Oral Antimicrobial Peptides and Biological Control of Caries

The presence of antimicrobial peptides (AMPs) in saliva may be a biological factor that contributes to susceptibility or resistance to caries. This manuscript will review AMPs in saliva, consider their antimicrobial and immunomodulatory functions, and evaluate their potential role in the oral cavity for protection of the tooth surface as well as the oral mucosa. These AMPs are made in salivary gland and duct cells and have broad antimicrobial activity. Alpha-defensins and LL37 are also released by neutrophils into the gingival crevicular fluid. Both sources may account for their presence in saliva. A recent study in middle school children aimed to determine a possible correlation between caries prevalence in children and salivary concentrations of the antimicrobial peptides human beta-defensin-3 (hBD-3), the cathelicidin, LL37, and the alpha-defensins. The levels of these AMPs were highly variable in the population. While levels of LL37 and hBD-3 did not correlate with caries experience, the mean alpha-defensin level was significantly higher in children with no caries than in children with caries (p < 0.005). We conclude that several types of AMPs that may have a role in oral health are present in unstimulated saliva. Low salivary levels of alpha-defensin may represent a biological factor that contributes to caries susceptibility. Our observation could lead to new ways to prevent caries and to a new tool for caries risk assessment

Dynamic changes of Th1/Th2/Th17 cytokines and hBD-2/3 in erosive oral lichen planus patients saliva before and after prednisone acetate treatment

Objective: This study aimed to investigate the expression of T helper 1 (Th1)/Th2/Th17- related cytokines and human beta defensins 2 and 3 (hBD-2 and -3) in the saliva of patients with erosive oral lichen planus (EOLP) and to explore their role in the pathogenesis of EOLP and the effects of glucocorticoids on EOLP. Methods: A total of 30 patients with EOLP and 20 age- and sex-matched healthy individuals were included in this study. The patients were treated with prednisone at a dose of 0.4 mg/(kg·d) for 1 week and examined before and after treatment. Unstimulated whole saliva samples were collected to determine the levels of cytokines (interleukin 1 beta [IL-1β], tumour necrosis factor alpha [TNF]-α, interferon gamma [IFN-γ], IL-4, IL-6, IL-10 and IL-17) by cytometric bead array and those of hBD-2 and -3 b y enzyme-linked immunosorbent assay. In addition, oral rinse samples were collected to detect Candida load. Results: The levels of salivary IL-1β, IL-6, hBD-2 and hBD-3 were higher and the IFN-γ/IL-4 and IL-1β/IL-6 ratios were lower in patients with EOLP than in healthy individuals. In patients with EOLP, hBD-2 levels were positively correlated with IFN-γ levels and negatively correlated with IL-17 levels, whereas hBD-3 levels were negatively correlated with IL-17 and IL-10 levels. In addition, the prevalence of EOLP was positively correlated with IL-6 levels and negatively correlated with the IFN-γ/IL-4 ratio. The levels of IL-1β, TNF-α, IFN-γ, IL-6, hBD-2 and hBD-3 and the IFN-γ/IL-4 ratio decreased after treatment with prednisone for 1 week. The levels of IL-6, hBD-2 and hBD-3 were significantly higher in EOLP patients than in healthy individuals; while TNF-α levels and the IFN-γ/IL-4 ratio were significantly lower in EOLP patients than in healthy individuals. Furthermore, the oral counts of Candida spp. (colony forming unit [CFU]) were negatively correlated with TNF-α levels. Numerical Rating Scale(NRS) and Sign scores decreased in EOLP patients after treatment. Approximately 80 % of patients were effectively treated. Salivary TNF-α levels were significantly higher in the treatment-ineffective group than in the treatment-effective group before treatment with prednisone, and differences in salivary IL-6 levels before and after treatment were significantly higher in the treatment-effective group than in the treatment-ineffective group. Conclusions: High expression of IL-1β, IL-6, hBD-2 and Th1/Th2 imbalance in saliva may be associated with the pathogenesis of EOLP. IFN-γ/IL-4 balance may serve as a protective factor for EOLP. Glucocorticoids significantly alleviate the symptoms of EOLP and inhibit the expression of Th1/Th2 cytokines

Sensitivity analysis of histological HCV recurrence.

<p>Sensitivity analysis of histological HCV recurrence.</p

Diagram indicating the presence of antimicrobial peptides in saliva (blue), in gingival epithelium (pink), and in neutrophils (PMNs) migrating into the oral cavity via the gingival crevicular fluid

<p><b>Copyright information:</b></p><p>Taken from "Oral Antimicrobial Peptides and Biological Control of Caries"</p><p>BMC Oral Health 2006;6(Suppl 1):S13-S13.</p><p>Published online 15 Jun 2006</p><p>PMCID:PMC2147588.</p><p></p> All of these sources of antimicrobial peptides may aid protection of the mucosa from bacterial infection and the tooth surface from caries

Forest plot of graft loss due to HCV recurrence comparing tacrolimus-based to cyclosporine-based group.

<p>Forest plot of graft loss due to HCV recurrence comparing tacrolimus-based to cyclosporine-based group.</p

Forest plot of retransplantation due to HCV recurrence comparing tacrolimus-based to cyclosporine-based group.

<p>Forest plot of retransplantation due to HCV recurrence comparing tacrolimus-based to cyclosporine-based group.</p

Tacrolimus-Based versus Cyclosporine-Based Immunosuppression in Hepatitis C Virus-Infected Patients after Liver Transplantation: A Meta-Analysis and Systematic Review

<div><p>Background</p><p>Most liver transplant recipients receive calcineurin inhibitors (CNIs), especially tacrolimus and cyclosporine, as immunosuppressant agents to prevent rejection. A controversy exists as to whether the outcomes of hepatitis C virus (HCV)-infected liver transplant patients differ based on the CNIs used. This meta-analysis compares the clinical outcomes of tacrolimus-based and cyclosporine-based immunosuppression, especially cases of HCV recurrence in liver transplant patients with end-stage liver disease caused by HCV infection.</p><p>Methods</p><p>Related articles were identified from the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, Medline, and Embase. Meta-analyses were performed for the results of homogeneous studies.</p><p>Results</p><p>Nine randomized or quasi-randomized controlled trials were included. The total effect size of mortality (RR = 0.98, 95% CI: 0.77–1.25, <i>P</i> = 0.87) and graft loss (RR = 1.05, 95% CI: 0.83–1.33, <i>P</i> = 0.67) showed no significant difference between the two groups irrespective of duration of immunosuppressant therapy after liver transplantation. In addition, the HCV recurrence-induced mortality (RR = 1.11, 95% CI: 0.66–1.89, <i>P</i> = 0.69), graft loss (RR = 1.62, 95% CI: 0.64–4.07, <i>P</i>  = 0.31) and retransplantation (RR = 1.40, 95% CI: 0.48–4.09, <i>P</i> = 0.54), as well as available biopsies, confirmed that histological HCV recurrences (RR =  0.92, 95% CI: 0.71–1.19, <i>P</i> = 0.51) were similar.</p><p>Conclusion</p><p>These results suggested no difference in posttransplant HCV recurrence-induced mortality, graft loss and retransplantation, as well as histological HCV recurrence in patients treated with tacrolimus-based and cyclosporine-based immunosuppresion.</p></div

Forest plot of graft loss comparing tacrolimus-based to cyclosporine-based group.

<p>Forest plot of graft loss comparing tacrolimus-based to cyclosporine-based group.</p

Characteristics of randomized and quasi-randomized trials included in the systematic review.

<p>NS = not stated.</p><p>MMF = mycophenolate mofetil; AZA = azathioprine.</p><p>Characteristics of randomized and quasi-randomized trials included in the systematic review.</p