Anti-inflammatory cytokine IL-10 and T cell cytokine profile in periodontitis granulation tissue

Periodontal granulation tissue - To remove or not to remove, that is the question

Formation of granulation tissue is a fundamental phase in periodontal wound healing with subsequent maturation leading to regeneration or repair. However, persistently inflamed granulation tissue presents in osseous defects as a result of periodontitis and is routinely disrupted and discarded with non-surgical and surgical therapy to facilitate wound healing or improve chances of regeneration. Histological assessment suggests that granulation tissue from periodontitis-affected sites is effectively a chronic inflammatory tissue resulting from impaired wound healing due to persistence of bacterial dysbiotic bioflim. Nevertheless, the immunomodulatory potential and stem cell characteristics in granulation tissue have also raised speculation about the tissue's regenerative potential. This has led to the conception and recent implementation of surgical techniques which preserve granulation tissue with the intention of enhancing innate regenerative potential and improve clinical outcomes. As knowledge of fundamental cellular and molecular functions regulating periodontitis-affected granulation tissue is still scarce, this review aimed to provide a summary of current understanding of granulation tissue in the context of periodontal wound healing. This may provide new insights into clinical practice related to the management of granulation tissue and stimulate further investigation.

The role of acquired host immunity in periodontal diseases

The aim of this narrative review is to relate the contribution of European researchers to the complex topic of the host immune system in periodontal disease, focusing on acquired immunity. Other chapters in this volume will address the genetics and autoantibody responses and other forms of immunity to periodontal disease. While the contribution of European authors is the focus, global literature is included in this descriptive narrative for contextual clarity, albeit many with European co-authors. The topic is relatively intense and is thus broken down into sections outlined below, tackled as descriptive narratives to enhance understanding. Any attempt at a systematic or scoping review was quickly abandoned given the descriptive nature and marked variation of approach in almost all publications. Even the most uniform area of this acquired periodontal immunology literature, antibody responses to putative pathogens in periodontal diseases, falls short of common structures and common primary outcome variables one would need and expect in clinical studies, where randomized controlled clinical trials (RCTs) abound. Addressing 'the host's role' in immunity immediately requires a discussion of host susceptibility, which necessitates consideration of genetic studies (covered elsewhere in the volume and superficially covered here).

Th-Cell Subsets of Submandibular Lymph Nodes in Peri-Implantitis

BACKGROUND

Implant surgery is a popular operation in craniomaxillofacial surgery, but the occurrence of peri-implantitis affects the success and survival rate of the implant. Research has found that Th-cell-related cytokines are associated with peri-implantitis. However, the distribution and proportions of Th-cell subsets in submandibular lymph nodes' immune environments during the progression of peri-implantitis remain unclear.

METHODS

Forty-eight rats were randomly divided into 4 groups: the control group, the 1-week ligation peri-implantitis induction (Lig 1w) group, the Lig 2w group, and the Lig 4w group (n=12). Ligation was maintained for different times to induce peri-implantitis 4 weeks after implantation. Inflammation and bone resorption were examined by clinical probing and micro-CT. The submandibular lymph nodes were harvested for quantitative real-time polymerase chain reaction and flow cytometry to obtain the Th-cell profiles.

RESULTS

With increasing ligation time, more redness and swelling in the gingiva and more bone resorption around the implant were observed (P<0.05). The proportions of Th1 and Th17 cells increased, the proportion of Th2 cells decreased, and the proportion of Treg cells first increased and then decreased in the lymph nodes (P<0.05).

CONCLUSIONS

This study provided a preliminary characterization of the temporal distribution of Th cells in lymph nodes of peri-implantitis. Persistent elevation of Th1 and Th17 proportions and decrease of Treg proportion may be the cause of bone resorption in peri-implantitis. Lymphatic drainage may be a bridge between craniomaxillofacial diseases and systemic diseases. Early immune support against T cells may be a potential therapeutic idea for the prevention of implant failure and the potential risk of systemic disease.

Immune dysregulation and macrophage polarization in peri-implantitis

The term "peri-implantitis" (peri-implantitis) refers to an inflammatory lesion of the mucosa surrounding an endosseous implant and a progressive loss of the peri-implant bone that supports the implant. Recently, it has been suggested that the increased sensitivity of implants to infection and the quick elimination of supporting tissue after infection may be caused by a dysregulated peri-implant mucosal immune response. Macrophages are polarized in response to environmental signals and play multiple roles in peri-implantitis. In peri-implantitis lesion samples, recent investigations have discovered a considerable increase in M1 type macrophages, with M1 type macrophages contributing to the pro-inflammatory response brought on by bacteria, whereas M2 type macrophages contribute to inflammation remission and tissue repair. In an effort to better understand the pathogenesis of peri-implantitis and suggest potential immunomodulatory treatments for peri-implantitis in the direction of macrophage polarization patterns, this review summarizes the research findings related to macrophage polarization in peri-implantitis and compares them with periodontitis.

Nociceptor-Macrophage Interactions in Apical Periodontitis: How Biomolecules Link Inflammation with Pain

Periradicular tissues have a rich supply of peripheral afferent neurons, also known as nociceptive neurons, originating from the trigeminal nerve. While their primary function is to relay pain signals to the brain, these are known to be involved in modulating innate and adaptive immunity by initiating neurogenic inflammation (NI). Studies have investigated neuroanatomy and measured the levels of biomolecules such as cytokines and neuropeptides in human saliva, gingival crevicular fluid, or blood/serum samples in apical periodontitis (AP) to validate the possible role of trigeminal nociceptors in inflammation and tissue regeneration. However, the contributions of nociceptors and the mechanisms involved in the neuro-immune interactions in AP are not fully understood. This narrative review addresses the complex biomolecular interactions of trigeminal nociceptors with macrophages, the effector cells of the innate immune system, in the clinical manifestations of AP.

Relationship between soluble neuropilin-1 in the gingival crevicular fluid of early pregnant women and different severities of periodontitis: A cross-sectional study

Background

Pregnancy exacerbates the periodontal inflammation; however, the biological mediators involved are not well characterized. Neuropilins (NRPs) are transmembrane glycoproteins involved in physiological and pathogenic processes such as angiogenesis and immunity but its relationship with periodontal disease in pregnant women has not been studied.

Objective

To explore the soluble Neuropilin-1 (sNRP-1) levels in gingival crevicular fluid (GCF) samples during early pregnancy and its association with the periodontitis severity and periodontal clinical parameters.

Methods

80 pregnant women were recruited, and GCF samples were collected. Clinical data and periodontal clinical parameters were recorded. sNRP-1 expression was determined by ELISA assay. The relationship between sNRP-1(+) pregnant women with the severity of periodontitis and periodontal clinical parameters was determined by Kruskal-Wallis and Mann-Whitney tests. Spearman's test estimated the correlation between sNRP-1 levels and periodontal clinical parameters.

Results

Periodontitis was classified as mild in 27.5% (n = 22) women, moderate in 42.5% (n = 34), and severe in 30% (n = 24). sNRP-1 expression was higher in the GCF of pregnant with severe (41.67%) and moderate (41.17%) periodontitis compared than in those with mild periodontitis (18.8%). The sNRP-1(+) pregnant had a higher BOP (76.5% v/s 57%; p = 0.0071) and PISA (1199.5 mm2 v/s 880.2 mm2; p = 0.0282) compared with sNRP-1(-). A positive correlation between sNRP-1 levels in GCF and BOP (p = 0.0081) and PISA (p = 0.0398) was observed.

Conclusions

The results suggest that sNRP-1 could be involved in periodontal inflammation during pregnancy.

In vitro and in vivo study of the pathogenic role of PPARα in experimental periodontitis

OBJECTIVE

The purpose of this study is to investigate the pathogenic role of PPARα in periodontal antigen treated gingival cells in vitro and in experimental periodontitis in vivo .

METHODOLOGY

Gingival fibroblasts, gingival epithelial cells and splenocytes were isolated from C57BL/6J wild type (WT) mice and treated with fixed P. gingivalis at for 48 hours. The mRNA levels of PPARs, TNFα, IL-1β and IL-10 were detected by Real-time quantitative PCR. Silk ligatures after being soaked in the P.gingivalis suspension were tied around both maxillary second molars of WT mice or PPARα knock-out (KO) mice for two weeks. PPARα agonist fenofibrate and vehicle control were injected into the different side of the palatal gingiva on days 3, 6, and 9. At day 14, bone resorption and gingival mRNA expression levels of PPARs, TNFα, IL-1β and IL-10 were measured by micro-computed tomography and RT-qPCR respectively.

RESULTS

P. gingivalis treatment downregulated the expression of PPARα, but not PPARβ or PPARγ, and increased the expression of TNF-α and IL-1β in Gingival fibroblasts, gingival epithelial cells and splenocytes from WT mice. Gingival mRNA levels of PPARα were significantly decreased in experimental periodontitis in WT mice. The bone loss of PPARα KO mice in experimental periodontitis was significantly higher than WT mice and was not reduced by fenofibrate treatment. Gingival TNFα protein expressions were significantly increased by P. gingivalis associated ligation and decreased by fenofibrate treatment in WT mice but not in PPARα KO mice.

CONCLUSION

This study suggests that PPARα plays an essential role in periodontitis.

Cellular Mechanisms of Inflammaging and Periodontal Disease

Increased age is associated with an increased prevalence of chronic inflammatory diseases and conditions. The term inflammaging has been used to describe the age-related changes to the immune response that results in a chronic and elevated inflammatory state that contributes, in part, to the increased prevalence of disease in older adults. Periodontal disease is a chronic inflammatory condition that affects the periodontium and increases in prevalence with age. To better understand the mechanisms that drive inflammaging, a broad body of research has focused on the pathological age-related changes to key cellular regulators of the immune response. This review will focus on our current understanding of how certain immune cells (neutrophils, macrophages, T cells) change with age and how such changes contribute to inflammaging and more specifically to periodontal disease.

Current status, and the developments of hosts and expression systems for the production of recombinant human cytokines

Cytokines consist of peptides, proteins and glycoproteins, which are biological signaling molecules, and boost cell-cell communication in immune reactions to stimulate cellular movements in the place of trauma, inflammation and infection. Recombinant cytokines are designed in such a way that they have generalized immunostimulation action or stimulate specific immune cells when the body encounters immunosuppressive signals from exogenous pathogens or other tumor microenvironments. Recombinant cytokines have improved the treatment processes for numerous diseases. They are also beneficial against novel toxicities that arise due to pharmacologic immunostimulators that lead to an imbalance in the regulation of cytokine. So, the production and use of recombinant human cytokines as therapeutic proteins are significant for medical treatment purposes. For the improved production of recombinant human cytokines, the development of host cells such as bacteria, yeast, fungi, insect, mammal and transgenic plants, and the specific expression systems for individual hosts is necessary. The recent advancements in the field of genetic engineering are beneficial for easy and efficient genetic manipulations for hosts as well as expression cassettes. The use of metabolic engineering and systems biology approaches have tremendous applications in recombinant protein production by generating mathematical models, and analyzing complex biological networks and metabolic pathways via simulations to understand the interconnections between metabolites and genetic behaviors. Further, the bioprocess developments and the optimization of cell culture conditions would enhance recombinant cytokines productivity on large scales.

Frailty, aging, and periodontal disease: Basic biologic considerations

Aging is associated with the development of disease. Periodontal disease is one of the many diseases and conditions that increase in prevalence with age. In addition to the traditional focus on individual age-related conditions, there is now a greater recognition that multisystem conditions such as frailty play an important role in the health of older populations. Frailty is a clinical condition in older adults that increases the risk of adverse health outcomes. Both frailty and periodontal disease are common chronic conditions in older populations and share several risk factors. There is likely a bidirectional relationship between periodontal disease and frailty. Comorbid systemic diseases, poor physical functioning, and limited ability to self-care in frail older people have been implicated as underlying the association between frailty and periodontal disease. In addition, both frailty and periodontal disease also have strong associations with inflammatory dysregulation and other age-related pathophysiologic changes that may similarly underlie their development and progression. Investigating age-related changes in immune cells that regulate inflammation may lead to a better understanding of age-related disease and could lead to therapeutic targets for the improved management of frailty and periodontal disease.

The Contribution of Macrophages in Old Mice to Periodontal Disease

The prevalence of periodontal disease increases with age. Systemic inflammatory dysregulation also increases with age and has been reported to contribute to the myriad of diseases and conditions that become more prevalent with advanced age. As periodontal disease involves a dysregulated host inflammatory response, the age-related inflammatory dysregulation may contribute to the pathogenesis of periodontal disease in aging populations. However, our understanding of what drives the age-related inflammatory dysregulation is limited. Here, we investigate the macrophage and its contribution to periodontal disease in old and young mice using a ligature-induced periodontal disease model. We demonstrate that control old mice present with an aged periodontal phenotype, characterized by increased alveolar bone loss and increased local inflammatory cytokine expression compared to young mice. Macrophages were demonstrated to be present in the periodontium of old and young mice in equal numbers in controls, during disease induction, and during disease recovery. However, it appears age may have a detrimental effect on macrophage activity during disease recovery. Depletion of macrophages during disease recovery in old mice resulted in decreased inflammatory cytokines within the gingiva and decreased bone loss as measured by micro-computed tomography. In young mice, macrophage depletion during disease recovery had no beneficial or detrimental effect. Macrophage depletion during disease induction resulted in decreased disease severity similarly in young and old mice. Findings from this work support the diverse roles of macrophages in disease induction as well as the active roles of disease recovery, including the resolution of inflammation. Here, we conclude that age-related changes to the macrophage appear to be detrimental to the recovery from disease and may explain, in part, the age-related increase in prevalence of periodontal disease. Future studies examining the specific intrinsic age-related changes to the macrophage will help identify therapeutic targets.

Effect of Psoralen on the Intestinal Barrier and Alveolar Bone Loss in Rats With Chronic Periodontitis

To study the effects of psoralen on the intestinal barrier and alveolar bone loss (ABL) in rats with chronic periodontitis. Fifty-two 8-week-old specific pathogen-free (SPF) male Sprague-Dawley (SD) rats were randomly divided into the following four groups: Control group (Control), psoralen group of healthy rats (Pso), periodontitis model group (Model), and psoralen group of periodontitis rats (Peri+Pso). The alveolar bone resorption of maxillary molars was observed via haematoxylin-eosin staining and micro-computed tomography. The expression level of receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in periodontal tissues was evaluated by immunofluorescence staining. The changes in serum tumour necrosis factor (TNF)-α, interleukin (IL)-10, IL-6, intestinal mucosal occludin, and claudin-5 were detected using enzyme-linked immunosorbent assay (ELISA). The level of intestinal mucosal NOD2 was detected using immunohistochemical methods. DNA was extracted from the intestinal contents and the 16s rRNA gene was sequenced using an Illumina MiSeq platform. The expression of NOD2 protein in the intestinal tract of periodontitis rats decreased after intragastric psoralen administration. Psoralen increased the intestinal microbiota diversity of rats. The level of serum pro-inflammatory factor TNF-α decreased and the level of anti-inflammatory factor IL-10 increased. ABL was observed to be significantly decreased in rats treated with psoralen. Psoralen decreased the RANKL/OPG ratio of periodontitis rats. Psoralen may affect the intestinal immune barrier and ecological barrier, mediate immune response, promote the secretion of anti-inflammatory factor IL-10, and reduce the secretion of the pro-inflammatory factor TNF-α, thus reducing ABL in experimental periodontitis in rats.

Maintaining homeostatic control of periodontal bone tissue

Alveolar bone is a unique osseous tissue due to the proximity of dental plaque biofilms. Periodontal health and homeostasis are mediated by a balanced host immune response to these polymicrobial biofilms. Dysbiotic shifts within dental plaque biofilms can drive a proinflammatory immune response state in the periodontal epithelial and gingival connective tissues, which leads to paracrine signaling to subjacent bone cells. Sustained chronic periodontal inflammation disrupts "coupled" osteoclast-osteoblast actions, which ultimately result in alveolar bone destruction. This chapter will provide an overview of alveolar bone physiology and will highlight why the oral microbiota is a critical regulator of alveolar bone remodeling. The ecology of dental plaque biofilms will be discussed in the context that periodontitis is a polymicrobial disruption of host homeostasis. The pathogenesis of periodontal bone loss will be explained from both a historical and current perspective, providing the opportunity to revisit the role of fibrosis in alveolar bone destruction. Periodontal immune cell interactions with bone cells will be reviewed based on our current understanding of osteoimmunological mechanisms influencing alveolar bone remodeling. Lastly, probiotic and prebiotic interventions in the oral microbiota will be evaluated as potential noninvasive therapies to support alveolar bone homeostasis and prevent periodontal bone loss.

Novel composite trachea grafts using 3-dimensional printing

Objective

Porcine-derived small intestine submucosa (SIS) extracellular matrix (ECM) surgical patches claim to have greater regenerative properties compared with dermal extracellular matrices. We hypothesized that using SIS-ECM in a bioengineered composite tracheal graft would allow better incorporation into the native tissue.

Methods

Two types of size-matched polycaprolactone support scaffolds were designed: rigid and flexible. The SIS-ECM was wrapped around the polycaprolactone supports lining the inside and outside of the graft. The grafts were implanted in 4 Yorkshire pigs, replacing an ∼2 cm segment of native trachea. Airway patency was evaluated with computed tomography scans and explanted grafts were examined grossly and histologically.

Results

All animals survived through the immediate postoperative period. Generally, extraluminal examination showed a smooth transition between native and graft without significant volumetric loss. Animals that received the flexible design survived ∼10 days longer than those that received the rigid design; however, severe perianastomotic intraluminal granulation tissue was observed. The rigid design had less significant intraluminal granulation tissue development at the distal anastomosis, but partial dehiscence had occurred at the proximal anastomosis interrupting graft incorporation.

Conclusions

The generally good extraluminal graft incorporation in our composite tracheal graft highlights some increased regenerative capabilities of SIS-ECM. However, the presence of intraluminal granulation tissue indicates that its use as an off-the-shelf, unaltered substrate in an airway graft is still not ideal. Further research must be conducted to determine whether a modification of the substrate is possible to enhance luminal airway incorporation and to exert control over the mechanisms responsible for granulation tissue development.

Proinflammatory cytokine polarization in type 2 diabetes

Subclinical inflammatory reaction is associated with non-insulin dependent diabetes. Therefore, the aim of the present study is to describe the effect of the three cytokines: interferon γ (IFN-γ), interleukin (IL)-4 and IL-5 on the development of type 2 diabetes (T2D). Forty-five volunteers (after their permission) were participated in this work; according to their clinical examination and laboratory investigations (fasting blood sugar, 2 hours postprandial, HbA1c and lipid profile), they were divided into thirteen control (non-diabetic) (five females and eight males) and thirty-two diabetic patients (twenty-one females and eleven males). Thereafter, their sera were evaluated for C-reactive protein (CRP), IFN-γ, IL-4 and IL-5. The results revealed an increasing trend of CRP and a significant increase of IFN-γ in diabetic patients with no sex difference. A positive correlation between IFN-γ and both IL-4 and IL-5 in control, and a positive correlation between IL-4 and IL-5 in diabetic patients had been visualized. These results denoted that there may be an association of the pro-inflammatory cytokines in the etiology of diabetes mellitus type 2.

Salivary immunoglobulins (A, G, and M) in type 1 diabetes mellitus patients: A PROSPERO-registered systematic review and meta-analysis

OBJECTIVE

To assess the difference in the salivary levels of immunoglobulins between patients with type 1 diabetes mellitus (DM1) and healthy controls.

DESIGN

This systematic review was registered on the PROSPERO (CRD42020159198) database. All references were cross-checked and the risk of bias assessment was conducted using the Newcastle-Ottawa Scale. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to appraise the quality of evidence. The standardized mean difference and Cohen's d as the effect size were used in the meta-analysis. I-square statistics was used to estimate heterogeneity. Analysis was performed using the RevMan® software (p < 0.05) with a 95 % confidence interval.

RESULTS

Of the total 92 articles, 9 were selected for this study. The meta-analysis included 333 DM1 patients and 325 healthy controls. DM1 patients showed a significant reduction in salivary flow (p = 0.0008; Cohen's d= -0.19, CI 95 %= -0.33, -0.05), although not significant enough to modify the IgA concentration (p = 0.120; Cohen's d = 0.58, CI 95 %= -0.15, 1.32). However, DM1 increased IgA concentration by reducing salivary flow (Cohen's d = 0.84; CI 95 % = 0.36, 1.32), with a strong estimate of effect (p = 0.0006). Regarding IgG, no significant change was noted with DM1 in the patient's saliva (p = 0.420). Furthermore, there was no significant variation in the salivary IgM levels (p = 0.300).

CONCLUSIONS

The data suggest that the salivary levels of the evaluated immunoglobulins do not seem to be altered in DM1 patients when compared to that in healthy controls. However, the increase in IgA salivary concentration was dependent on total protein estimation.

A review of T helper 17 cell-related cytokines in serum and saliva in periodontitis

Periodontitis is a chronic inflammatory disease with a complex underlying immunopathology. Cytokines, as molecular mediators of inflammation, play a role in all stages of disease progression. T helper 17 (Th17) cells are thought to play a role in periodontitis. Th17 cell development and maintenance requires a pro-inflammatory cytokine milieu, with many of the cytokines implicated in the pathogenesis of periodontitis. Serum and saliva are easily accessible biofluids which can represent the systemic and local environment to promote the development of Th17 cells. Here we review human clinical studies that investigate IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in serum and saliva in periodontitis. We highlight their putative role in the pathogenesis of periodontitis and place them within a wider context of animal and other clinical studies.

Estimation of Sialic Acid and IL10 Levels in Stage 1 and 2 Periodontitis Patients

Objective

The role of biomarkers in staging and grading periodontal disease has become detrimental in relation to the overall treatment plan. This study aimed at evaluating and comparing the role of sialic acid and IL10 in the early and moderate stages of periodontitis.

Materials and Methods

Patients were selected according to the assessment of pocket depth and radiographic bone loss. Bone loss was calculated as <15% for stage 1 and 15–33% for stage 2. Salivary samples were collected using spit technique 2 hrs post consumption of food. The unstimulated saliva was collected in a sterile graduated container every minute for 5–8 minutes. IL10 estimation was done using ELISA, and sialic acid estimation was done using the diphenylamine method. The variables for the three groups were assessed using ANOVA, and intragroup comparisons for quantitative data were evaluated using the post hoc Bonferroni test (P < 0.05).

Results

On comparing sialic acid levels among the three groups, stage 2 showed the highest mean (8.61) compared with the other two groups and was highly significant (P < 0.001). On the contrary, IL10 when compared to stage 1 and 2 periodontitis revealed insignificant change.

Conclusion

The value of IL10 was higher as patients progressed from health to periodontitis.

Characterization of Cytokines and Proliferation Marker Ki67 in Cleft Affected Lip Tissue

Backgroundandobjectives: Cleft lip palate takes the second place among all anomalies. The complex appearance of cytokines and proliferation markers has still not been clarified despite their possible crucial role in cleft tissue. Therefore, the aim of work was the detection of appearance of pro- and anti-inflammatory cytokines and proliferation marker Ki67, and their inter-correlations in cleft affected lip (CAL). MaterialsandMethods: The lip material was obtained from 16 children aged before primary dentition during plastic surgery. Control was obtained from 7 non-CAL oral tissue. Tissues were stained for IL-1, IL-4, IL-6, IL-8, IL-10 and Ki67 immunohistochemically. Non-parametric statistic, Mann–Whitney and Spearman’s coefficient were used. Results: All cytokines positive cells were observed more into the epithelium. Statistically significant difference was seen between epithelial IL-1, IL-10, IL-8 and Ki67 positive cells and IL-10-, IL-4-containing connective tissue cells in comparison to the control. Strong positive correlation was detected in CAL epithelium between IL-10 and IL-8, IL-10 and IL-4, IL-10 and IL-1, IL-1 and IL-8, IL-1 and IL-4, IL-4 and IL-8, IL-8 and Ki67, IL-10 and Ki67, but moderate—in connective tissue between IL-1 and IL-10, IL-1 and IL-4. Conclusions: The CAL epithelium is the main source for the interleukins. Rich similar expression of IL-1 and IL-10 suggests the balance between pro-and anti-inflammatory tissue response on basis of dysregulated tissue homeostasis (increase of IL-8). The correlations between the different ILs-1, -4, -8, -10 in CAL epithelium seem to indicate the self-protection compensatory mechanism for intensification of local inflammatory-immune response without involvement of IL-6. The correlations between Ki67 and cytokines indicate the involvement of IL-8 and IL-10 in stimulation of cellular proliferation. IL-4 and IL-10 expression from CAL connective tissue simultaneously to IL-1, IL-4 and IL-10 inter-correlations there suggests the intensification of local immune response regulated probably by main pro-inflammatory cytokine—IL-1.

The role of three interleukin 10 gene polymorphisms (- 1082 A > G, - 819 C > T, - 592 A > C) in the risk of chronic and aggressive periodontitis: a meta-analysis and trial sequential analysis

Background

Periodontitis is a major oral health problem and it is considered as one of the reasons for tooth loss in developing and developed nations. The objective of the current review was to investigate the association between IL10 polymorphisms − 1082 A > G (rs1800896), -819C > T (rs1800871), − 592 A > C (rs1800872) and the risk of either chronic periodontitis or aggressive periodontitis.

Methods

This is a meta- analysis study, following the preferred reporting items for systematic reviews and meta- analyses (PRISMA). Relevant studies were searched in the health related electronic databases. Methodological quality of the included studies were assessed using the Newcastle-Ottawa Scale. For individual studies, odds ratio (OR) and its 95%confidence interval (CI) were calculated to assess the strength of association between IL10 polymorphisms (− 1082 A > G, -819C > T, − 592 A > C) and the risk of periodontitis. For pooling of the estimates across studies included, the summary OR and its 95% CIs were calculated with random-effects model. The pooled estimates were done under four genetic models such as the allelic contrast model, the recessive model, the dominant model and the additive model. Trial sequential analysis (TSA) was done for estimation of the required information size for this meta-analysis study.

Results

Sixteen studies were identified for this review. The included studies were assessed to be of moderate to good methodological quality. A significant association between polymorphism of IL10–1082 A > G polymorphism and the risk of chronic periodontitis in the non-Asian populations was observed only in the recessive model (OR,1.42; 95% CI:1.11, 1.8,I²: 43%). The significant associations between − 592 A > C polymorphism and the risk of aggressive periodontitis in the non-Asian populations were observed in particular genetic models such as allele contrast (OR, 4.34; 95%CI:1.87,10.07,I²: 65%) and recessive models (OR, 2.1; 95% CI:1.16, 3.82,I²: 0%). The TSA plot revealed that the required information size for evidence of effect was sufficient to draw a conclusion.

Conclusions

This meta-analysis suggested that the IL10–1082 A > G polymorphism was associated with chronic periodontitis CP risk in non-Asians. Thus, in order to further establish the associations between IL10 (− 819 C > T, − 592 A > C) in Asian populations, future studies should include larger sample sizes with multi-ethnic groups.

Electronic supplementary material

The online version of this article (10.1186/s12903-018-0637-9) contains supplementary material, which is available to authorized users.

Immune response mediated by Th1 / IL-17 / caspase-9 promotes evolution of periodontal disease

INTRODUCTION

Periodontitis is characterized by inflammatory mediators beyond T lymphocyte function and phenotype (Th1/Th2/Th17). The clinical diversity in periodontitis makes it difficult to characterize the immune response in patients. This study evaluated the profile of the adaptive immune response in the periodontal disease model.

METHODS

72 rats (Wistar) were divided into a control group (CTL/day 0) and periodontitis (PD15/15 days and PD60/60 days). In the PD15 and PD60 groups, periodontal disease was induced by ligature with a silk thread placed in the cervical region of the upper first molar. After euthanasia, the periodontal tissue was analyzed by flow cytometry (CD4, CD8, CD25, CD44), semi-quantitative RT-PCR (T-bet, GATA-3, RORγt), semi-quantitative RT-PCR and ELISA IFN-γ, TNF-α, IFN-γ, IL-4, IL-6, IL-10, IL-17) and by Western blotting (Caspase-9, PCNA).

RESULTS

The number of CD4⁺CD25⁺, CD4⁺CD44⁺, CD8⁺CD25⁺ and CD8⁺CD44⁺ cells and expression levels of T-bet and GATA-3 are increased in the PD60 group compared to PD15 and CTL. The RORγ-t gene transcript increased in the PD15 group in relation to PD60 and CTL. The cytokines IFN-γ, TNF-α and IL-17 increased in the PD60 group in relation to PD15. The expression of Caspase-9 was higher in the PD60 group than in PD15.

CONCLUSIONS

The results suggest that the evolution of gingivitis to periodontitis is related to the accumulation of activated Th1 cells (IFN-γ and TNF-α) associated with the presence of increased IL-17. Studies with inhibitors of these cytokines in periodontal disease may lead to therapy directed at blocking the inflammatory process in this pathology, interrupting bone loss.

Stem cell-like populations and immunoregulatory molecules in periodontal granulation tissue

BACKGROUND AND OBJECTIVES

Determine the presence of mesenchymal stem cells (MSCs) in healthy periodontal tissue and periodontal granulation tissue (GT) and explore associations between immuno-regulatory molecules and selected subgingival microorganisms.

MATERIAL AND METHODS

Mesenchymal stem cells were isolated, propagated and characterised by flow cytometry from a region of healthy gingival tissue and inflamed GT of 10 systemically healthy non-smokers with chronic periodontitis. Tissue levels of immunoregulatory molecules were determined by qPCR and Gingival Crevicular Fluid (GCF) levels by ELISA. Subgingival plaque levels of periodontal pathogens were determined by qPCR RESULTS: Cells with MSC-properties were isolated from both inflamed GT and healthy gingival (G) tissue. A pro-inflammatory process predominated in GT which was partly reflected in GCF and putative periodontal pathogens were higher at diseased sites. However, there was no significant difference in surface levels of mesenchymal (CD90, CD73, CD146, CD271, STRO-1), endothelial (CD105, CD106), hematopoietic (CD34, CD45) and embryonic (SSEA-4) stem cell markers between MSCs isolated from GT and G tissue.

CONCLUSION

Periodontal lesions, albeit inflamed, retain healing potential as inferred by the presence of MSC-like cells with similar immunophenotypic characteristics to those found in healthy periodontal tissue. Therefore, there might be merits for healing in preserving sufficient GT in-situ during periodontal surgery.

Macrophage Polarization Alters Postphagocytosis Survivability of the Commensal Streptococcus gordonii

Oral streptococci are generally considered commensal organisms; however, they are becoming recognized as important associate pathogens during the development of periodontal disease as well as being associated with several systemic diseases, including as a causative agent of infective endocarditis. An important virulence determinant of these bacteria is an ability to evade destruction by phagocytic cells, yet how this subversion occurs is mostly unknown. Using Streptococcus gordonii as a model commensal oral streptococcus that is also associated with disease, we find that resistance to reactive oxygen species (ROS) with an active ability to damage phagosomes allows the bacterium to avoid destruction within macrophages. This ability to survive relies not only on the ROS resistance capabilities of the bacterium but also on ROS production by macrophages, with both being required for maximal survival of internalized bacteria. Importantly, we also show that this dependence on ROS production by macrophages for resistance has functional significance: S. gordonii intracellular survival increases when macrophages are polarized toward an activated (M1) profile, which is known to result in prolonged phagosomal ROS production compared to that of alternatively (M2) polarized macrophages. We additionally find evidence of the bacterium being capable of both delaying the maturation of and damaging phagosomes. Taken together, these results provide essential insights regarding the mechanisms through which normally commensal oral bacteria can contribute to both local and systemic inflammatory disease.

MyD88-mediated innate sensing by oral epithelial cells controls periodontal inflammation

Periodontal diseases are a class of non-resolving inflammatory diseases, initiated by a pathogenic subgingival biofilm, in a susceptible host, which if left untreated can result in soft and hard tissue destruction. Oral epithelial cells are the first line of defense against microbial infection within the oral cavity, whereby they can sense the environment through innate immune receptors including toll-like receptors (TLRs). Therefore, oral epithelial cells directly and indirectly contribute to mucosal homeostasis and inflammation, and disruption of this homeostasis or over-activation of innate immunity can result in initiation and/or exacerbation of localized inflammation as observed in periodontal diseases. Dynamics of TLR signaling outcomes are attributable to several factors including the cell type on which it engaged. Indeed, our previously published data indicates that oral epithelial cells respond in a unique manner when compared to canonical immune cells stimulated in a similar fashion. Thus, the objective of this study was to evaluate the role of oral epithelial cell innate sensing on periodontal disease, using a murine poly-microbial model in an epithelial cell specific knockout of the key TLR-signaling molecule MyD88 (B6^{K5Cre.MyD88plox}). Following knockdown of MyD88 in the oral epithelium, mice were infected with Porphorymonas gingivalis and Aggregatibacter actinomycetemcomitans by oral lavage 4 times per week, every other week for 6 weeks. Loss of oral epithelial cell MyD88 expression resulted in exacerbated bone loss, soft tissue morphological changes, soft tissue infiltration, and soft tissue inflammation following polymicrobial oral infection. Most interestingly while less robust, loss of oral epithelial cell MyD88 also resulted in mild but statistically significant soft tissue inflammation and bone loss even in the absence of a polymicrobial infection. Together these data demonstrate that oral epithelial cell MyD88-dependent TLR signaling regulates the immunological balance within the oral cavity under conditions of health and disease.

Cytokine profile in gingival crevicular fluid and plasma of patients with aggressive periodontitis

OBJECTIVE

This study aimed to determine the content of cytokines in gingival crevicular fluid (GCF) as well as in plasma of Sudanese patients with aggressive periodontitis (AgP) and healthy controls (HC).

MATERIALS AND METHODS

Nineteen AgP patients and 19 HC were included. The mean probing pocket depth and clinical attachment level of the GCF sampled sites in patients were both ≥5 mm. The GCF and plasma levels of 27 cytokines were determined using 27-multiplex fluorescent bead-based immunoassays. Ratios were calculated among cytokines of the T-helper cell subsets Th1 and Th2. Descriptive statistics, the Mann-Whitney U-test and Spearman's rho rank correlation coefficient analysis were used.

RESULTS

Interferon-γ was the only cytokine found in significantly lower levels in GCF of patients compared with HC. Levels of interleukin (IL)-10, IL-13, IL-1Ra, monocyte chemoattractant protein-1 (MCP-1), regulated on activation normal T-cell expressed and secreted (RANTES), granulocyte-colony-stimulating factor (G-CSF), and granulocyte-macrophage-CSF (GM-CSF) were significantly lower in plasma of AgP compared with HC. The ratios of Th1:Th2 in GCF and Treg:Th17 in plasma were significantly lower in AgP.

CONCLUSIONS

The lower levels of cytokines detected systemically in plasma of AgP patients may have an impact on the immune response. The lower ratio of Th1:Th2 cytokines in GCF samples of AgP patients suggests a role for Th2 at the local site of disease.

The silencing of cathepsin K used in gene therapy for periodontal disease reveals the role of cathepsin K in chronic infection and inflammation

BACKGROUND AND OBJECTIVE

Periodontitis is a severe chronic inflammatory disease and one of the most prevalent non-communicable chronic diseases that affects the majority of the world's adult population. While great efforts have been devoted toward understanding the pathogenesis of periodontitis, there remains a pressing need for developing potent therapeutic strategies for targeting this dreadful disease. In this study, we utilized adeno-associated virus (AAV) expressing cathepsin K (Ctsk) small hairpin (sh)RNA (AAV-sh-Ctsk) to silence Ctsk in vivo and subsequently evaluated its impact in periodontitis as a potential therapeutic strategy for this disease.

MATERIAL AND METHODS

We used a known mouse model of periodontitis, in which wild-type BALB/cJ mice were infected with Porphyromonas gingivalis W50 in the maxillary and mandibular periodontium to induce the disease. AAV-sh-Ctsk was then administrated locally into the periodontal tissues in vivo, followed by analyses to assess progression of the disease.

RESULTS

AAV-mediated Ctsk silencing drastically protected mice (> 80%) from P. gingivalis-induced bone resorption by osteoclasts. In addition, AAV-sh-Ctsk administration drastically reduced inflammation by impacting the expression of many inflammatory cytokines as well as T-cell and dendritic cell numbers in periodontal lesions.

CONCLUSION

AAV-mediated Ctsk silencing can simultaneously target both the inflammation and bone resorption associated with periodontitis through its inhibitory effect on immune cells and osteoclast function. Thereby, AAV-sh-Ctsk administration can efficiently protect against periodontal tissue damage and alveolar bone loss, establishing this AAV-mediated local silencing of Ctsk as an important therapeutic strategy for effectively treating periodontal disease.

Immunologic environment influences macrophage response to Porphyromonas gingivalis

Macrophages adapt both phenotypically and functionally to the cytokine balance in host tissue microenvironments. Recent studies established that macrophages contribute an important yet poorly understood role in the development of infection-elicited oral bone loss. We hypothesized that macrophage adaptation to inflammatory signals encountered before pathogen interaction would significantly influence the subsequent immune response of these cells to the keystone oral pathobiont Porphyromonas gingivalis. Employing classically activated (M1) and alternatively activated (M2) murine bone-marrow-derived macrophage (BMDMø), we observed that immunologic activation of macrophages before P. gingivalis challenge dictated phenotype-specific changes in the expression of inflammation-associated molecules important to sensing and tuning host response to bacterial infection including Toll-like receptors 2 and 4, CD14, CD18 and CD11b (together comprising CR3), major histocompatibility complex class II, CD80, and CD86. M2 cells responded to P. gingivalis with higher expression of tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, regulated on activation normal T cell expressed and secreted, and KC than M1 cells. M1 BMDMø expressed higher levels of interleukin-10 to P. gingivalis than M2 BMDMø. Functionally, we observed that M2 BMDMø bound P. gingivalis more robustly than M1 BMDMø. These data describe an important contribution of macrophage skewing in the subsequent development of the cellular immune response to P. gingivalis.

Gingival Toll-like receptor and cytokine messenger RNA levels in equine periodontitis and oral health

REASONS FOR PERFORMING STUDY

Equine periodontitis is a common and painful condition. However, the disease often goes unnoticed by owners and is thus a major welfare concern. The aetiopathogenesis of the condition remains poorly understood and has been investigated in few studies. The innate immune system is known to play an important role in human periodontitis, but its role in equine periodontitis has not been examined.

OBJECTIVES

To quantify the messenger (m)RNA levels of Toll-like receptors (TLRs) and cytokines in gingival tissue from orally healthy horses and those affected by periodontitis.

STUDY DESIGN

Observational study.

METHODS

Gingival tissue samples were taken post-mortem from 13 horses with no clinical signs of oral disease and 20 horses with periodontitis. mRNA levels of TLR2, TLR4 and TLR9 and cytokines interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), IL-4, IL-6, IL-10, IL-12, IL-17 and interferon-γ (IFN-γ) were determined using quantitative real-time PCR. The statistical significance of results was assessed using appropriate t tests.

RESULTS

mRNA levels of all TLRs and cytokines were upregulated in equine periodontitis. Significant increases in mRNA levels of TLR2, TLR9, IL-4, IL-10, IL-12 (P≤0.05) and IFN-γ (P≤0.01) were observed for both unweighted and age-weighted analyses of diseased gingival tissue samples compared with healthy gingival samples. In comparisons of samples of periodontitis lesions with healthy gingival control samples from the same horse, significant increases in mRNA levels of TLR4, TLR9, IL-10, IFN-γ (P≤0.05), TLR2, IL-1β and IL-12p35 (P≤0.01) were observed.

CONCLUSIONS

This study has provided an initial insight into the involvement of the immune system in equine periodontitis. Increased mRNA levels of TLR2, TLR4 and TLR9 indicate substantial microbial challenge in diseased gingival tissue. A mixed Th1/Th2/Th17 cytokine response is produced in equine periodontitis. Further studies are required to more fully characterise the role of the innate immune system in this disease.

Therapeutic Targets for Management of Periodontitis and Diabetes

The increasing incidence of diabetes mellitus (DM) and chronic periodontitis (CP) worldwide imposes a rethinking of individualized therapy for patients with both conditions. Central to bidirectional links between DM and CP is deregulated systemic inflammation and dysfunctional immune responses to altered-self and non-self. Control of blood glucose levels and metabolic imbalances associated with hyperglycemia in DM, and disruption of pathogenic subgingival biofilms in CP are currently the main therapeutic approaches for these conditions. Mounting evidence suggests the need to integrate immune modulatory therapeutics in treatment regimens that address the unresolved inflammation associated with DM and CP. The current review discusses the pathogenesis of DM and CP with emphasis on deregulated inflammation, current therapeutic approaches and the novel pro-resolution lipid mediators derived from Ω-3 polyunsaturated fatty acids.

Host response mechanisms in periodontal diseases

Periodontal diseases usually refer to common inflammatory disorders known as gingivitis and periodontitis, which are caused by a pathogenic microbiota in the subgingival biofilm, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola that trigger innate, inflammatory, and adaptive immune responses. These processes result in the destruction of the tissues surrounding and supporting the teeth, and eventually in tissue, bone and finally, tooth loss. The innate immune response constitutes a homeostatic system, which is the first line of defense, and is able to recognize invading microorganisms as non-self, triggering immune responses to eliminate them. In addition to the innate immunity, adaptive immunity cells and characteristic cytokines have been described as important players in the periodontal disease pathogenesis scenario, with a special attention to CD4⁺ T-cells (T-helper cells). Interestingly, the T cell-mediated adaptive immunity development is highly dependent on innate immunity-associated antigen presenting cells, which after antigen capture undergo into a maturation process and migrate towards the lymph nodes, where they produce distinct patterns of cytokines that will contribute to the subsequent polarization and activation of specific T CD4+ lymphocytes. Skeletal homeostasis depends on a dynamic balance between the activities of the bone-forming osteoblasts (OBLs) and bone-resorbing osteoclasts (OCLs). This balance is tightly controlled by various regulatory systems, such as the endocrine system, and is influenced by the immune system, an osteoimmunological regulation depending on lymphocyte- and macrophage-derived cytokines. All these cytokines and inflammatory mediators are capable of acting alone or in concert, to stimulate periodontal breakdown and collagen destruction via tissue-derived matrix metalloproteinases, a characterization of the progression of periodontitis as a stage that presents a significantly host immune and inflammatory response to the microbial challenge that determine of susceptibility to develop the destructive/progressive periodontitis under the influence of multiple behavioral, environmental and genetic factors.

Inflammatory and immune pathways in the pathogenesis of periodontal disease

The pathogenesis of periodontitis involves a complex immune/inflammatory cascade that is initiated by the bacteria of the oral biofilm that forms naturally on the teeth. The susceptibility to periodontitis appears to be determined by the host response; specifically, the magnitude of the inflammatory response and the differential activation of immune pathways. The purpose of this review was to delineate our current knowledge of the host response in periodontitis. The role of innate immunity, the failure of acute inflammation to resolve (thus becoming chronic), the cytokine pathways that regulate the activation of acquired immunity and the cells and products of the immune system are considered. New information relating to regulation of both inflammation and the immune response will be reviewed in the context of susceptibility to, and perhaps control of, periodontitis.

Inflammatory Mediators of Leprosy Reactional Episodes and Dental Infections: A Systematic Review

Reactional episodes in leprosy are a result of complex interactions between the immune system, Mycobacterium leprae, and predisposing factors, including dental infections. To determine the main inflammatory mediators in the immunopathological process of dental infections and leprosy reactions, we conducted a systematic review of primary literature published between 1996 and 2013. A three-stage literature search was performed (Stage I, "leprosy reactions" and "inflammatory mediators"; Stage II, "dental infections" and "inflammatory mediators"; and Stage III, "leprosy reactions," "dental infections," and "inflammatory mediators"). Of the 911 eligible publications, 10 were selected in Stage I, 68 in Stage II, and 1 in Stage III. Of the 27 studied inflammatory mediators, the main proinflammatory mediators were IL-6, IFN-γ, TNF-α, IL-1β, and IL-17; the main anti-inflammatory mediators were IL-10 and IL-4. Serum IL-6 and TNF-α concentrations were significant during periodontal and reactional lesion evolution; IFN-γ and IL-1β were associated with types 1 and 2 reactions and chronic periodontal disease. The proinflammatory mediators in dental infections and leprosy reactions, especially IL-6 and TNF-α, were similar across studies, regardless of the laboratory technique and sample type. IFN-γ and IL-1β were significant for leprosy reactions and periodontal diseases. This pattern was maintained in serum.

Identification of quantitative trait loci influencing inflammation-mediated alveolar bone loss: insights into polygenic inheritance of host-biofilm disequilibria in periodontitis

BACKGROUND AND OBJECTIVE

The relative contribution of genetic and environmental factors to the onset and progression of periodontitis is inconclusive. Despite the high prevalence, phenotypic heterogeneity and significant local and systemic implications of this disease, early detection and individualized therapy are problematic. Using a murine model of periodontitis in a panel of 17 recombinant inbred mice, the current study addressed the heritability of, and oral dysbiosis associated with, inflammation-mediated alveolar bone loss (iABL), the hallmark of periodontitis.

MATERIAL AND METHODS

Quantitative trait locus (QTL) genomics and quantitative PCR for over 99% of known murine oral microbiota were used.

RESULTS

It was found that iABL is a polygenic trait with 32.7% heritability. One suggestive QTL, nicknamed inflammation-mediated alveolar bone loss locus (iABLL), was identified on chromosome 2. Eleven genes involved in innate immune responses and bone metabolism, particularly related to macrophage and osteoblast function, namely Etl4, Pdss1, Cobll1, 9330158F14Rik, Xirp2, Stk39, Mettl5, Metapl1, Itga6, Pdk1 and Sp3, were found in the iABLL using cis expression QTL and nonsynonymous single nucleotide polymorphism analyses. Specific oral microbiome shifts in saliva and tongue mucosa are associated with disease in this model.

CONCLUSION

Our results indicate that complex host-biofilm interactions generate pathogenic states that extend beyond subgingival biofilms and periodontal tissues. Although no temporal relationship between the onset of iABL and microbiome changes were established, our findings suggest that host factors may be responsible for pathogenic shifts in subgingival biofilms when persistent and undisturbed.

Macrophage subsets and osteoimmunology: tuning of the immunological recognition and effector systems that maintain alveolar bone

Chronic and aggressive periodontal diseases are characterized by the failure to resolve local inflammation against periodontopathogenic bacteria in the subgingival biofilm. Alveolar bone resorption is associated with altered innate and adaptive immune responses to periodontal pathogens. Macrophage-derived cytokines, chemokines and growth factors, present in both destructive and reparative phases of periodontitis, are elevated in numerous animal and human studies. Macrophage polarization to either a predominantly pro-inflammatory or anti-inflammatory phenotype may be a critical target for monitoring disease activity, modulating immune responses to subgingival biofilms in patients at risk and reducing alveolar bone loss.

Effect of non-surgical periodontal treatment on visfatin concentrations in serum and gingival crevicular fluid of patients with chronic periodontitis and type 2 diabetes mellitus

BACKGROUND

This study aims to assess visfatin concentrations in serum and gingival crevicular fluid (GCF) and investigate this relationship in patients with type 2 diabetes mellitus (T2DM) and chronic periodontitis (CP) before and after non-surgical periodontal treatment.

METHODS

Fifty-four patients with T2DM and CP were recruited. The patients were randomly divided into two groups: treatment and control. Serum and GCF visfatin concentrations and glycated hemoglobin (HbA1c) levels were measured by enzyme-linked immunosorbent assay at different time points (at baseline and 3 and 6 months after non-surgical periodontal treatment).

RESULTS

Serum and GCF visfatin concentrations showed no significant differences between the groups at baseline (t test, P >0.05). A significant decline of visfatin in the treatment group was found in serum and GCF 3 months after non-surgical periodontal treatment (t test, P <0.01). Baseline and 3-month HbA1c levels were not significantly different, but at 6 months, a statistically significant difference was detected (t test, P >0.05).

CONCLUSIONS

The data suggest that non-surgical periodontal treatment is helpful for glucose control, an effect that may be associated with reduced visfatin in patients with T2DM and periodontitis. Furthermore, the data suggest that visfatin may be considered an inflammatory marker for periodontal diseases.

Pro-inflammatory, Th1, Th2, Th17 cytokines and dendritic cells: a cross-sectional study in chronic periodontitis

There are a limited number of studies correlating the different stages of dendritic cells (DC) maturation with cytokines in individuals presented chronic periodontitis (CP). The aim of the study was to evaluate the correlation among the expression of IL-2, IL-10, IL-4, IL-6, IFN-, TNF-α, and IL-17A with the presence of DC and mild-moderate or advanced CP. Gingival samples were obtained from 24 individuals with CP and six samples of normal mucosa (NM) overlapping third molar for controls of the levels of cytokines. Periodontal examination was performed. Immunohistochemical staining was carried out, revealing CD1a+ immature, Fator XIIIa+ immature, and CD83+ mature DCs. The inflammatory infiltrate was counted, and the cytokines were measured by flow cytometry. Densities of DCs and inflammatory infiltrate, cytokines, subtypes of CP, and clinical periodontal parameters were correlated and compared. IL-6 expression was correlated positively with the increased numbers of CD1a+ immature DCs. Levels of IL-2, TNF-α, IFN-, IL-10, and IL-17A were increased when compared with NM. The percentage of sites with clinical attachment level (CAL)>3 were positively correlated with densities of inflammatory infiltrate and negatively correlated with densities of immature DCs. IL-6 can contribute to the increase of the immature DCs in the CP. Higher levels of IL-2, TNF-α, IFN-, IL-10, and IL-17A cytokines were observed in CP. Higher densities of inflammatory infiltrate as well as lower densities of immature DCs can result in a more severe degree of human CP.

Association study between clinicopathological variables and periodontal breakdown in gingival pyogenic granuloma

OBJECTIVE

The aim was to investigate a possible association between the immunoexpression of interleukin (IL)-4 and clinicopathological parameters with the periodontal breakdown observed in gingival pyogenic granuloma (PG).

MATERIALS AND METHODS

Paraffin-embedded samples of gingival PG (n = 46) were prepared for histological and immunohistochemical assessment. Demographic and clinical parameters were assessed by criteria based on age stratum, gender, smoking habit, evolution course, location, lesion size, macroscopic appearance, predisposing factors, recurrence, and periodontal breakdown. Histological assessment included the appearance of epithelial lining, microvessel density, inflammatory infiltrate density, interstitial fibrosis, and histological arrangement. A staining intensity distribution (SID) score was used to assess IL-4 immunoreactivity. The association between candidate predictor variables and periodontal breakdown was analyzed individually and adjusted for confounding using a bivariate binary logistic regression model.

RESULTS

Mean IL-4 SID values were significantly increased for long-standing and large lesions, presence of periodontal breakdown, high microvessel density, and moderate-to-severe inflammatory infiltrate density. While bivariate and univariate analyses revealed a positive association of the evolution course ≥12 months, lesion size >1 cm, high microvessel density, moderate-to-severe inflammatory infiltrate density, and IL-4 SID score ≥8.04 with periodontal breakdown, after bivariate logistic regression analysis, only the evolution course ≥12 months, moderate-to-severe inflammatory infiltrate density, and IL-4 SID score ≥8.04 remained as robust predictors of periodontal damage. Confounding and interaction effects between candidate predictor variables were also noted.

CONCLUSION

These findings suggest that while evolution course, inflammatory infiltrate density, and the overexpression of IL-4 may act as predictors of periodontal breakdown in gingival PG, there are mutual confounding and synergistic biological interactive effects with respect to the lesion size and microvessel density in the susceptible host that may be also associated with the bone resorption and tissue destruction.

CLINICAL RELEVANCE

Although the first-line therapy of gingival PG continues to be the surgical excision, this approach poses unwanted complications such as severe mucogingival defects and recurrence. Hence, early diagnosis and detection of these three significant predictor variables as well as timely surgical excision might help prevent the periodontal tissue destruction observed in some of these lesions.

Smoking-related cotinine levels and host responses in chronic periodontitis

BACKGROUND AND OBJECTIVE

Smoking has been reported to increase the risk of periodontal disease by disrupting the balance of immune responses and tissue repair processes; however, this risk varies among smokers. Cotinine levels in saliva are routinely used to measure the level of smoking, and reflect the quantity of nicotine, and other smoking-related xenobiotics that challenge host systems. This study delineated characteristics of inflammatory mediators in saliva and serum antibody responses to both periodontal pathogens and commensal bacteria in smokers as they related to cotinine levels.

MATERIALS AND METHODS

This case-control study (n = 279) examined salivary inflammatory mediator responses [interleukin (IL)-1ß, IL-10, prostaglandin E2, myeloperoxidase and plasminogen activator inhibitor-1], and serum IgG antibody responses to three periodontal pathogens (Aggregatibacter actinomyce-temcomitans, Porphyromonas gingivalis, Treponema denticola) and five commensal oral microorganisms (Veillonella parvula, Streptococcus sanguis, Prevotella loescheii, Actinomyces naeslundii, Capnocytophaga ochracea).

RESULTS

The patients were stratified into health (n = 30), gingivitis (n = 55) and periodontitis (n = 184); cotinine levels correlated with reported smoking habits in health, less so with gingivitis, and were not correlated in periodontitis. Of the inflammatory mediators/acute phase proteins, only IL-1ß levels were positively associated (p < 0.001) with the pack years and cotinine levels. As might be predicted, patients with periodontitis smoked more (p < 0.001) and had higher levels of cotinine. IL-1ß and antibody to A. actinomycetemcomitans, P. gingivalis and T. denticola were significantly higher in the patients with periodontitis than either patients with gingivitis or who were healthy.

CONCLUSIONS

Generally, antibody to the pathogens and commensals was lower with decreased cotinine levels. Smoking exacerbated differences in both inflammatory mediators and three antibody in periodontal disease compared to healthy subjects.

Evaluation of serum ceruloplasmin in aggressive and chronic periodontitis patients

Background:

Pro-inflammatory markers are seen to increase in inflammatory diseases like periodontitis. Detecting an increase in these markers is one of the diagnostic modality. One such marker, which can be detected, is the ceruloplasmin. Ceruloplasmin induces hypoxia and generates oxygen radicals at the site of aggressive periodontitis. It also causes a state of hypoferremia leading to increase in the natural resistance of the body. The aim of this study was to evaluate the serum levels of cerruloplasmin in both aggressive and chronic periodontitis patients.

Materials and Methods:

Blood samples were collected from aggressive periodontitis patients (n = 20), chronic periodontitis patients (n = 20) and periodontally healthy patients (n = 20). The serum was extracted from all the blood samples and ceruloplasmin levels were spectroscopically evaluated through a new kinetic method, which used a norfloxacin based reagent.

Results:

Serum ceruloplasmin levels were found to be significantly higher in aggressive periodontitis patients (P > 0.05) than in chronic periodontitis patients (P > 0.05) even though increase in the level of ceruloplasmin was found in chronic periodontitis. Periodontally healthy patients did not show increase in the levels of serum ceruloplasmin. The levels of serum ceruloplasmin also increased with the disease severity whose manifestations were increased bleeding on probing, increased pocket depth and increased attachment loss.

Conclusion:

Serum ceruloplasmin levels increased in both aggressive and chronic periodontitis patients, but more in aggressive periodontitis patients making it a potential marker for diagnosis of periodontitis.

Capsaicin inhibits Porphyromonas gingivalis growth, biofilm formation, gingivomucosal inflammatory cytokine secretion, and in vitro osteoclastogenesis

The prevention and treatment of periodontitis requires not only the control of causative pathogens, especially Porphyromonas gingivalis, but also the regulation of inflammatory immune response. Investigating auxiliary drugs for periodontitis during conventional treatments is, thus, quite important. Capsaicin, an agonist for the vanilloid receptor subtype 1 (TRPV1), due to its bacteriostatic activity against Gram-negative bacteria and anti-inflammatory effects, appears to be a promising drug. In this work, the antimicrobial activity of capsaicin against P. gingivalis and biofilm formation, inflammatory cytokine levels in experimental periodontitis, osteoclast precursor proliferation, and osteoclastogenesis in vitro were fully investigated. The results showed that capsaicin inhibited P. gingivalis growth with a minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of 16 and 64 mg/l, respectively. Capsaicin also inhibited P. gingivalis biofilm formation, with minimum biofilm inhibition concentrations MBIC50 and MBIC90 of 16 and 32 mg/l, respectively, and reduced pre-formed biofilms' viability with a minimum biofilm reduction concentration MBRC50 of 64 mg/l, as demonstrated by confocal laser scanning microscopy. In experimental periodontitis, except for IL-10, TNF-α, IL-1β, IL-6, IL-12, and iNOS were depressed after capsaicin treatment. Moreover, capsaicin also suppressed osteoclast precursor proliferation and osteoclastogenesis, as demonstrated by NF-ĸB p65. However, this favorable effect was attenuated by the TRPV1 antagonist, camphor. It, thus, suggests that capsaicin is a potential drug for the auxiliary treatment of periodontitis. TRPV1 activation may involve in beneficial roles of capsaicin on periodontitis.

The role of RgpA in the pathogenicity of Porphyromonas gingivalis in the murine periodontitis model

AIM

To investigate the in vivo role of gingipains in Porphyromonas gingivalis' virulence, and suggest a possible host mechanisms through which the bacteria cause alveolar bone loss.

MATERIALS AND METHODS

Mice were orally infected with P. gingivalis wild type, or the gingipains mutants (RgpA⁻, Kgp⁻, RgpA⁻/Kgp⁻). Mice were analysed for alveolar bone loss using micro-computed tomography. The molecular effects of the proteases were evaluated using the subcutaneous chamber model. Mice were infected with P. gingivalis wild type or mutants. Exudates were analysed for cytokine and leukocytes levels, in vivo phagocytosis, P. gingivalis survival and serum anti-P. gingivalis IgG titres.

RESULTS

Only RgpA-expressing bacteria induced significantly alveolar bone loss, and suppressed phagocytosis resulting in increased survival of P. gingivalis in the chamber exudates. In addition, RgpA-expressing bacteria induced higher levels of leukocytes and cytokines 2 h post-infection, and reduced levels of serum anti-P. gingivalis IgG titres 7 days post-infection.

CONCLUSIONS

Our findings showed that elimination of RgpA from P. gingivalis diminished inflammation, but augmented phagocytosis and antibody titres, coincidental with reduced alveolar bone loss. These findings support the hypothesis that RgpA is a critical virulence factor in the pathogenesis of experimental periodontitis in mice.

Aggregatibacter actinomycetemcomitans lipopolysaccharide stimulated epithelial cells produce interleukin-15 that regulates T cell activation

OBJECTIVE

Oral epithelial cells act not only as mechanical barriers but also as immunological barriers by producing various mediators such as cytokines. Since, in periodontal disease, limited information is available regarding the role of oral epithelial cell-derived cytokines on T cell activation, we investigated the responses of human T cells (Jurkat cell) to cytokines in KB cells (an oral epithelial cell line) that had been stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS).

DESIGN

To evaluate T cell activation in response to the culture supernatant of KB cells, we examined cell proliferation and interferon gamma (IFN-γ) production, which is closely related to periodontal disease, in Jurkat cells. Culture supernatant of LPS-stimulated KB cells enhanced cell proliferation and IFN-γ production in Jurkat cells. To determine the active component within the culture supernatant, the production of epithelial cell-derived cytokines, interleukin-12 (IL-12), IL-15 and IL-18, in LPS-stimulated KB cells was analysed.

RESULTS

IL-15, but not IL-18, was significantly increased in the culture supernatant of LPS-stimulated KB cells. Moreover, additional anti-IL-15 neutralizing antibody abolished culture supernatant-induced IFN-γ expression in Jurkat cells.

CONCLUSION

These results suggest that periodontal pathogens induce the production of IL-15 from epithelial cells, and leading the activation of T cells in periodontal lesions.