL (r = -0.123). There was a positive correlation between sCD14 and CAL (r = 0.047) in the study group. A negative correlation was also observed between concentrations of sCD14 and ATL (r = -0.134) in the study group.

CONCLUSION

The results indicate better periodontal status among long-term aspirin users compared to non-aspirin users.

Human periodontal ligament cells exhibit no endotoxin tolerance upon stimulation with Porphyromonas gingivalis lipopolysaccharide

Background/Objectives

Endotoxin tolerance is characterized by a state of hyporesponsiveness after confrontation with endotoxins such as lipopolysaccharides (LPS) at low concentrations. The aim of this study was to investigate, whether pretreatment with Porphyromonas gingivalis leads to endotoxin tolerance induction and possible alterations in toll‐like receptor (TLR) 2‐ and 4‐induced response in human periodontal ligament cells (hPDLCs).

Material and Methods

Primary hPDLCs were pretreated with P. gingivalis (0.1 or 0.3 μg/mL) LPS for 24 hours and afterwards treated with one of the following stimuli: P. gingivalis LPS (1 μg/mL); TLR4 agonist Escherichia coli LPS (0.1 μg/mL; 1 μg/mL); TLR2 agonist Pam3CSK4 (0.1 μg/mL; 1 μg/mL). The protein expression of interleukin (IL)‐6, IL‐8 and monocyte chemotactic protein‐1 was analyzed with quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay. Gene expression levels of TLR2 and TLR4 were determined by quantitative polymerase chain reaction.

Results

Pretreatment of cells with low concentrations of P. gingivalis LPS did not result in lower production of IL‐6, IL‐8 and monocyte chemotactic protein‐1 compared to control group. In some cases, pretreated cells exhibited lower gene expression levels of TLR2 and TLR4 compared to non‐pretreated cells.

Conclusion

The results of this study implicate that hPDLCs do not develop endotoxin tolerance. Furthermore, the amplitude of the inflammatory response shows no significant dependency on TLR2 and TLR4 expression levels.

Salivary sCD14 as a potential biomarker of dental caries activity in adults

CD14 is a co-receptor involved in the recognition of Gram-negative and Gram-positive bacteria, the latter known to cause dental caries. The aim of this study was to determine whether soluble CD14 (sCD14) in saliva was associated with caries activity and the collection method from the saliva. The study included 55 participants aged 20 to 40 years, 30 with dental caries and 25 caries-free controls. We collected 110 saliva samples in total, 55 of resting saliva and 55 of mechanically stimulated saliva. Median levels of sCD14, measured with a matrix-matched enzyme-linked immunosorbent assay (ELISA), were higher in the caries-active than in the caries-free group in either resting (203.3 vs.167.9 ng mL-1; P<0.01) or stimulated saliva (201 vs.105.7 ng mL-1; P<0.01). The resting salivary flow rate was lower in the caries-active than caries-free group (0.61±0.42 vs. 0.98±0.52 mL min-1; P<0.01). Hyposalivation was observed only in the caries-active group (10 and 13 % in stimulated and resting saliva, respectively). Higher salivary sCD14 levels and secretion rates were clearly associated with dental caries and resting saliva. Future studies should focus on the clinical utility of salivary sCD14 as a potential biomarker and predictor of future caries events.

Soluble CD14 Enhances the Response of Periodontal Ligament Stem Cells to P. gingivalis Lipopolysaccharide

Periodontal ligament stem cells (PDLSCs) are lacking membrane CD14, which is an important component of lipopolysaccharide (LPS) signaling through toll-like receptor (TLR) 4. In the present study we investigated the effect of soluble CD14 on the response of human PDLSCs to LPS of Porphyromonas (P.) gingivalis. Human PDLSCs (hPDLSCs) were stimulated with P. gingivalis LPS in the presence or in the absence of soluble CD14 (sCD14) and the production of interleukin (IL)-6, chemokine C-X-C motif ligand 8 (CXCL8), and chemokine C-C motif ligand 2 (CCL2) was measured. The response to P. gingivalis LPS was compared with that to TLR4 agonist Escherichia coli LPS and TLR2-agonist Pam3CSK4. The response of hPDLSCs to both P. gingivalis LPS and E. coli LPS was significantly enhanced by sCD14. In the absence of sCD14, no significant difference in the hPDLSCs response to two kinds of LPS was observed. These responses were significantly lower compared to that to Pam3CSK4. In the presence of sCD14, the response of hPdLSCs to P. gingivalis LPS was markedly higher than that to E. coli LPS and comparable with that to Pam3CSK4. The response of hPdLSCs to bacterial LPS is strongly augmented by sCD14. Local levels of sCD14 could be an important factor for modulation of the host response against periodontal pathogens.

Point-of-care diagnosis of periodontitis using saliva: technically feasible but still a challenge

Periodontitis is a chronic inflammation of the periodontium caused by persistent bacterial infection that leads to the breakdown of connective tissue and bone. Because the ability to reconstruct the periodontium is limited after alveolar bone loss, early diagnosis and intervention should be the primary goals of periodontal treatment. However, periodontitis often progresses without noticeable symptoms, and many patients do not seek professional dental care until the periodontal destruction progresses to the point of no return. Furthermore, the current diagnosis of periodontitis depends on time-consuming clinical measurements. Therefore, there is an unmet need for near-patient testing to diagnose periodontitis. Saliva is an optimal biological fluid to serve as a near-patient diagnostic tool for periodontitis. Recent developments in point-of-care (POC) testing indicate that a diagnostic test for periodontitis using saliva is now technically feasible. A number of promising salivary biomarkers associated with periodontitis have been reported. A panel of optimal biomarkers must be carefully selected based on the pathogenesis of periodontitis. The biggest hurdle for the POC diagnosis of periodontitis using saliva may be the process of validation in a large, diverse patient population. Therefore, we propose the organization of an International Consortium for Biomarkers of Periodontitis, which will gather efforts to identify, select, and validate salivary biomarkers for the diagnosis of periodontitis.

Association study between salivary levels of interferon (IFN)-gamma, interleukin (IL)-17, IL-21, and IL-22 with chronic periodontitis

OBJECTIVE

To investigate if the salivary levels of IL-17, IL-21, IL-22, and its ratio regarding salivary IFN-γ may be linked with the periodontal clinical status.

DESIGN

One hundred and five chronic periodontitis (CP) subjects and 44 healthy controls (HC) were recruited. Periodontal status was assessed based on full-mouth clinical periodontal measurements. Cytokine salivary levels were analyzed by ELISA. The association between the analytes with CP was analyzed using a binary logistic regression model.

RESULTS

A statistically significant increase in salivary levels of IFN-γ and IFN-γ/IL-22 ratio in CP group could be detected, but there was no significant domination of any Th17 cytokine that could be of predictive value for health/disease status. Univariate and binary logistic regression analyses revealed a strong and independent association of IFN-γ salivary levels and IFN-γ/IL-22 ratio with disease status. An interaction effect of ageing on IFN-γ levels also could be noted.

CONCLUSION

While salivary levels of IFN-γ and IFN-γ/IL-22 ratio may act as strong/independent indicators of the amount and extent of periodontal breakdown, the low detection frequency of Th17 cytokines in saliva samples make these determinations useless for the detection of disease presence and/or its severity.

Soluble toll like receptor 2 (TLR-2) is increased in saliva of children with dental caries

Background

Dental caries is the most common microbial disease affecting mankind. Caries risk assessment methods, identification of biomarkers and vaccine development strategies are being emphasized to control the incidence of the largely preventable disease. Pattern recognition receptors such as the toll like receptors (TLR) have been implicated as modulators of host-microbial interactions. Soluble TLR-2 and its co-receptor, CD14 identified in saliva can bind the cell wall components of cariogenic bacteria and modulate the disease process. The objective of this study is to determine the potential of salivary sTLR-2 and sCD14 as biomarkers of caries activity and indirect measures of the cariogenic bacterial burden.

Methods

Unstimulated whole saliva was collected from twenty caries free and twenty caries active children between the ages of 5 and 13 years. The concentration of sCD14 and sTLR-2 together with that of the cytokine IL-8 reported to be increased in dental caries was assessed by the enzyme linked immunosorbent assay.

Results

While the level of sCD14 and that of IL-8 was equivocal between the two groups, the sTLR-2 concentration in caries active saliva was significantly higher than that in caries free saliva.

Conclusions

The sTLR-2 in saliva could serve as a potential biomarker for caries activity.

Protein biomarkers of periodontitis in saliva

Periodontitis is a chronic inflammatory condition of the tissues that surround and support the teeth and is initiated by inappropriate and excessive immune responses to bacteria in subgingival dental plaque leading to loss of the integrity of the periodontium, compromised tooth function, and eventually tooth loss. Periodontitis is an economically important disease as it is time-consuming and expensive to treat. Periodontitis has a worldwide prevalence of 5-15% and the prevalence of severe disease in western populations has increased in recent decades. Furthermore, periodontitis is more common in smokers, in obesity, in people with diabetes, and in heart disease patients although the pathogenic processes underpinning these links are, as yet, poorly understood. Diagnosis and monitoring of periodontitis rely on traditional clinical examinations which are inadequate to predict patient susceptibility, disease activity, and response to treatment. Studies of the immunopathogenesis of periodontitis and analysis of mediators in saliva have allowed the identification of many potentially useful biomarkers. Convenient measurement of these biomarkers using chairside analytical devices could form the basis for diagnostic tests which will aid the clinician and the patient in periodontitis management; this review will summarise this field and will identify the experimental, technical, and clinical issues that remain to be addressed before such tests can be implemented.

Evaluation of salivary biomarker profiles following non-surgical management of chronic periodontitis

OBJECTIVES

Soluble toll-like receptor-2 (sTLR-2) and cytokines in saliva were assessed as clinical markers for chronic periodontitis in a longitudinal study.

MATERIALS AND METHODS

Unstimulated whole saliva was collected from 20 periodontally healthy individuals and 20 patients with chronic periodontitis at diagnosis and at 1 and 6 weeks following scaling and root planing (SRP). Biomarkers including the cytokines (IL-4, IL-6, IL-10, and IL-17), sTLR-2, and sCD14 in saliva were measured by enzyme-linked immunosorbent assay. Mann-Whitney U-test and Student's t-test were used to determine the significance between healthy and chronic periodontitis groups and that between pre- and post-SRP samples, respectively.

RESULTS

Salivary sTLR-2, IL-17, and IL-10 levels were significantly lower and those of sCD14, IL-6, and IL-4 were significantly higher in patients with chronic periodontitis as compared with healthy controls. Furthermore, sTLR-2 and IL-4 in saliva reached levels comparable to those of healthy individuals at 6-week re-evaluation visit, implicating a correlation of the two markers with the disease process.

CONCLUSIONS

Our data suggest that salivary sTLR-2 is a potential prognostic or maintenance marker for chronic periodontitis. The observed variability of salivary cytokines is consistent with the role of these cytokines in the progression of chronic periodontitis.

Soluble CD14 induces cytokine release by human oral epithelial cells

BACKGROUND AND OBJECTIVE

The epithelial cell barrier is the first line of host defense against bacterial aggression in periodontal sites. In view of the fact that oral epithelial cells do not express membrane CD14 and that high levels of the soluble form of the CD14 receptor have been detected in the gingival crevicular fluid of patients with periodontitis, we investigated the effects of recombinant soluble CD14 (rsCD14), alone and in combination with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) on the inflammatory response of human oral epithelial cells.

MATERIAL AND METHODS

The oral epithelial cell line GMSM-K was stimulated with rsCD14, alone or in combination with A. actinomycetemcomitans LPS, and the levels of the inflammatory mediators interleukin (IL)-6, IL-8 and chemokine (C-C motif) ligand 5 (CCL5) were determined using ELISAs. Activation of the transcription factors nuclear factor-κB (NF-κB) and activator protein-1 was also monitored using ELISAs.

RESULTS

rsCD14 significantly induced the secretion of IL-6, IL-8 and CCL5 by oral epithelial cells. The combination of rsCD14 and A. actinomycetemcomitans LPS augmented this effect. Activation of the NF-κB pathway was significantly increased in epithelial cells treated with rsCD14 compared with a nonstimulated control, whereas there was no effect on the activation of activator protein-1.

CONCLUSION

rsCD14 stimulated the inflammation cascade in oral epithelial cells, both alone or when associated with bacterial LPS, through an NF-κB-dependent pathway. This suggests that the presence of soluble CD14 in periodontitis lesions may contribute to the inflammatory process of periodontal disease.

Serum sCD14, polymorphism of CD14(-260) and periodontal infection

BACKGROUND AND AIMS

CD14 is a co-receptor involved in the recognition of Gram-negative and positive bacteria. Infections are known to influence serum sCD14 levels, and CD14 gene promoter polymorphism (CD14 C-260T) has been reported to be associated with many infectious diseases. Our aim was to investigate whether serum sCD14 concentration is associated with periodontal infection and the CD14(-260) genotype.

SUBJECTS AND METHODS

The periodontal status of 56 subjects with chronic periodontitis and 28 controls was clinically examined. Serum sCD14 concentration was analyzed using ELISA and CD14(-260) genotype using polymerase chain reaction (PCR).

RESULTS

The mean concentration of sCD14 in serum was significantly higher in subjects with periodontitis than in control subjects (4.9 microg ml(-1)vs 3.8 microg ml(-1), P < 0.001). Serum sCD14 concentration associated significantly with the extent of advanced periodontal disease. In a regression analysis including both subject groups, the CD14(-260) genotype was a significant determinant for serum sCD14 concentration. After stratification by periodontal health status (periodontitis vs controls), the influence of the CD14(-260) genotype on serum sCD14 concentration was seen only in the control group.

CONCLUSIONS

Periodontal infection is associated with the serum concentration of sCD14. Moderate to severe periodontal infection overshadows the influence of the genotype on serum sCD14 concentration.