Epstein-Barr virus in oral diseases

Prevalence of Epstein Barr Virus and Herpes Simplex Virus Among Human Papillomavirus Negative Oral Cancer Patients: A Cross-Sectional Study from South India

The high incidence of oral carcinomas is due to its multifactorial etiology and the presence of various risk factors. Human Papillomavirus (HPV) has a proven role in the pathogenesis of oral carcinomas, but in the recent times there has been an increasing incidence of oral cancers who are negative for HPV infection. Also, these patients are non-smokers and non-drinkers so it could be speculated that these oral cancers are due to some other etiological factor probably of other viral infections. Therefore, this study examined the prevalence of Epstein Barr Virus (EBV) and Herpes Simplex Virus (HSV) among oral cancer patients. This cross-sectional study was conducted from January 2019 to June 2020. Biopsy samples from 47 newly diagnosed untreated patients with oral malignancies were collected along with their demographic and clinicopathological information. DNA extracted from the biopsies was processed for nested PCR for the detection of EBV and HSV. All the samples tested negative for HPV and HSV infection. Nested PCR detected 29 cases (70.7%) to be positive for EBV. The non-cancerous adjacent tissues also were negative for HPV, EBV and HSV. The prevalence of EBV was found to be more in males (62.1%) and the highest number of cases was of the left buccal mucosa compromising 34% of the total cases. From the present study it can be concluded that EBV but not HSV infection is associated with an increased risk of developing oral cancers. Although, 70.7% of the patients were found to be positive for EBV whether the viral infection played any role in the driving the malignancy needs to be further elucidated.

Detection of Epstein-Barr virus infection in primary junctional epithelial cell cultures

Background

Junctional epithelium (JE) provides the front-line defense against pathogens invading periodontium. The breakdown of the JE barrier is the hallmark of periodontitis. Recent studies have implicated the Epstein-Barr virus (EBV) as one of the etiopathogenetic factors of periodontitis. EBV exhibits tropism for two target cells in vivo: B cells, where it primarily remains latent, and epithelial cells, where viral replication occurs.

Objective

Our knowledge of junctional epithelial cell (JEC) infection with EBV has been limited by the difficulty of generating cell cultures and the inability to infect JECs in vitro readily.

Design

To study EBV infection in JECs, we developed human JEC cultures derived from a periodontitis patient. Furthermore, we established a successful contact-free co-culture infection model between the EBV-donor B95-8 cell line and the EBV-permissive JEC culture. JECs and EBV infection of JECs were detected using immunofluorescent staining of cytokeratin 19 and EBNA1, respectively. In addition, EBV infection was confirmed by RT-qPCR for EBNA1, LMP1, and BZLF1 expression.

Results and conclusions

Our results suggest that the infection of JECs with EBV can occur in an in vitro experimental model. These outcomes have the potential to enhance our understanding of EBV's involvement in periodontitis and advance periodontal research.

Herpesvirus-Related Lesions of the Oral Mucosa

The human herpesvirus (HHV) family is a group of enveloped DNA viruses containing 8 members known to produce oral mucosal lesions. Following initial exposure, which may result in symptomatic primary infection, the viruses establish latency within specific cells/tissues. After reactivation, herpesviruses can cause localized symptomatic or asymptomatic recurrent (secondary) infections or diseases. HHV may have a significant role in the cause of oral mucosal infectious diseases in immunocompromised patients. This article discusses the role of those herpesviruses that can induce oral mucosal lesions, with focus on the clinical features and treatment/management.

Comparative real-time PCR quantification of cytomegalovirus in severe early childhood caries and caries-free children

PURPOSE

The present study was undertaken to evaluate cytomegalovirus (CMV) load in carious lesions in children with severe early childhood caries (S-ECC) and compare it with caries-free (CF), healthy children, by quantitative real-time polymerase chain reaction (PCR).

MATERIALS AND METHODS

Dental plaque samples were collected from 57 subjects including S-ECC (n = 33) and CF (n = 24) patients. The two groups were matched in terms of age, gender, and socioeconomic status. After deoxyribonucleic acid (DNA) extraction, SYBR Green real-time PCR was used to quantify CMV DNA.

RESULTS

The CMV DNA was detected in seven patients in the S-ECC group. The mean of decayed, missing, and filled tooth surfaces (dmfs) was 11.90 ± 5.95 in the S-ECC group. There was no significant difference in gender between the two groups. There was a significant relationship between CMV positivity in children and the S-ECC group (p = 0.043).

CONCLUSION

Results of this study suggest a relationship between the presence of CMV in the oral cavity and S-ECC. We can design clinical trials to confirm these results and improve children's dental care.

Potential Role of Epstein–Barr Virus in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma: A Scoping Review

Though the oral cavity is anatomically proximate to the nasal cavity and acts as a key reservoir of EBV habitation and transmission, it is still unclear whether EBV plays a significant role in oral carcinogenesis. Many studies have detected EBV DNA in tissues and exfoliated cells from OSCC patients. However, very few studies have investigated the expression of functional EBV proteins implicated in its oncogenicity. The most studied are latent membrane protein 1 (LMP-1), a protein associated with the activation of signalling pathways; EBV determined nuclear antigen (EBNA)-1, a protein involved in the regulation of gene expression; and EBV-encoded small non-polyadenylated RNA (EBER)-2. LMP-1 is considered the major oncoprotein, and overexpression of LMP-1 observed in OSCC indicates that this molecule might play a significant role in oral carcinogenesis. Although numerous studies have detected EBV DNA and proteins from OSCC and oral potentially malignant disorders, heterogeneity in methodologies has led to discrepant results, hindering interpretation. Elucidating the exact functions of EBV and its proteins when expressed is vital in establishing the role of viruses in oral oncogenesis. This review summarises the current evidence on the potential role of EBV in oral oncogenesis and discusses the implications as well as recommendations for future research.

Viruses, periodontitis, and comorbidities

Seminal studies published in the 1990s and 2000s explored connections between periodontal diseases and systemic conditions, revealing potential contributions of periodontal diseases in the initiation or worsening of systemic conditions. The resulting field of periodontal medicine led to the publication of studies indicating that periodontal diseases can influence the risk of systemic conditions, including adverse pregnancy outcomes, cardiovascular and respiratory diseases, as well as Alzheimer disease and cancers. In general, these studies hypothesized that the periodontal bacterial insult and/or the associated proinflammatory cascade could contribute to the pathogenesis of these systemic diseases. While investigations of the biological basis of the connections between periodontal diseases and systemic conditions generally emphasized the bacteriome, it is also biologically plausible, under an analogous hypothesis, that other types of organisms may have a similar role. Human viruses would be logical "suspects" in this role, given their ubiquity in the oral cavity, association with periodontal diseases, and ability to elicit strong inflammatory response, compromise immune responses, and synergize with bacteria in favor of a more pathogenic microbial consortium. In this review, the current knowledge of the role of viruses in connecting periodontal diseases and systemic conditions is examined. We will also delve into the mechanistic basis for such connections and highlight the importance of those relationships in the management and treatment of patients.

Evaluation of the periodontal viruses in cardiovascular patients associated with periodontitis

OBJECTIVES

The current study aims in evaluating the prevalence of Epstein-barr virus (EBV), Cytomegalovirus (CMV) and Herpes simplex virus (HSV) in periodontitis and/or Coronary artery disease (CAD) patients to compare with their healthy controls and insist their significance in the same.

METHODOLOGY

Two hundred and forty patients were divided into 4 groups. Non-periodontitis+non-cardiac (NP+NC) =60 patients, periodontitis+non-cardiac patients (P+NC)=60 patients, non-periodontitis+cardiac patients (NP+C)=60 patients and periodontitis+cardiac (P+C)=60 patients. Demographic variables, cardiac and periodontal parameters were recorded. EBV, CMV and HSV were evaluated in the sub- gingival plaque samples using RT-PCR (Real time polymerase chain reaction) and compared between the groups. The results were statistically analysed using Students t test, Pearson's chi square, Turkey post hoc analysis and multiple logistic regression analysis.

RESULTS

The demographic variables did not differ significantly between the groups, except for age. Systolic blood pressure, Diastolic blood pressure, Low density lipoprotein, Random blood sugar were significantly higher in NP+C and P+C (p≤0.05). The Plaque Index, Probing Pocket Depth and Clinical Attachment Loss (p≤0.05) were significantly higher in P+NC and P+C. EBV and CMV was significantly higher in the two periodontitis groups P+NC and P+C (p-value=0.000). HSV was significantly higher in the two cardiac groups (NP+C and P+C) (p≤0.05). Multiple logistic regression analysis revealed a significant association between EBV and CAL (p≤0.05).

CONCLUSION

The study concluded that higher prevalence of EBV and CMV were found in groups with periodontitis patients. This indicates the significant role of the viruses in periodontitis as confirmed by association of EBV and CAL. The viruses were said to be highest in periodontitis patients with CAD. This could pave a new link in the risk of CAD in periodontitis patients.

Epstein-Barr Virus Promotes the Production of Inflammatory Cytokines in Gingival Fibroblasts and RANKL-Induced Osteoclast Differentiation in RAW264.7 Cells

Periodontitis is an inflammatory condition that causes the destruction of the supporting tissues of teeth and is a major public health problem affecting more than half of the adult population worldwide. Recently, members of the herpes virus family, such as the Epstein–Barr virus (EBV), have been suggested to be involved in the etiology of periodontitis because bacterial activity alone does not adequately explain the clinical characteristics of periodontitis. However, the role of EBV in the etiology of periodontitis is unknown. This study aimed to examine the effect of inactivated EBV on the expression of inflammatory cytokines in human gingival fibroblasts (HGFs) and the induction of osteoclast differentiation. We found that extremely high levels of interleukin (IL)-6 and IL-8 were induced by inactivated EBV in a copy-dependent manner in HGFs. The levels of IL-6 and IL-8 in HGFs were higher when the cells were treated with EBV than when treated with lipopolysaccharide and lipoteichoic acid. EBV induced IκBα degradation, NF-κB transcription, and RAW264.7 cell differentiation into osteoclast-like cells. These findings suggest that even without infecting the cells, EBV contributes to inflammatory cytokine production and osteoclast differentiation by contact with oral cells or macrophage lineage, resulting in periodontitis onset and progression.

The Underrated Salivary Virome of Men Who Have Sex With Men Infected With HIV

Salivary virome is important for oral ecosystem, but there are few reports on people living with HIV. We performed metagenomic sequencing to compare composition and functional genes of salivary virobiota between one HIV-negative and four HIV-positive groups in which participants were all men who have sex with men (MSM) with different immunosuppression statuses (five samples per group) to find the evidence that salivary virobiota plays a role in the pathogenesis of oral disease. Acute-stage subjects achieved a positive result of HIV RNA, but HIV antibody negative or indeterminate, whereas individuals with mild, moderate, and severe immunosuppression exhibited CD4⁺ T-lymphocyte counts of at least 500, 200–499, and less than 200 cells/μL or opportunistic infection, respectively. The results showed the composition of salivary virus genera in subjects with mild immunosuppression was the most similar to that in healthy people, followed by that in the acute stage; under severe immunosuppression, virus genera were suppressed and more similar to that under moderate immunosuppression. Furthermore, abnormally high abundance of Lymphocryptovirus was particularly obvious in MSM with HIV infection. Analysis of KEGG Pathway revealed that Caulobacter cell cycle, which affects cell duplication, became shorter in HIV-positive subjects. It is worth noting that in acute-stage participants, protein digestion and absorption related to the anti-HIV-1 activity of secretory leukocyte protease inhibitor was increased. Moreover, in the severely immunosuppressed subjects, glutathione metabolism, which is associated with the activation of lymphocytes, was enhanced. Nevertheless, the ecological dysbiosis in HIV-positive salivary virobiota possibly depended on the changes in blood viral load, and salivary dysfunction of MSM infected with HIV may be related to CD4 counts. Ribonucleoside diphosphate reductase subunit M1 in purine metabolism was negatively correlated, though weakly, to CD4 counts, which may be related to the promotion of HIV-1 DNA synthesis in peripheral blood lymphocytes. 7-Cyano-7-deazaguanine synthase in folate biosynthesis was weakly positively correlated with HIV viral load, suggesting that this compound was produced excessively to correct oral dysfunction for maintaining normal cell development. Despite the limited number of samples, the present study provided insight into the potential role of salivary virome in the oral function of HIV infected MSM.

Viruses of the oral cavity: Prevalence, pathobiology and association with oral diseases

The human oral cavity contains a plethora of habitats and tissue environments, such as teeth, tongue, and gingiva, which are home to a rich microbial flora including bacteria, fungi, and viruses. Given the exposed nature of the mouth, oral tissues constantly encounter infectious agents, forming a complex ecological community. In the past, the discussion of microbiological aspects of oral disease has traditionally focused on bacteria and fungi, but viruses are attracting increasing attention as pathogens in oral inflammatory diseases. Therefore, understanding viral prevalence, pathogenicity, and preference regarding oral tissues is critical to understanding the holistic effects of viruses on oral infections. Recent investigations have demonstrated the abundance of certain viruses in oral inflammatory diseases, suggesting an association between viruses and disease. Human herpesviruses are the most extensively studied viruses in different oral inflammatory diseases. However, challenges in viral detection and the lack of reproducible in vitro and in vivo infection models have limited our progress in understanding viruses and their contribution to oral diseases. This review presents a summary of major mammalian viruses and associated diseases in the human oral cavity. The emergence of a recent pathogen SARS-CoV-2 and its tropism for salivary and periodontal tissues further highlights the relevance of the oral cavity in host-pathogen interaction. Understanding how these different viruses present clinically and influence oral health will advance our understanding of multifactorial oral diseases and their association with viruses.

Oral and cutaneous manifestations of viral and bacterial infections: Not only COVID-19 disease

Globalization entails several medical problems along with economic and social complications. Migrations from other continents, increasing numbers of tourists worldwide, and importation of foreign parasites (eg, Aedes albopictus) have made diseases previously unknown in Europe a reality. The rapid spread of the coronavirus disease 2019 pandemic throughout the world is a warning that other epidemics are still possible. Most, if not all of these diseases, transmitted by viruses or bacteria, present with cutaneous symptoms and signs that are highly important for a speedy diagnosis, a fundamental concept for arresting the diseases and saving lives. Dermatologists play a significant role in delineating cutaneous and mucosal lesions that are often lumped together as dermatitis. We provide a review of many of these cutaneous and mucosal lesions that sometimes are forgotten or even ignored.

The oralome and its dysbiosis: New insights into oral microbiome-host interactions

The oralome is the summary of the dynamic interactions orchestrated between the ecological community of oral microorganisms (comprised of up to approximately 1000 species of bacteria, fungi, viruses, archaea and protozoa - the oral microbiome) that live in the oral cavity and the host. These microorganisms form a complex ecosystem that thrive in the dynamic oral environment in a symbiotic relationship with the human host. However, the microbial composition is significantly affected by interspecies and host-microbial interactions, which in turn, can impact the health and disease status of the host. In this review, we discuss the composition of the oralome and inter-species and host-microbial interactions that take place in the oral cavity and examine how these interactions change from healthy (eubiotic) to disease (dysbiotic) states. We further discuss the dysbiotic signatures associated with periodontitis and caries and their sequalae, (e.g., tooth/bone loss and pulpitis), and the systemic diseases associated with these oral diseases, such as infective endocarditis, atherosclerosis, diabetes, Alzheimer's disease and head and neck/oral cancer. We then discuss current computational techniques to assess dysbiotic oral microbiome changes. Lastly, we discuss current and novel techniques for modulation of the dysbiotic oral microbiome that may help in disease prevention and treatment, including standard hygiene methods, prebiotics, probiotics, use of nano-sized drug delivery systems (nano-DDS), extracellular polymeric matrix (EPM) disruption, and host response modulators.

Epstein-Barr Virus and Peri-Implantitis: A Systematic Review and Meta-Analysis

The exponential growth in the use of dental implants in the last decades has been accompanied by an increase in the prevalence of peri-implant disease. It appears that viruses may have pathogenic potential for the development of this pathology. The objective of this systematic review is to study the possible association between the presence of Epstein–Barr virus and the development of peri-implantitis. An electronic search was conducted in PubMed/MEDLINE, Scielo and Embase databases for cross-sectional and case–control studies in humans published up to and including 4 January 2021. Five studies were included in the qualitative analysis. The meta-analysis did not show a statistically significant difference regarding the prevalence of Epstein–Barr virus in the peri-implant sulcus between implants with peri-implantitis and healthy implants. In conclusion, no association between the human herpesvirus 4 and peri-implantitis was found. Further research on this topic is essential to develop more effective treatments.

Butyric Acid in Saliva of Chronic Periodontitis Patients Induces Transcription of the EBV Lytic Switch Activator BZLF1: A Pilot Study

BACKGROUND/AIM

Epstein-Barr virus (EBV) associates with human chronic periodontitis (CP) progression. We previously demonstrated that butyric acid (BA), produced by periodontopathic bacteria, induced EBV lytic switch activator BZLF1 expression. We investigated whether short chain fatty acids (SCFAs) in CP patients' saliva enabled EBV reactivation.

MATERIALS AND METHODS

Saliva was collected from seven CP patients and five periodontally healthy individuals. SCFAs were quantified using HPLC. BZLF1 mRNA and its pertinent protein ZEBRA were determined with Real-time PCR and western blotting. Histone H3 acetylation (AcH3) was further examined.

RESULTS

BZLF1 mRNA expression and transcriptional activity in EBV-infected Daudi cells were induced only when treated with the CP saliva. Among SCFAs, BA alone correlated significantly with the BZLF1 transcription (r=0.88; p<0.02). As expected, CP patients' saliva induced AcH3.

CONCLUSION

BA in saliva may play a role in EBV reactivation and hence contribute to EBV-related disease progression in CP patients.

Evidence linking the role of periodontal viruses in coronary artery disease with and without periodontitis

BACKGROUND

Viruses are considered to be a newer family associated with inflammatory diseases. Yet the role of periodontal viruses in coronary artery diseases (CAD) remains unclear. Thus, the current study aims to evaluate the prevalence of periodontal viruses and compare the same in cardiac samples of CAD patients with and without periodontitis.

METHODS

A total of 60 patients with CAD indicated for coronary artery bypass graft surgery (CABG) were included. These were grouped into 36 patients with healthy periodontium (CAD only) and 24 patients with periodontitis (CAD + P). The demographic variables, cardiac parameters and periodontal parameters were recorded. Cardiac tissue samples were collected during the CABG surgery and were analyzed by reverse transcriptase polymerase chain reaction for periodontal viruses such as Epstein-Barr virus (EBV), cytomegalovirus (CMV) and Herpes simplex virus. All the parameters were statistically analyzed.

RESULTS

Among the demographic variables, age was statistically significant between the groups. Plaque index, bleeding index, probing depth, and clinical attachment level (CAL) were significantly higher in CAD+P group (P ˂0.05). Periodontal viruses such as EBV and CMV were significantly higher (62.5% and 75% respectively, P ˂0.05) in the cardiac samples of the CAD+P than CAD only (25% and 47.2%, respectively). A significant association between EBV and CAL was revealed by multiple logistic regression analysis. (B = 0.374, P = 0.046) CONCLUSIONS: The results revealed a higher prevalence of periodontal viruses such as EBV and CMV in CAD patients with periodontitis suggesting it as one of the risk factors for CAD. This is supported by the fact that severity of periodontal disease (CAL) is associated with the presence of EBV in coronary artery plaque samples in the current study.

Relationship between herpesviruses and periodontal disease progression

AIM

To investigate the role of Epstein-Barr virus (EBV), cytomegalovirus (CMV), and anaerobic bacteria in the progression of periodontitis.

METHODS

Eighty-one adults with generalized moderate to severe periodontitis were randomly assigned to: oral hygiene or scaling and root planning ± placebo or polyunsaturated fatty acids fish oil. Subgingival plaque samples collected from three healthy and three disease sites at weeks 0, 16, and 28 and from sites demonstrating disease progression were analysed for EBV, CMV, P. gingivalis (Pg), T. forsythia (Tf), and T. denticola (Td) DNA using quantitative polymerase chain reaction.

RESULTS

Cytomegalovirus was detected in 0.3% (4/1454) sites. EBV was present in 12.2% of healthy sites (89/728) and 27.6% disease sites (201/726; p < .0001), but was in low copy number. Disease progression occurred in 28.4% of participants (23/81) and developed predominantly at sites identified as diseased (75/78; 96.2%). CMV and EBV were not associated with disease progression (p = .13) regardless of treatment. In contrast, disease sites were associated with higher levels of Pg, Td, Tf, and total bacteria, and sites that exhibited disease progression were associated with an abundance of Td and Tf (p < .04).

CONCLUSION

Disease progression was associated with Gram-negative anaerobic bacteria; not EBV or CMV.

EBV LMP1 in Gingival Epithelium Potentially Contributes to Human Chronic Periodontitis via Inducible IL8 Production

BACKGROUND/AIM

Human chronic periodontitis is a major health problem. Although some oral bacteria have been reported to be putative pathogens, Epstein-Barr virus (EBV) is reported to be associated with the progression of periodontitis. However, the role of EBV in the aetiology of periodontitis is unknown. Therefore, we investigated periodontal pathogenesis of EBV to confirm whether EBV-encoded latent membrane protein 1 (LMP1) induces Interleukin-8 (IL8) production in human gingival cells.

MATERIALS AND METHODS

Real-time polymerase chain reaction, luciferase assay, enzyme-linked immunosorbent assay (ELISA), and western blotting were performed for determining IL8 mRNA expression, nuclear factor kappa B (NF-ĸB) transcription, IL8 production, and the phosphorylation of NF-ĸB p65 and Inhibitor of kappa B alpha (IĸBα), respectively, in Ca9-22 human gingival epithelial cells. Two LMP1 mutants lacking C-terminal activating region (CATR) domains responsible for activating NF-ĸB were used.

RESULTS

Extremely high IL8 production was induced by LMP1 in time- and dose-dependent manner, where simultaneous phosphorylation of NF-κB p65 and IĸBα and transcription of NF-ĸB were observed. On the contrary, IL8 production and NF-ĸB transcription were drastically inhibited by dominant negative mutant of IĸBα. Moreover, the LMP1 mutants failed to induce IL8 production.

CONCLUSION

Our findings suggest that due to CATR domains, LMP1 contributes to the progression of periodontitis via IL8 production attributable to NF-ĸB activation.

How Does Epstein-Barr Virus Contribute to Chronic Periodontitis?

Chronic periodontitis is spreading worldwide and mutually interacts with systemic diseases like diabetes mellitus. Although periodontopathic bacteria are inevitable pathogens in their onset and progression, many cases are not ascribable to the virulence of these bacteria because the effect of plaque control is limited. In contrast, Epstein-Barr virus (EBV) in the periodontium has been correlated with chronic periodontitis and has recently been considered as a promising pathogenic candidate for this disease. However, several important questions have yet to be addressed. For instance, although EBV latently infects more than 90% of individuals over the world, why do patients with chronic periodontitis exclusively harbor progeny EBV in the oral cavity? In addition, how does latently infected or reactivated EBV in the periodontium relate to the onset or progression of chronic periodontitis? Finally, is periodontitis incurable because EBV is the pathogen for chronic periodontitis? In this review, we attempt to answer these questions by reporting the current understanding of molecular relations and mechanisms between periodontopathic bacteria and EBV reactivation in the context of how this relationship may pertain to the etiology of chronic periodontitis.

IFN-β secretion is through TLR3 but not TLR4 in human gingival epithelial cells

The oral cavity is home for a plethora of bacteria and viruses. Epithelial barriers encounter these micro-organisms and recognize them via pathogen recognition receptors (PRRs) that instigate antibacterial and antiviral responses. We and others have shown that human gingival epithelial cells (HGECs) express PRRs to defend invading pathogens. Among these PRRs, TLR2, TLR3 and TLR4 are highly expressed in HGECs and appear to be important based on our previous findings. IFN-β is one of the major type 1 interferons induced to defend viral attack. In this report, we sought to dissect TLR3 and TLR4 mediated secretion of IFN-β in HGECs. We stimulated HGECs with ultrapure LPS (TLR4 ligand) and Poly I:C (TLR3 ligand) for 24 h and supernatant was used to determine IFN-β secretion. We show that cells treated with Poly I:C induced IFN-β secretion but not cells treated with LPS. In addition, silencing of TLR3 prior to Poly I:C stimulation significantly downregulated IFN-β secretion. On the contrary, overexpression of MD2 and TLR4 in HGECs restored IFN-β secretion. Upon further evaluation, we found that TLR3 stimulation but not TLR4 induced the phosphorylation of interferon regulatory factor 3 (IRF3), which is critical for IFN-β secretion. We conclude that IFN-β secretion is through TLR3 and not via TLR4 in HGECs.

Herpesviruses and MicroRNAs: New Pathogenesis Factors in Oral Infection and Disease?

The oral cavity incessantly encounters a plethora of microorganisms. Effective and efficient oral innate and adaptive immune responses are incumbent to maintain healthy mucosa. A higher prevalence of Human Herpesviruses (HHV), a family of large enveloped DNA viruses, has been reported in multiple oral inflammatory diseases suggesting their involvement in disease progression. However, the viral components contributing to oral disease remain obscure. MicroRNAs (miRNA) are non-protein coding, single stranded ribonucleic acid (RNA) molecules that post-transcriptionally regulate diverse messenger RNAs. Thus, miRNAs can control large repertoire of biological processes. Changes in miRNA expression are associated with various oral infections and diseases. Cellular miRNAs can act as pro- or anti-viral factors and dysregulation of host miRNA expression occurs during herpesviruses infection. This strongly suggest a critical role of cellular miRNAs in host-herpesvirus interaction. Interestingly, HHV also encode multiple miRNAs (called viral miRNAs) that may play key role in host-pathogen interaction by modulating both host biological pathways and controlling viral life cycle. Recent studies from our laboratory have identified viral miRNAs (v-miRs) in diseased oral tissue biopsies and demonstrate their immunomodulatory roles. This review discusses the association of miRNAs (both host and viral) and herpesviruses in the pathogenesis of oral inflammatory diseases.

Role of Salivary Biomarkers in Oral Cancer Detection

Oral cancers are the sixth most frequent cancer with a high mortality rate. Oral squamous cell carcinoma accounts for more than 90% of all oral cancers. Standard methods used to detect oral cancers remain comprehensive clinical examination, expensive biochemical investigations, and invasive biopsy. The identification of biomarkers from biological fluids (blood, urine, saliva) has the potential of early diagnosis. The use of saliva for early cancer detection in the search for new clinical markers is a promising approach because of its noninvasive sampling and easy collection methods. Human whole-mouth saliva contains proteins, peptides, electrolytes, organic, and inorganic salts secreted by salivary glands and complimentary contributions from gingival crevicular fluids and mucosal transudates. This diagnostic modality in the field of molecular biology has led to the discovery and potential of salivary biomarkers for the detection of oral cancers. Biomarkers are the molecular signatures and indicators of normal biological, pathological process, and pharmacological response to treatment hence may provide useful information for detection, diagnosis, and prognosis of the disease. Saliva's direct contact with oral cancer lesions makes it more specific and potentially sensitive screening tool, whereas more than 100 salivary biomarkers (DNA, RNA, mRNA, protein markers) have already been identified, including cytokines (IL-8, IL-1b, TNF-α), defensin-1, P53, Cyfra 21-1, tissue polypeptide-specific antigen, dual specificity phosphatase, spermidine/spermineN1-acetyltransferase , profilin, cofilin-1, transferrin, and many more. However, further research is still required for the reliability and validation of salivary biomarkers for clinical applications. This chapter provides the latest up-to-date list of known and emerging potential salivary biomarkers for early diagnosis of oral premalignant and cancerous lesions and monitoring of disease activity.

Porphyromonas endodontalis reactivates latent Epstein-Barr virus

AIM

To determine whether Porphyromonas endodontalis can reactivate latent Epstein-Barr virus (EBV).

METHODOLOGY

The concentrations of short-chain fatty acids (SCFAs) in P. endodontalis culture supernatants were determined using high-performance liquid chromatography. A promoter region of BamHI fragment Z leftward open reading frame 1 (BZLF-1), which is a transcription factor that controls the EBV lytic cycle, was cloned into luciferase expression vectors. Then, the luciferase assay was performed using P. endodontalis culture supernatants. Histone acetylation using Daudi cells treated with P. endodontalis culture supernatants was examined using Western blotting. BZLF-1 mRNA and BamHI fragment Z EB replication activator (ZEBRA) protein were also detected quantitatively using real-time polymerase chain reaction (PCR) and Western blotting. Surgically removed periapical granulomas were examined to detect P. endodontalis, EBV DNA, and BZLF-1 mRNA expression using quantitative real-time PCR. Statistical analysis using Steel tests was performed.

RESULTS

The concentrations of n-butyric acid in P. endodontalis culture supernatants were significantly higher than those of other SCFAs (P = 0.0173). Using B-95-8-221 Luc cells treated with P. endodontalis culture supernatants, the luciferase assay demonstrated that P. endodontalis induced BZLF-1 expression. Hyperacetylation of histones was also observed with the culture supernatants. BZLF-1 mRNA and ZEBRA protein were expressed by Daudi cells in a dose-dependent manner after the treatment with P. endodontalis culture supernatants. P. endodontalis and BZLF-1 in periapical granulomas were also detected. The expression levels of BZLF-1 mRNA were similar to the numbers of P. endodontalis cells in each specimen.

CONCLUSIONS

n-butyric acid produced by P. endodontalis reactivated latent EBV.

Is periodontitis a risk indicator for cancer? A meta-analysis

Background

The aim of the present systematic review was to evaluate the hypothesis of an association between periodontitis and the development of cancer.

Methods

Two reviewers independently screened electronic and manual sources for pertinent articles. Primary outcome measures were the occurrence of neoplasm diagnosis in exposed and non-exposed groups, reported to evaluate association between cancer and periodontitis.

Results

Of the 490 initially retrieved papers 10 were included in the qualitative synthesis and eight in the quantitative synthesis; the eight papers covered six studies. Considering hazard ratios, a statistically significant association was found for all cancers studied (1.14; CI 95%: 1.04, 1.24), digestive tract cancer (1.34; CI 95%: 1.05, 1.72), pancreatic cancer (1.74; CI 95%: 1.21, 2.52), prostate cancer (1.25; CI 95%: 1.04, 1.51), breast cancer (1.11; CI 95%: 1.00, 1.23), corpus uteri cancer (2.20; CI 95%: 1.16, 4.18), lung cancer (1.24; CI 95%: 1.06, 1.45), hematological cancer (1.30; CI 95%: 1.11, 1.53), esophagus / oropharyngeal cancer pooled together (2.25; CI 95%: 1.30, 3.90) and Non-Hodgkin lymphoma (1.30; CI 95%: 1.11, 1.52).

Conclusions

Despite the sparse scientific evidence and considering the low statistical power of the results, this systematic review revealed a substantial lack of studies with standardized and comparable methods to speculate about the association between periodontitis and cancer; more studies are need in order to explore further the scientific evidence of such correlation.

Epstein-Barr virus (EBV)-encoded small RNAs (EBERs) associated with poor prognosis of head and neck carcinomas

BACKGROUND

Epstein-Barr virus (EBV) is the main cause of nasopharyngeal carcinoma (NPC), also found in other head and neck carcinomas (HNSCCs) where its role remains controversial.

RESULTS

EBV was found in 80% and 21% of the samples with PCR and ISH (in cancer cells), respectively. Eight of ISH-positive samples were not NPCs. EBER-RNA detection in carcinoma cells was associated with worse prognosis, whether or not NPCs were included. HPV/EBV and HSV/HPV coinfections associated with a shorter survival. LMP-1 expression, positive in 51% of samples did not correlate with the disease outcome.

MATERIALS AND METHODS

We analyzed EBV in 73 HNSCC samples with a known HPV and HSV-1 status, using in situ hybridization (ISH) and immunohistochemistry (IHC) for EBV-early transcripts (EBER) and LMP-1 protein, respectively. EBV-DNA was detected with a Luminex-based method. The results were correlated with HPV-status and disease outcome.

CONCLUSIONS

EBV is transcriptionally active in NPC cells but also in a subgroup of other HNSCCs.

Prevalence of Epstein-Barr virus DNA and Porphyromonas gingivalis in Japanese peri-implantitis patients

Background

Peri-implantitis (PI) is an inflammatory reaction associated with functional deterioration of supporting bones around the dental implant. Recent studies suggested Epstein–Barr virus (EBV) is involved in the pathogenesis of periodontitis. We investigated the association between EBV and Porphyromonas gingivalis in Japanese PI patients.

Methods

Fifteen periodontally healthy individuals, 15 healthy implant patients and 15 PI patients were recruited. Forty five subgingival plaque samples were collected from the deepest probing pocket depth (PPD) site from each patient. Real-time PCR was used to detect EBV DNA and P. gingivalis.

Results

EBV and P. gingivalis were detected in 7 and 3 PPD sites of the healthy controls, in 9 and 4 PPD sites of the healthy implants, and in 13 and 14 PPD sites of the PI patients. P. gingivalis and coexistence of EBV and P. gingivalis were detected significantly higher in the PI patients than healthy controls and healthy implant patients. EBV was detected significantly higher in the PI patients than healthy controls.

Conclusions

Higher levels of EBV and P. gingivalis were detected in PPD sites of PI patients. These results suggest that coexistence of EBV and P. gingivalis may serve pathogenic factors cause for PI in Japanese dental patients.

Considerations in the diagnosis of oral hairy leukoplakia-an institutional experience

OBJECTIVE

We report here the 10-year experience with oral hairy leukoplakia (OHL) at the Division of Oral and Maxillofacial Pathology at the University of North Carolina at Chapel Hill, NC, USA.

STUDY DESIGN

All the associated hematoxylin and eosin and Epstein-Barr virus encoding region in situ hybridization slides of OHL cases between January 1, 2008, and February 1, 2017, were retrieved and reviewed. Collected demographic characteristics, clinical presentation, medical and social histories were reviewed and reported.

RESULTS

Six OHL cases with confirmed in situ hybridization showed predilection for the lateral tongue. The study included 3 females and 3 males (mean age 50.5 years; age range 29-70 years). One patient had known HIV-positive status before biopsy was performed. Three patients had reported a history of heavy smoking. Other medical conditions reported were history of breast cancer, a long history of corticosteroid inhaler use for asthma treatment, high cholesterol, diabetes, and hypertension.

CONCLUSIONS

The findings of this study indicate the need to include OHL as a potential entity in the differential diagnosis of leukoplakic tongue lesions, regardless of the patient's HIV status. In addition, the presence of OHL in the patient requires investigation of various explanations for EBV infection, including immunosuppression caused by HIV infection or chronic steroid use.

Detection of cytomegalovirus, Epstein-Barr virus, and Torque Teno virus in subgingival and atheromatous plaques of cardiac patients with chronic periodontitis

BACKGROUND

Periodontitis and atherosclerosis represent a chronic inflammatory process. The incidence of periodontitis in cardiac patients with atherosclerosis is a well-established fact. The role of viruses in the etiopathogenesis of both has been proposed.

AIM

The aim of the study was to evaluate the prevalence of Torque Teno virus (TTV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) in cardiac patients with atherosclerosis and coexisting chronic periodontitis (CP).

MATERIALS AND METHODS

Thirty patients (17 males and 13 females) with atherosclerotic plaques and coexisting periodontitis were recruited for this cross-sectional study. Viral DNA was extracted from the subgingival and atheromatous plaque. The presence of CMV, EBV, and TTV in the plaque samples was identified using polymerase chain reaction. The collected data were statistically analyzed for the prevalence of the viruses and Chi-squared test was performed to find out its association with atheroma and CP.

RESULTS

The prevalence of CMV, EBV, and TTV in atheromatous plaque was 63.3%, 56.7%, and 46.7%, respectively, as compared to rates of 80%, 63.3%, and 53.3% in subgingival plaque. Results also indicated no significant association of CMV, EBV, and TTV in both samples (P = 0.08, 0.346, and 0.261, respectively).

CONCLUSIONS

There was no significant association of CMV, EBV, and TTV between subgingival and atheromatous plaque. The prevalence of CMV, EBV, and TTV was high in atheromatous plaque. TTV was isolated from more than 50% of participants in atheromatous plaque, which is a significant finding.

Demographics of Head and Neck Cancer Patients: A Single Institution Experience

Introduction Head and neck cancer (HNC) comprises a diverse group of oncological entities, originating from various tissue types and organ localizations, situated in the topographical regions of the head and neck (H&N). This single institution retrospective study was aimed at establishing the HNC patient demographics and categorizing the individual incidence of H&N malignancies, regarding their organ of origin and main histopathological type. Materials and methods All histologically verified cases of HNC from a single tertiary referral center were reviewed in a descriptive retrospective manner. Data sampling period was 47 months. Results Male to female ratio of the registered HNC cases was 3.24:1. The mean age of diagnosis was 63.84 ± 12.65 years, median 65 years. The most common HNC locations include the larynx 30.37% (n = 188), lips and oral cavity 29.08% (n = 180), pharynx 20.03% (n = 124) and salivary glands 10.94% (n = 68), with other locations such as the external nose, nasal cavity and sinuses and auricle and external ear canal harboring a minority of the cases. The main histopathological groups include squamous cell carcinoma 76.74% (n = 475) and adenocarcinoma 6.14% (n = 38), with other malignant entries such as other epithelial malignancies, primary tonsillar, mucosa-associated lymphoid tissue or parenchymal lymphomas, connective tissue neoplasias, neuroendocrine and vascular malignancies diagnosed in a minority of cases. Conclusion Considered to be relatively rare, HNC represents a diverse group of oncological entities with individual and specific demographic characteristics. The reported single institution results appear representative of the national incidence and characteristics of HNC.

Saliva and viral infections

Over the last 10 years there have been only a handful of publications dealing with the oral virome, which is in contrast to the oral microbiome, an area that has seen considerable interest. Here, we survey viral infections in general and then focus on those viruses that are found in and/or are transmitted via the oral cavity; norovirus, rabies, human papillomavirus, Epstein‐Barr virus, herpes simplex viruses, hepatitis C virus, and HIV. Increasingly, viral infections have been diagnosed using an oral sample (e.g. saliva mucosal transudate or an oral swab) instead of blood or urine. The results of two studies using a rapid and semi‐quantitative lateral flow assay format demonstrating the correlation of HIV anti‐IgG/sIgA detection with saliva and serum samples are presented. When immediate detection of infection is important, point‐of‐care devices that obtain a non‐invasive sample from the oral cavity can be used to provide a first line diagnosis to assist in determining appropriate counselling and therapeutic path for an increasing number of diseases.

Oral hairy leukoplakia arising in a patient with hairy cell leukaemia: the first reported case

Oral hairy leukoplakia (OHL) is an oral mucosal lesion that is associated with Epstein-Barr virus infection. It commonly presents as an asymptomatic, non-removable white patch on the lateral borders of the tongue in individuals who are immunocompromised. Historically, OHL was thought to be pathognomonic of HIV infection; however, it is now an established phenomenon in a range of conditions affecting immune competence. Hairy cell leukaemia (HCL) is a rare chronic B cell lymphoproliferative disease named after the distinctive cytology of the atypical cells. We report the first case of OHL arising in an individual with HCL that resolved following remission of the haematological malignancy.

Epstein-Barr virus (EBV)-associated epithelial and non-epithelial lesions of the oral cavity

Epstein–Barr virus (EBV) is known to be associated with the development of malignant lymphoma and lymphoproliferative disorders (LPDs) in immunocompromised patients. EBV, a B-lymphotropic gamma-herpesvirus, causes infectious mononucleosis and oral hairy leukoplakia, as well as various pathological types of lymphoid malignancy. Furthermore, EBV is associated with epithelial malignancies such as nasopharyngeal carcinoma (NPC), salivary gland tumor, gastric carcinoma and breast carcinoma. In terms of oral disease, there have been several reports of EBV-related oral squamous cell carcinoma (OSCC) worldwide. However, the role of EBV in tumorigenesis of human oral epithelial or lymphoid tissue is unclear. This review summarizes EBV-related epithelial and non-epithelial tumors or tumor-like lesions of the oral cavity. In addition, we describe EBV latent genes and their expression in normal epithelium, inflamed gingiva, epithelial dysplasia and SCC, as well as considering LPDs (MTX- and age-related) and DLBCLs of the oral cavity.

The emerging roles of B cells as partners and targets in periodontitis

Initial studies of periodontal disease suggested that T cell-mediated immunity against oral Gram-negative microorganisms is a key player in the pathogenesis of this inflammatory disease. Recent investigations, however, revealed that B cells are also engaged. Given their chief role in innate-like and adaptive immune responses, B cells could exert protective functions in periodontitis. However, the periodontal bacteria-specific antibody response is generally unable to halt disease progression in affected subjects, suggesting that the antibodies produced could exhibit low anti-bacterial blocking functions or opsonophagocytic potential, and/or unfavorable effects. Moreover, although microbial antigens are involved in the induction of the inflammatory responses in human adult periodontitis, endogenous antigens also may contribute to the chronicity of this common disease. Not only antibodies to self-antigens, such as collagen, are locally produced, but the autoreactivities observed in aggressive periodontitis are more severe and diverse than those observed in chronic periodontitis, suggesting that autoimmune reactivity could play a role in the tissue destruction of periodontal disease. Further support for a pathological role of B cells in periodontitis comes from the finding that B cell-deficient mice are protected from bacterial infection-induced alveolar bone loss. Studies in patients indicate that B cells and plasma cells, together with osteoclastogenic factors (RANKL and osteoprotegerin) and specific cytokines involved in their growth and differentiation (BAFF and APRIL) participate in the induction of the pathological bone loss in periodontitis. This novel insight suggests that selective targeting of B cells could represent a future therapeutic avenue for severe periodontal disease.

Oral Hygiene and Risk of Nasopharyngeal Carcinoma-A Population-Based Case-Control Study in China

BACKGROUND

The association between oral health and risk of nasopharyngeal carcinoma (NPC) is largely unknown. Further understanding could shed light on potential pathogenic mechanisms and preventive measures.

METHODS

We conducted a population-based case-control study in southern China between 2010 and 2014. We enrolled 2,528 incident NPC cases, aged 20-74 years, and 2,596 controls, randomly selected from the total population registers, with frequency matching to the 5-year age and sex distribution of the cases by geographic region. We interviewed subjects using a structured questionnaire inquiring about oral health indicators and potential confounding factors. We used unconditional logistic regression to estimate multivariate-adjusted ORs with 95% confidence intervals (CI).

RESULTS

A higher number of filled teeth was associated with an elevated risk of NPC. Individuals with 1 to 3 and more than 3 teeth filled versus none had adjusted ORs of 1.25 (95% CI, 1.06-1.49) and 1.55 (95% CI, 1.13-2.12), respectively (Ptrend = 0.002). Conversely, the adjusted OR for those who brushed teeth twice or more per day versus once or less per day was 0.62 (95% CI, 0.55-0.70). We detected a borderline significant positive association with earlier age at first adult tooth loss.

CONCLUSION

Our study suggested a positive association between some indicators of poor oral health and risk of NPC. Further studies are needed to confirm whether the findings are causal and, if so, to further explain the underlying mechanisms.

IMPACT

Improvement of oral hygiene might contribute to reducing NPC risk. Cancer Epidemiol Biomarkers Prev; 25(8); 1201-7. ©2016 AACR.

Human Papilloma virus in Juvenile Nasopharyngeal Angiofibroma: possible recent trend

BACKGROUND

Juvenile nasopharyngeal angiofibroma (JNA) has witnessed a four-fold increase in the incidence at our facility in the current decade as compared to the 1980s. With high global incidence of human pappilloma virus (HPV) related oropharyngeal cancer in India, we hypothesize its implication in JNA as it has not yet been reported.

METHODS

Clinico-Surgical variables of 6 patients of JNA were included for correlation and their tissue samples were subjected to western blotting (WB), polymerase chain reaction and immunoflorescence to demonstrate a definite association with HPV. In addition 6 control samples (adenoids) underwent WB analysis.

OBSERVATIONS

A universal presence of HPV with JNA is novel 'discovery' and has suggested a possibility of a definite association. Only a single case suggested weak infection. None of the controls suggested infection, thus ruling out the presence of HPV in nasopharynx of normal population.

INTERPRETATION

With the dawn of this definite association, no specific conclusions can yet be drawn but a whole plethora of questions have emerged with our novel 'discovery'.

Epstein-Barr Virus and Its Association with Oral Hairy Leukoplakia: A Short Review

In immunocompromised subjects, Epstein-Barr virus (EBV) infection of terminally differentiated oral keratinocytes may result in subclinical productive infection of the virus in the stratum spinosum and in the stratum granulosum with shedding of infectious virions into the oral fluid in the desquamating cells. In a minority of cases this productive infection with dysregulation of the cell cycle of terminally differentiated epithelial cells may manifest as oral hairy leukoplakia. This is a white, hyperkeratotic, benign lesion of low morbidity, affecting primarily the lateral border of the tongue. Factors that determine whether productive EBV replication within the oral epithelium will cause oral hairy leukoplakia include the fitness of local immune responses, the profile of EBV gene expression, and local environmental factors.

Prevalence of salivary Epstein-Barr virus in potentially malignant oral disorders and oral squamous cell carcinoma

Background

To analyze the presence of salivary Epstein-Barr virus (EBV) DNA in oral squamous cell carcinoma and potentially malignant oral disorders.

Material and Methods

Three groups were studied: Group 1 (12 oral squamous cell carcinomas (OSCC)), Group 2 (12 potentially malignant oral disorders (PMD)) and Group 3 (47 healthy controls). EBV DNA salivary analysis was performed by PCR.

Results

The highest percentage of positive salivary EBV DNA corresponded to the OSCC group (58.3%), followed by the PMD group (41.7%) and the controls (40.4%). The differences between groups were not statistically significant, however (p>0.05).

Conclusions

Salivary EBV DNA was more prevalent in OSCC than in PMD or the controls.

Key words:EBV DNA, saliva, oral squamous cell carcinoma, oral leukoplakia.

Detection of Epstein-Barr virus in different sources of materials from patients with oral lichen planus: a case-control study

AIMS

To detect the presence of Epstein-Barr virus (EBV) DNA in different sources of materials from a matched group of patients with oral lichen planus (OLP) and a group of people without OLP lesions, and to correlate the presence of virus with epidemiological variables of the groups studied.

METHODS

Fresh tissue samples, saliva, exfoliated cells and plasma of 24 patients with OLP lesions (cases) and 17 patients without OLP lesions (controls) were collected. EBV was detected by nested PCR.

RESULTS

Viral positivity was obtained in 62.5% of tissue samples; in 70.8% of exfoliated cell samples; in 33.3% of blood plasma samples and in 75% of saliva samples in the cases; and in 35.3% of tissue samples; 82.4% of exfoliated cell samples; in 47.1% of blood plasma samples and in 64.7% of saliva samples in the controls. There was a predominance of women in both groups. Variables not atrophic-erosive were most affected by EBV.

CONCLUSIONS

No relationship between EBV and OLP was found. However, all sources tested in this study were considered suitable for the detection of viruses.

Prevalence of Human papillomavirus (HPV) and Epstein-Barr virus (EBV) in oral and oropharyngeal squamous cell carcinoma in south-eastern Poland

OBJECTIVE

The aim of this study was to analyze the prevalence of HPV and EBV in oral and oropharyngeal squamous cell carcinoma in south-eastern Poland. The correlation between viral infection, OSCC, alcohol use, tobacco smoking, demographic data (gender, age, place of residence), anatomic location, pre-treatment staging, evidence of metastases to lymph nodes, and grading was also investigated.

METHODS

The examination samples were collected from paraffin tissue blocks, from 154 patients. Viral DNA was amplified by the nested-PCR method.

RESULTS

HPV DNA was detected in 29.2 % of the tested samples (in 27.4 % of oropharyngeal and in 30.4 % of oral cavity). The HPV type 16 was detected in 15.6 % of all samples, and in 53.3 % of HPV-positive group. In HPV-positive samples from oropharyngeal HPV 16 constitute 76.5 %, and in HPV-positive samples from oral cavity HPV 16 constitute 39.3 %. Mixed infection (more than one type of HPV) was observed in 23.5 and 60.7 %, respectively, and in 46.7 % of all HPV-positive samples, and in 12.3 % of the whole study group. EBV DNA was detected in 27.3 % of the cases and HPV-EBV co-infection in 7.8 % of samples.

CONCLUSIONS

In major patients from Southeastern region of Poland with oropharyngeal cancer HPV type 16 was detected but in oral cavity cancer other mixed infections were observed (i.e. 51, 52, 59, 66, 68, 71, 74). HPV 16 was detected more often among patients younger than 50 years of age, whereas the mixed HPV in the group aged 50-59. The pathogenesis of oral squamous cell carcinoma may be connected with EBV infection. Future studies on the mechanisms of HPV/EBV co-infection and/or superinfection and their role in oral squamous cell carcinoma are necessary.

Twenty-first-century oral hairy leukoplakia--a non-HIV-associated entity

OBJECTIVE

This study presents the clinicopathologic features of a series (N = 35) of patients with non-human immunodeficiency virus (HIV)-associated oral hairy leukoplakia (OHL).

METHODS

Patients with non-HIV-associated OHL were identified from three centers. Epstein-Barr virus infection was demonstrated by using EBV early ribonucleic acid in situ hybridization. The presence of Candida co-infection was evaluated by diastase periodic acid-Schiff staining. The clinical features were determined by review of the medical records.

RESULTS

Twenty-eight patients had intercurrent respiratory problems requiring long-term steroid inhaler use, four suffered from autoimmune diseases requiring immunosuppressant therapy, and four had diabetes. The majority of lesions were located on the tongue, and 24 showed evidence of Candida co-infection.

CONCLUSIONS

In the twenty-first century, the presence of OHL should not be regarded as pathognomic for HIV infection or significant systemic immunosuppression. Local and systemic immunosuppression, in the form of steroid inhaler use, is a risk factor for the development of OHL.

Prevalence and quantitative analysis of Epstein-Barr virus DNA and Porphyromonas gingivalis associated with Japanese chronic periodontitis patients

Objective

A number of studies have recently suggested Epstein–Barr virus (EBV) involvement in the pathogenesis of periodontitis. In this study, we investigated the association between major periodontopathic bacteria Porphyromonas gingivalis (P. gingivalis) and EBV in Japanese chronic periodontitis (CP) patients.

Materials and methods

A group of 25 patients with CP participated in the study along with 13 individuals without periodontitis. Subgingival samples were obtained with paper points. Quantitative real-time polymerase chain reaction (PCR) was used to detect EBV DNA and P. gingivalis.

Results

In the CP patients, EBV DNA and P. gingivalis were detected in both 80 % of sites with probing pocket depths (PPD) of ≥5 mm and in 40 and 36 % of sites with PPD ≤3 mm, respectively. EBV DNA and P. gingivalis were detected in 50 and 27 % of the sites in periodontally healthy individuals. Coexistence of EBV DNA and P. gingivalis was significantly higher in the deeper PPD sites of CP patients (68 %) than in the PPD sites of the healthy controls (15 %) and shallow PPD sites of CP patients (12 %). PCR-positive deeper PPD sites of CP patients for EBV DNA and P. gingivalis range between 3.74 × 10³∼2.83 × 10⁹ and 2.73 × 10⁵∼6.65 × 10⁹ (copies/ml), respectively.

Conclusion

These results suggest an association between EBV DNA, P. gingivalis, and CP in Japanese individuals. Further studies are required to clarify this association; however, we believe that our enhanced understanding of the pathogenesis of periodontal diseases involving viral infections will lead to new treatments.

Significant role of macrophages in human cancers associated with Epstein-Barr virus (Review)

Epstein-Barr virus (EBV) is a ubiquitous pathogen that was first identified as a human cancer virus. Many human cancers are associated with EBV, and we demonstrated that EBV infects macrophages. Macrophages infected with EBV show a close correlation with many human cancers, and thus more attention must be given to the role of macrophages infiltrating into cancer tissues associated with EBV. In this review, I discuss the role of macrophages in the process of EBV-associated oncogenesis with regard to interleukin-10.

Lessons learned and unlearned in periodontal microbiology

Periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation elicited by specific subgingival species. In the past few decades, efforts to understand the periodontal microbiota have led to an exponential increase in information about biofilms associated with periodontal health and disease. In fact, the oral microbiota is one of the best-characterized microbiomes that colonize the human body. Despite this increased knowledge, one has to ask if our fundamental concepts of the etiology and pathogenesis of periodontal diseases have really changed. In this article we will review how our comprehension of the structure and function of the subgingival microbiota has evolved over the years in search of lessons learned and unlearned in periodontal microbiology. More specifically, this review focuses on: (i) how the data obtained through molecular techniques have impacted our knowledge of the etiology of periodontal infections; (ii) the potential role of viruses in the etiopathogenesis of periodontal diseases; (iii) how concepts of microbial ecology have expanded our understanding of host-microbe interactions that might lead to periodontal diseases; (iv) the role of inflammation in the pathogenesis of periodontal diseases; and (v) the impact of these evolving concepts on therapeutic and preventive strategies to periodontal infections. We will conclude by reviewing how novel systems-biology approaches promise to unravel new details of the pathogenesis of periodontal diseases and hopefully lead to a better understanding of their mechanisms.

EBV infection is common in gingival epithelial cells of the periodontium and worsens during chronic periodontitis

An amplifying role for oral epithelial cells (ECs) in Epstein-Barr Virus (EBV) infection has been postulated to explain oral viral shedding. However, while lytic or latent EBV infections of oro/nasopharyngeal ECs are commonly detected under pathological conditions, detection of EBV-infected ECs in healthy conditions is very rare. In this study, a simple non-surgical tissue sampling procedure was used to investigate EBV infection in the periodontal epithelium that surrounds and attaches teeth to the gingiva. Surprisingly, we observed that the gingival ECs of the periodontium (pECs) are commonly infected with EBV and may serve as an important oral reservoir of latently EBV-infected cells. We also found that the basal level of epithelial EBV-infection is significantly increased in chronic periodontitis, a common inflammatory disease that undermines the integrity of tooth-supporting tissues. Moreover, the level of EBV infection was found to correlate with disease severity. In inflamed tissues, EBV-infected pECs appear to be prone to apoptosis and to produce larger amounts of CCL20, a pivotal inflammatory chemokine that controls tissue infiltration by immune cells. Our discovery that the periodontal epithelium is a major site of latent EBV infection sheds a new light on EBV persistence in healthy carriers and on the role of this ubiquitous virus in periodontitis. Moreover, the identification of this easily accessible site of latent infection may encourage new approaches to investigate and monitor other EBV-associated disorders.

Higher prevalence of Epstein-Barr virus DNA in deeper periodontal pockets of chronic periodontitis in Japanese patients

Periodontitis, a complex chronic inflammatory disease caused by subgingival infection, is among the most prevalent microbial diseases in humans. Although traditional microbiological research on periodontitis has focused on putative bacteria such as Porphyromonas gingivalis, the herpes virus is proposed to be involved in the pathogenesis of periodontitis because bacterial etiology alone does not adequately explain various clinical aspects. In this study, we established for the first time, more Epstein–Barr virus (EBV) DNA is found deeper in periodontal pockets of chronic periodontitis in Japanese patients. Subgingival samples were collected from 85 patients with chronic periodontitis having two periodontal sites with probing depths (PD) of ≤3 mm (shallow) or ≥5 mm (deep) and were subjected to a nested polymerase chain reaction. EBV DNA was more frequently detected in patients with deeper PD sites (66%) than in those with shallow PD sites (48%) or healthy controls (45%). Coexistence of EBV DNA and P. gingivalis was significantly higher in patients with deeper PD sites (40%) than in those with shallow PD sites (14%) or healthy controls (13%). Although no difference in clinical index for periodontitis, the odds ratio of EBV DNA in patients with deeper PD sites was 2.36, which was 2.07-fold higher than that in those with shallow PD sites. Interestingly, the odds of acquiring chronic periodontitis (PD ≥5 mm) were higher in the presence of both EBV DNA and P. gingivalis compared with either EBV DNA or P. gingivalis only. In addition, we also observed that EBV-encoded small RNA (EBER) in positive cells of human gingival tissues. These results would suggest that EBV DNA may serve as a pathogenic factor leading to chronic periodontitis among Japanese patients.

Low-cost periodontal therapy

Periodontitis is a complex infectious disease that affects low-income individuals disproportionately. Periodontitis is associated with specific bacterial species and herpesviruses, and successful prevention and treatment of the disease is contingent upon effective control of these pathogens. This article presents an efficacious, highly safe, minimally invasive, practical and low-cost periodontal therapy that involves professional and patient-administered mechanical therapy and antimicrobial agents. The major components are scaling for calculus removal, periodontal pocket irrigation with potent antiseptics, and treatment with systemic antibiotics for advanced disease. Povidone-iodine and sodium hypochlorite have all the characteristics for becoming the first-choice antiseptics in the management of periodontal diseases. Both agents show excellent antibacterial and antiviral properties, are readily available throughout the world, have been safely used in periodontal therapy for decades, offer significant benefits for individuals with very limited financial resources, and are well accepted by most dental professionals and patients. Four per cent chlorhexidine applied with a toothbrush to the most posterior part to the tongue dorsum can markedly reduce or eliminate halitosis in most individuals. Systemic antibiotics are used to treat periodontopathic bacteria that are not readily reached by topical therapy, such as pathogens within gingival tissue, within furcation defects, at the base of periodontal pockets, and on the tongue, tonsils and buccal mucosae. Valuable antibiotic therapies are amoxicillin-metronidazole (250 mg of amoxicillin and 250 mg of metronidazole, three times daily for 8 days) for young and middle-aged patients, and ciprofloxacin-metronidazole (500 mg of each, twice daily for 8 days) for elderly patients and for patients in developing countries who frequently harbor enteric rods subgingivally. Scaling to remove dental calculus and the prudent use of inexpensive antimicrobial agents can significantly retard or arrest progressive periodontitis in the great majority of patients.

A novel gammaherpesvirus found in oral squamous cell carcinomas in sun bears (Helarctos malayanus)

A novel herpesvirus was detected in sun bears ( Helarctos malayanus) with oral squamous cell carcinoma. Five captive sun bears from 4 institutions in the United States presented with oral lesions ranging from erythema and mild erosions to nodular, ulcerated masses. All 5 were diagnosed with squamous cell carcinoma. The tumors were treated with surgical resection but recurrence, local extension, or appearance of new lesions was noted in all cases. Intralesional chemotherapy was administered in 2 cases, and the nonsteroidal anti-inflammatory drug piroxicam was administered in 3 cases. Virus was detected in 4 of the 5 bears’ tissue samples using a consensus herpesvirus polymerase chain reaction. Nucleotide sequencing and phylogenetic analysis showed that this herpesvirus is in the subfamily Gammaherpesvirinae and distinct from other known herpesviruses. The association between the herpesvirus and squamous cell carcinoma is unknown. The current study presents a novel gammaherpesvirus within the order Ursidae, with the name Ursid herpesvirus 1 proposed.