Herpesviruses 6, 7 and 8 in HIV- and non-HIV-associated periodontitis

TLR4/7-mediated host-defense responses of gingival epithelial cells

Gingival epithelial cells (GECs) are physical and immunological barriers against outward pathogens while coping with a plethora of non-pathogenic commensal bacteria. GECs express several members of Toll-like receptors (TLRs) and control subsequent innate immune responses. TLR4 senses lipopolysaccharide (LPS) while TLR7/8 recognizes single-strand RNA (ssRNA) playing important roles against viral infection. However, their distinct roles in GECs have not been fully demonstrated. Here, we analyzed biological responses of GECs to  LPS and CL075, a TLR7/8 agonist. GE1, a mouse gingival epithelial cell line, constitutively express TLR4 and TLR7, but not TLR8, like primary skin keratinocytes. Stimulation of GE1 cells with CL075 induced cytokine, chemokine, and antimicrobial peptide  expressions, the pattern of which is rather different from that with LPS: higher mRNA levels of interferon (IFN) β, CXCL10, and β-defensin (BD) 14 (mouse homolog of human BD3); lower levels of tumor necrosis factor (TNF), CCL5, CCL11, CCL20, CXCL2, and CX3CL1. As for the intracellular signal transduction of GE1 cells, CL075 rapidly induced significant AKT phosphorylation but failed to activate IKKα/β-NFκB pathway, whereas LPS induced marked IKKα/β-NFκB activation without significant AKT phosphorylation. In contrast, both CL075 and LPS induced rapid IKKα/β-NFκB activation and AKT phosphorylation in a macrophage cell line. Furthermore, specific inhibition of AKT activity abrogated CL075-induced IFNβ, CXCL10, and BD14 mRNA expression in GE1 cells. Thus, TLR4/7 ligands appear to induce rather different host-defense responses of GECs through distinct intracellular signaling mechanisms.

Detection of Human Herpesviruses in Sera and Saliva of Asymptomatic HIV-Infected Individuals Using Multiplex RT-PCR DNA Microarray

Human herpesviruses (HHVs) are frequently linked to an increased risk of acquiring human immunodeficiency virus (HIV), and vice versa. This study aimed to detect human herpesvirus (HHV) members in the sera and saliva of asymptomatic HIV-infected individuals. Paired saliva and serum samples were obtained from 30 asymptomatic HIV-infected individuals. HHVs were detected with a multiplex reverse transcription-polymerase chain reaction (RT-PCR) DNA microarray Clart®Entherpex kit. A total of 30 subjects were enrolled: 23 (76.67%) men and 7 (23.33%) women. The present study showed that at least one or more HHV members were detected in the saliva and sera of all (100%) of the subjects. In the saliva, we detected herpes simplex virus 1 (HSV-1) 6.67%, herpes simplex virus 2 (HSV-2) 6.67%, Epstein-Barr virus (EBV) 86.67%, cytomegalovirus (CMV) 63.33%, HHV-6 (40%), and HHV-7 (83.33%). In the sera, HSV-2 (20%), EBV (30%), CMV (40%), HHV-6 (0%), and HHV-7 (76.67%) were found, but not HSV-1. VZV and HHV-8 were not detected in either the saliva or sera. EBV and HHV6 were significantly more prevalent in the saliva than they were in the sera of asymptomatic HIV-infected individuals (p < 0.05). However, no significant differences were found in the prevalence of HSV-1, EBV, CMV, HHV-6, and HHV-7 in the saliva and sera of asymptomatic HIV-infected individuals (p > 0.05). In conclusion, the multiplex RT-PCR DNA microarray can serve as a valuable diagnostic tool that can be used as a screening tool or a first-line test for HHVs infections.

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.

Subgingival fungi, Archaea, and viruses under the omics loupe

The microbial communities that inhabit the gingival crevice are responsible for the pathological processes that affect the periodontium. The changes in composition and function of subgingival bacteria as disease develops have been extensively studied. Subgingival communities, however, also contain fungi, Archaea, and viruses, which could contribute to the dysbiotic processes associated with periodontal diseases. High-throughput DNA sequencing has facilitated a better understanding of the mycobiome, archaeome, and virome. However, the number of studies available on the nonbacterial components of the subgingival microbiome remains limited in comparison with publications focusing on bacteria. Difficulties in characterizing fungal, archaeal, and viral populations arise from the small portion of the total metagenome mass they occupy and lack of comprehensive reference genome databases. In addition, specialized approaches potentially introducing bias are required to enrich for viral particles, while harsh methods of cell lysis are needed to recover nuclei acids from certain fungi. While the characterization of the subgingival diversity of fungi, Archaea and viruses is incomplete, emerging evidence suggests that they could contribute in different ways to subgingival dysbiosis. Certain fungi, such as Candida albicans are suggested to facilitate colonization of bacterial pathogens. Methanogenic Archaea are associated with periodontitis severity and are thought to partner synergistically with bacterial fermenters, while viruses may affect immune responses or shape microbial communities in ways incompletely understood. This review describes the manner in which omics approaches have improved our understanding of the diversity of fungi, Archaea, and viruses within subgingival communities. Further characterization of these understudied components of the subgingival microbiome is required, together with mechanistic studies to unravel their ecological role and potential contributions to dysbiosis.

Proteome Analysis of Molecular Events in Oral Pathogenesis and Virus: A Review with a Particular Focus on Periodontitis

Some systemic diseases are unquestionably related to periodontal health, as periodontal disease can be an extension or manifestation of the primary disease process. One example is spontaneous gingival bleeding, resulting from anticoagulant treatment for cardiac diseases. One important aspect of periodontal therapy is the care of patients with poorly controlled disease who require surgery, such as patients with uncontrolled diabetes. We reviewed research on biomarkers and molecular events for various diseases, as well as candidate markers of periodontal disease. Content of this review: (1) Introduction, (2) Periodontal disease, (3) Bacterial and viral pathogens associated with periodontal disease, (4) Stem cells in periodontal tissue, (5) Clinical applications of mass spectrometry using MALDI-TOF-MS and LC-MS/MS-based proteomic analyses, (6) Proteome analysis of molecular events in oral pathogenesis of virus in GCF, saliva, and other oral Components in periodontal disease, (7) Outlook for the future and (8) Conclusions. This review discusses proteome analysis of molecular events in the pathogenesis of oral diseases and viruses, and has a particular focus on periodontitis.

Current trends and new developments in HIV research and periodontal diseases

With the advent of combined antiretroviral therapies, the face of HIV infection has changed dramatically from a disease with almost certain mortality from serious comorbidities, to a manageable chronic condition with an extended lifespan. In this paper we present the more recent investigations into the epidemiology, microbiology, and pathogenesis of periodontal diseases in patients with HIV, and the effects of combined antiretroviral therapies on the incidence and progression of these diseases both in adults and perinatally infected children. In addition, comparisons and potential interactions between the HIV-associated microbiome, host responses, and pathogenesis in the oral cavity with the gastrointestinal tract and other areas of the body are presented. Also, the effects of HIV and combined antiretroviral therapies on comorbidities such as hyposalivation, dementia, and osteoporosis on periodontal disease progression are discussed.

Association of interferon lambda-1 with herpes simplex viruses-1 and -2, Epstein-Barr virus, and human cytomegalovirus in chronic periodontitis

AIM

Periodontal tissues facilitate the homing of herpes viruses that elicit the immune-inflammatory response releasing the interferons (IFN). IFN lambda-1 (λ1) can suppress the replication of viruses, and induces the antiviral mechanism. The aim of the present study was to evaluate the association between IFN-λ1 and periodontal herpes viruses in the immunoregulation of chronic periodontal disease.

METHODS

The cross-sectional study design included 30 chronic periodontitis patients with a mean age of 42.30 ± 8.63 years. Gingival crevicular fluid collected was assessed for IFN-λ1 using enzyme-linked immunosorbent assay and four herpes viruses were detected using multiplex polymerase chain reaction technique. IFN-λ1 levels were compared between virus-positive and -negative patients for individual and total viruses.

RESULTS

Fifty per cent (n = 15) of patients were positive for the four herpes viruses together; 50% (n = 15), 30% (n = 9), 26.7% (n = 8), and 40% (n = 12) were positive for herpes simplex virus (HSV)-1, Epstein-Barr virus, HSV-2, and human cytomegalovirus, respectively. The mean concentrations of IFN-λ1 in virus-positive patients (14.38 ± 13.95) were lower than those of virus-negative patients (228.26 ± 215.35). INF-λ1 levels in individual virus groups were also lower in virus-positive patients compared to virus-negative patients, with P < 0.001.

CONCLUSIONS

These results suggest that IFN-λ1 could have antiviral and therapeutic value against the viruses in the pathogenesis of chronic periodontitis.

(B2) Periodontal Diseases and Other Bacterial Infections

The workshop addressed the following questions with respect to periodontal diseases and bacterial infections seen in HIV infection: (1) What is linear gingival erythema? Is it prevalent only in HIV disease? A crude Delphi technique was used to ascertain whether LGE existed, but a consensus could not be reached. It was agreed that a diagnosis of LGE should be considered only if the lesion persists after removal of plaque in the initial visit. (2) Do periodontal pockets contribute to viremia in HIV infection? At present, the data are not available to answer this question. (3) Do anti-viral drugs reach the sulcular fluid in significant concentrations? No one at the workshop was aware of data that could answer this question. (4) Does concurrent tuberculosis infection modify the oral manifestations of HIV infection? Though analysis of data from the developing countries does suggest an association between tuberculosis and oral candidiasis, more data and multivariate analysis considering immunosuppression as a confounding factor are necessary, for any conclusions to be derived. (5) What pathogens are involved in periodontal diseases in HIV infection? Periodontal disease may be initiated by conventional periodontal pathogens. But the progression and tissue destruction depend upon the presence of typical and atypical micro-organisms, including viruses, their by-products, increased secretion of potentially destructive inflammatory mediators, and overwhelming host response. (6) How can we diagnose the diseases seen in HIV infection? The answer can be obtained only with data from controlled and blinded studies. It is necessary to design collaborative multi-center longitudinal studies. The results obtained from such large sample sizes can contribute eventually to interpretation of the outcome.

LACK OF ASSOCIATION BETWEEN HERPESVIRUS DETECTION IN SALIVA AND GINGIVITIS IN HIV‑INFECTED CHILDREN

The aims of this study were to compare the detection of human herpesviruses (HHVs) in the saliva of HIV-infected and healthy control children, and to evaluate associations between viral infection and gingivitis and immunodeficiency. Saliva samples were collected from 48 HIV-infected and 48 healthy control children. Clinical and laboratory data were collected during dental visits and from medical records. A trained dentist determined gingival indices and extension of gingivitis. Saliva samples were tested for herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) by nested polymerase chain reaction assays. Thirty-five HIV-infected and 16 control children had gingivitis. Seventeen (35.4%) HIV-infected children and 13 (27%) control children were positive for HHVs. CMV was the most commonly detected HHV in both groups (HIV-infected, 25%; control, 12.5%), followed by HSV-1 (6.2% in both groups) and HSV-2 (HIV-infected, 4.2%; control, 8.3%). The presence of HHVs in saliva was not associated with the presence of gingivitis in HIV-1-infected children (p = 0.104) or healthy control children (p = 0.251), or with immunosuppression in HIV-infected individuals (p = 0.447). Gingivitis was correlated with HIV infection (p = 0.0001). These results suggest that asymptomatic salivary detection of HHVs is common in HIV-infected and healthy children, and that it is not associated with gingivitis.

Quantification of Epstein-Barr Virus and Human Cytomegalovirus in Chronic Periodontal Patients

Background:

Although studies focused mainly on the identification of periopathogenic bacteria, recent reports have suggested that various herpes viruses may also be involved in the occurrence and progression of different forms of periodontal diseases.

Objectives:

This study aimed to compare the prevalence and load of Epstein-Barr Virus (EBV) and Human Cytomegalovirus (HCMV) in subgingival tissue specimens between chronic periodontitis and healthy sites.

Patients and Methods:

A total of 60 samples from the systematically healthy patients with chronic periodontitis participated in this study (mean age, 35 ± 7). Clinical periodontal evaluation included the plaque index (PI) (Loe and Silness), bleeding on probing (BOP) (O’Leary), bleeding index, periodontal pocket depth (PPD) and clinical attachment level measurement. Tissue specimens harvested from > 6 mm periodontal pockets and from ≤ 3 mm sulcus depth in a quadrant of the same patient using periodontal curettes. Moreover, the unstimulated whole saliva was gathered as a shedding medium. A Taq-man Real-Time Polymerase Chain Reaction assay was used to identify genomic copies of periodontal HCMV and EBV. Data were analyzed by the Wilcoxon-signed ranks and Friedman tests using the SPSS 16 software.

Results:

Out of 60 samples of subgingival tissues taken from the patients with chronic periodontitis, EBV count was the highest in saliva and the least in the tissue sample with PD < 3 mm (P < 0.05). The highest HCMV count was in saliva and tissue samples with PD > 6 mm (P < 0.05).

Conclusions:

According to the results of this study, quantification of HCMV and EBV observed in this study is high in periodontal tissue samples of severe chronic periodontitis.

Activation and repression of Epstein-Barr Virus and Kaposi's sarcoma-associated herpesvirus lytic cycles by short- and medium-chain fatty acids

The lytic cycles of Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are induced in cell culture by sodium butyrate (NaB), a short-chain fatty acid (SCFA) histone deacetylase (HDAC) inhibitor. Valproic acid (VPA), another SCFA and an HDAC inhibitor, induces the lytic cycle of KSHV but blocks EBV lytic reactivation. To explore the hypothesis that structural differences between NaB and VPA account for their functional effects on the two related viruses, we investigated the capacity of 16 structurally related short- and medium-chain fatty acids to promote or prevent lytic cycle reactivation. SCFAs differentially affected EBV and KSHV reactivation. KSHV was reactivated by all SCFAs that are HDAC inhibitors, including phenylbutyrate. However, several fatty acid HDAC inhibitors, such as isobutyrate and phenylbutyrate, did not reactivate EBV. Reactivation of KSHV lytic transcripts could not be blocked completely by any fatty acid tested. In contrast, several medium-chain fatty acids inhibited lytic activation of EBV. Fatty acids that blocked EBV reactivation were more lipophilic than those that activated EBV. VPA blocked activation of the BZLF1 promoter by NaB but did not block the transcriptional function of ZEBRA. VPA also blocked activation of the DNA damage response that accompanies EBV lytic cycle activation. Properties of SCFAs in addition to their effects on chromatin are likely to explain activation or repression of EBV. We concluded that fatty acids stimulate the two related human gammaherpesviruses to enter the lytic cycle through different pathways. Importance: Lytic reactivation of EBV and KSHV is needed for persistence of these viruses and plays a role in carcinogenesis. Our direct comparison highlights the mechanistic differences in lytic reactivation between related human oncogenic gammaherpesviruses. Our findings have therapeutic implications, as fatty acids are found in the diet and produced by the human microbiota. Small-molecule inducers of the lytic cycle are desired for oncolytic therapy. Inhibition of viral reactivation, alternatively, may prove useful in cancer treatment. Overall, our findings contribute to the understanding of pathways that control the latent-to-lytic switch and identify naturally occurring molecules that may regulate this process.

Current status of herpesvirus identification in the oral cavity of HIV-infected children

INTRODUCTION

Some viruses of the Herpesviridae family are frequently the etiologic agents of oral lesions associated with HIV. The aim of this study was to identify the presence of herpes simplex virus types 1 and 2 (HSV-1, HSV-2), Varicella Zoster virus (VZV), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus type 6, type 7 and type 8 (HHV-6, HHV-7 and HHV-8) in the oral cavity of HIV-infected children/adolescents and verify the association between viral subtypes and clinical factors.

METHODS

The cells of oral mucosa were collected from 50 HIV infected children/adolescents, 3-13 years old (mean age 8.66). The majority (66%) of selected were girls, and they were all outpatients at the pediatric AIDS clinic of a public hospital in Rio de Janeiro. Nested-PCR was used to identify the viral types.

RESULTS

Absence of immunosuppression was observed in 66% of the children. Highly active antiretroviral therapy (HAART) was used by 72.1% of selected and moderate viral load was observed in 56% of the children/adolescents. Viral types were found in 86% of the children and the subtypes were: HSV-1 (4%), HSV-2 (2%), VZV (4%), EBV (0%), HCMV (24%), HHV6 (18%), HHV-7 (68%), HHV8 (0%).

CONCLUSIONS

The use of HAART has helped to reduce oral lesions, especially with herpes virus infections. The health professionals who work with these patients should be aware of such lesions because of their predictive value and the herpes virus can be found circulating in the oral cavity without causing lesions.

Periodontal disease in HIV-infected adults in the HAART era: Clinical, immunological, and microbiological aspects

The introduction of highly active antiretroviral therapy (HAART) has decreased the incidence and prevalence of several oral manifestations such as oral candidiasis, hairy leukoplakia, and Kaposi's sarcoma in HIV-infected patients. Regarding periodontal disease the findings are not clear. This disease represents a group of chronic oral diseases characterized by infection and inflammation of the periodontal tissues. These tissues surround the teeth and provide periodontal protection (the gingival tissue) and periodontal support (periodontal ligament, root cementum, alveolar bone). Clinical, immunological, and microbiological aspects of these diseases, such as linear gingival erythema (LGE), necrotizing periodontal diseases (NPD) (necrotizing ulcerative gingivitis [NUG], necrotizing ulcerative periodontitis [NUP] and necrotizing stomatitis), and chronic periodontitis, have been widely studied in HIV-infected individuals, but without providing conclusive results. The purpose of this review was to contribute to a better overall understanding of the probable impact of HIV-infection on the characteristics of periodontal infections.

Periodontal disease in HIV/AIDS

Since the early 1990's, the death rate from AIDS among adults has declined in most developed countries, largely because of newer antiretroviral therapies and improved access to these therapies. In addition, from 2006 to 2011, the total number of new cases of HIV infection worldwide has declined somewhat and has remained relatively constant. Nevertheless, because of the large numbers of existing and new cases of HIV infection, the dental practitioner and other healthcare practitioners will still be required to treat oral and periodontal conditions unique to HIV/AIDS as well as conventional periodontal diseases in HIV-infected adults and children. The oral and periodontal conditions most closely associated with HIV infection include oral candidiasis, oral hairy leukoplakia, Kaposi's sarcoma, salivary gland diseases, oral warts, other oral viral infections, linear gingival erythema and necrotizing gingival and periodontal diseases. While the incidence and prevalence of these oral lesions and conditions appear to be declining, in part because of antiretroviral therapy, dental and healthcare practitioners will need to continue to diagnose and treat the more conventional periodontal diseases in these HIV-infected populations. Finding low-cost and easily accessible and acceptable diagnostic and treatment approaches for both the microbiological and the inflammatory aspects of periodontal diseases in these populations are of particular importance, as the systemic spread of the local microbiota and inflammatory products of periodontal diseases may have adverse effects on both the progression of HIV infection and the effectiveness of antiretroviral therapy approaches. Developing and assessing low-cost and accessible diagnostic and treatment approaches to periodontal diseases, particularly in developing countries, will require an internationally coordinated effort to design and conduct standardized clinical trials.

A Comparison of Chronic Periodontitis in HIV-Seropositive Subjects and the General Population in the Ga-Rankuwa Area, South Africa

The effect of HIV infection on the prevalence and the rate of progression of chronic periodontitis is not clear. The aim of this study was to compare parameters associated with the severity of chronic periodontitis in terms of periodontal probing depths, gingival recession, plaque indexes, and bleeding indexes of HIV-seropositive subjects and healthy age-matched control subjects, and of HIV-seropositive subjects on highly active antiretroviral therapy and those not receiving such treatment. Two cohorts of subjects with chronic periodontitis were recruited for this study over a period of six months. There were 30 HIV-seropositive subjects, and 30 control subjects. Periodontal probing depths, gingival marginal recession, plaque indexes, and bleeding indexes were compared by HIV serostatus, the use of highly active antiretroviral therapy, and CD4+ T-cell counts. All participants were black persons between the age of 18 and 45 and were of a similar socioeconomic status and age. The results of this study indicate that chronic periodontitis in HIV-seropositive subjects is similar in terms of mean periodontal probing depth, gingival marginal recession, plaque index, and bleeding index to that in healthy age-matched control subjects, and a low CD4+ T-cell count does not appear to be a risk factor for increased severity of chronic periodontitis.

Relationship between herpesviruses and periodontopathogens in patients with HIV and periodontitis

BACKGROUND

The purpose of the present study is to verify a possible association between herpesviruses and periodontal pathogens in individuals with human immunodeficiency virus (HIV) and periodontitis.

METHODS

Twenty-seven patients with HIV and chronic periodontitis and 23 patients with HIV and gingivitis were included in the study. Probing depth, clinical attachment loss, gingival index, and plaque index were recorded. Blood, saliva, and subgingival plaque were processed for viral and bacterial identification. Bacteria were identified by 16S rRNA-based polymerase chain reaction and viruses by the nested polymerase chain reaction.

RESULTS

For the chronic periodontitis group, Epstein-Barr (EBV)-1 (70.4%) and Tannerella forsythia (Tf) (51.8%) presented higher detection in subgingival plaque and saliva (81.5% and 40.7%, respectively) than in blood (22% and 0%, respectively) (P <0.005 and P <0.0001, respectively). Porphyromonas gingivalis (Pg) was more frequent in subgingival plaque (77.7%; P <0.0001). In the gingivitis group, Pg and human cytomegalovirus (HCMV) presented higher frequency in subgingival plaque (95.6% and 91.3%, respectively; P <0.0001 and P = 0.004). Tf and EBV-1 were detected more frequently in subgingival plaque (47.8% and 78.3%, respectively) and saliva (52.2% and 52.2%, respectively; P = 0.004 and P <0.005) than in blood. EBV-1, EBV-1-HCMV, and presence of different viruses presented an association with periodontitis in saliva.

CONCLUSIONS

No association was detected for herpesviruses and periodontal pathogens in patients who are HIV-positive with periodontitis. EBV-1 and coinfection (EBV-1-HCMV) were associated with patients who are HIV-positive with periodontitis.

Identification of herpesviruses types 1 to 8 and human papillomavirus in acute apical abscesses

INTRODUCTION

It has been suggested that viruses, especially herpesviruses, can play a role in the pathogenesis of marginal and apical periodontitis. This study aimed to detect herpesviruses types 1 to 8, namely herpes simplex virus (HSV-1/2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), human herpesvirus-7 (HHV-7), and human herpesvirus-8 (HHV-8) as well as human papillomavirus (HPV) in acute apical abscesses.

METHODS

Twenty-four samples were taken by aspiration of the purulent exudate from acute apical abscesses. DNA extracted from clinical samples served as a template in single or nested polymerase chain reaction (PCR) assays for the detection of the target viruses.

RESULTS

Control PCR reactions with β-globin gene primers revealed that all samples but one had detectable human DNA. Of the 23 abscess samples positive for the β-globin gene, 14 (61%) were positive for at least one of the target human viruses. Thirteen (56.5%) cases had herpesvirus: HHV-8 occurred in 11 (48%), VZV and HHV-6B in two (9%), and HHV-7 and HSV-1/2 in one (4%). EBV and HCMV were not present in any of the examined samples. HPV was detected in three (13%) abscess samples. Viral coinfection was found in five cases, with one case harboring three of the targeted viruses.

CONCLUSION

A large number of abscess samples were positive for at least one target virus. Unexpectedly, HHV-8 was for the first time detected and in a high prevalence. Papillomavirus and other herpesviruses were also found for the first time in endodontic abscesses. Although these findings suggest an association, the specific role of viruses in the pathogenesis of acute apical abscesses awaits further clarification.

Oral infectious diseases: a potential risk factor for HIV virus recrudescence?

As the highly active antiretroviral therapy (HAART) has transitioned human immunodeficiency virus (HIV) infection into a 'chronic disease' management strategy, there is growing evidence that infection with non-HIV pathogens in HIV+ patients may have important public health implications in undermining HAART success and acquired immunodeficiency syndrome progression. Several bacterial and host cell products during infections with non-HIV pathogens have shown the capacity to regulate HIV replication in latently infected cells. A high prevalence of oral infections caused by bacteria, viruses and fungi has been described in HIV+ patients, including periodontal disease. The oral cavity appears to be a site of HIV pathogenesis and potential reservoir for the disease as HIV RNA and DNA forms are present in saliva as well as in gingival crevicular fluid, and oral epithelial cells are susceptible to either cell free or cell-associated HIV infection. The clinical and biological bases of potential associations between chronic oral inflammatory disorders, such as periodontal disease, and exacerbation of HIV viraemia have received little attention. This review attempts to evaluate the current understanding of HIV reactivation as a result of co-infection and/or inflammation induced by non-HIV pathogens in HIV-infected patients, and presents a hypothetic model about the potential role of periodontitis as a global oral infection that potentially contributes to HIV recrudescence.

EBV and CMV in chronic periodontitis: a prevalence study

Periodontitis is an infectious disease involving specific bacteria and viruses. Herpesviruses believed to play roles in it. The present study examines the presence of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in subgingival and supragingival plaque of 61 patients with chronic periodontitis and 40 healthy controls. A nested polymerase chain reaction method was used. The clinical parameters, clinical attachment level (CAL), probing depth (PD) and bleeding on probing (BOP) were examined. Prevalence of EBV- 1, EBV-2 and CMV were 73.8%, 4.9% and 59%; respectively. There was no association between the presence of EBV-1, EBV-2 and CMV with bleeding on depth.

Salivary microbiota of HIV-positive children and its correlation with HIV status, oral diseases, and total secretory IgA

AIM

This study aimed to investigate the prevalence and levels of salivary microorganisms in HIV-positive children, and their correlation to HIV status, oral lesions, and salivary IgA levels.

DESIGN

Forty-two HIV-positive and 36 control children were clinically examined, had their saliva collected and processed for the microbiological analysis of 38 bacterial taxa by the checkerboard method, and salivary IgA quantification by ELISA.

RESULTS

The majority of the species tested were more prevalent in control children than in the HIV group. Mean concentration of total salivary IgA was similar in both groups. High levels of Veillonella parvula were found in children with cheilitis and herpes. Tannerella forsythia, Eikenella Corrodens, and Propionibacterium acnes were prevalent in children with gingivitis, while Fusobacterium periodonticum, Streptococcus gordonii, and Streptococcus oralis were significantly more frequent in children with no oral lesions. Significant negative correlations between salivary IgA levels and Eubacterium nodatum and oral streptococci were observed (P < 0.05).

CONCLUSION

HIV-seropositive children presented significantly lower prevalence and levels of several bacterial species in saliva; HIV-positive children are able to mount a mucosal immune response; HIV-seropositive children under highly active antiretroviral therapy presented low prevalence of oral lesions.

Herpesviral-bacterial synergy in the pathogenesis of human periodontitis

PURPOSE OF REVIEW

Periodontitis is an infectious disease, but the specific mechanisms by which tooth-supportive tissues are lost remain obscure. This article proposes an infectious disease model for periodontitis in which herpesviral-bacterial interactions assume a major etiopathogenic role.

RECENT FINDINGS

Epstein-Barr virus type 1, cytomegalovirus and other herpesviruses occur at a high frequency in aggressive periodontitis lesions. Also, herpesvirus-infected periodontitis lesions tend to harbor elevated levels of classic periodontopathic bacteria, including Porphyromonas gingivalis, Dialister pneumosintes, Prevotella intermedia, Prevotella nigrescens, Campylobacter rectus, Treponema denticola and Actinobacillus (Aggregatibacter) actinomycetemcomitans.

SUMMARY

Conceivably, a herpesvirus active infection in the periodontium impairs local defenses, thereby permitting overgrowth and increased aggressiveness of periodontopathic bacteria. In turn, periodontal pathogenic bacteria may augment the virulence of periodontal herpesviruses. It is suggested that interactions among herpesviruses and specific bacterial species constitute an important pathogenetic feature of periodontitis and maybe also of various non-oral infections.

Signaling cascades triggered by bacterial metabolic end products during reactivation of Kaposi's sarcoma-associated herpesvirus

The present studies explore the role of polymicrobial infection in the reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV) and analyze signaling pathways activated upon this induction. We hypothesized that activation of the cellular stress-activated mitogen-activated protein kinase (MAPK) p38 pathway would play a key role in the bacterium-mediated disruption of viral latency similar to that of previously reported results obtained with other inducers of gammaherpesvirus lytic replication. KSHV within infected BCBL-1 cells was induced to replicate following exposure to metabolic end products from gram-negative or -positive bacteria that were then simultaneously exposed to specific inhibitors of signal transduction pathways. We have determined that bacterium-mediated induction of lytic KSHV infection is significantly reduced by the inhibition of the p38 MAPK pathway. In contrast, inhibition of the phosphatidylinositol 3-kinase pathway did not impair induction of lytic replication or p38 phosphorylation. Protein kinase C, though activated, was not the major pathway used for bacterium-induced viral reactivation. Furthermore, hyperacetylation of histones 3 and 4 was detected. Collectively, our results show that metabolic end products from these pathogens induce lytic replication of KSHV in BCBL-1 cells primarily via the activation of a stress-activated MAPK pathway. Importantly, we demonstrate for the first time a mechanism by which polymicrobial bacterial infections result in KSHV reactivation and pathogenesis.

Prevalence of some herpesviruses in gingival crevicular fluid

BACKGROUND

The herpesviruses, ancient pathogens which have co-evoluted with human, are etiologically associated with a number of diseases, from asymptomatic to oncogenic and mortal diseases. It seems that some of them have also an important role in the pathogenesis of human periodontal disease.

OBJECTIVE

This study aimed to determine the prevalence of Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), human herpesvirus 8 (HHV-8) and human cytomegalovirus (HCMV) in gingival crevicular fluid (GCF) and, eventually, to find the correlation between specific virus types and clinical parameters which are important in periodontitis, like plaque index (PI), gingival index (GI) and probing depth (PD).

STUDY DESIGN

A polymerase chain reaction (PCR) and digestion of PCR products with restriction endonuclease were employed to identify the presence of EBV, HHV-6, HHV-8 and HCMV.

RESULTS

Out of 66 samples of GCF taken from the patients with periodontal disease, EBV was found in 29 (43.9%), HHV-6 in 16 (24.2%) and HCMV in 2 (3%) samples, while in the samples of healthy persons, these viruses were not found. HHV-8 was detected neither in the patients with periodontitis nor in healthy control group. More positive results were found in clinical samples taken from people with higher PI and GI and in the samples taken from the patients with medium PD (PD=3-6mm). In all HHV-6 positive samples, we found only variant A; as for EBV positive samples, type A and type B were identified and also co-infection with the two types. It seems that there is a correlation between PI, PD and EBV types, but no correlation was found between EBV types and GI or HHV-6 types and PI, PD, GI.

CONCLUSIONS

The present findings confirm some association between herpesviruses and human periodontitis.

Current trends of HIV disease of the mouth

HIV infection affects residents of all countries of the world, but the greater majority of affected individuals reside in the developing world. In the past decade there have been substantial changes in the management of HIV disease, particularly the introduction of highly active antiretroviral therapy (HAART). Such agents have reduced significantly the morbidity and mortality associated with HIV disease, however, they are not available for most HIV-infected individuals in the developing world. There is now considerable understanding of the molecular epidemiology, transmission and therapy of the common opportunistic oral infections of HIV disease, and as a consequence of improved anti-HIV strategies, the frequency and severity of oral disease associated with HIV infection have reduced considerably, although HAART may predispose to human papilloma virus infection of the mouth and potentially increase the risk of later oral squamous cell carcinoma. Despite advances in clinical care the majority of individuals with HIV disease worldwide will continue to develop oral disease, as they are resident in the developing world and do not have ready access to even simple therapies.

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.

Interactions between human immunodeficiency virus and herpes viruses within the oral mucosa

There is evidence from clinical case reports and epidemiological studies that human immunodeficiency virus (HIV) can be transmitted through oral sex. Herpes viruses that appear in the oral mucosa might influence the oral replication of HIV. A review of data suggesting that interactions occur between HIV and herpes viruses indicates that such interactions might operate in the oral mucosa. Defining the mechanisms by which herpes viruses interact with HIV in the oral mucosa should permit intervention measures to be targeted more precisely.

Prevalence of Human Herpesviruses in Patients with Aggressive Periodontitis

BACKGROUND

Recent studies have demonstrated that various human viruses, especially cytomegalovirus (HCMV) and Epstein-Barr virus type-1 (EBV-1), seem to play a part in the pathogenesis of human periodontitis. The aim of this investigation was to evaluate the subgingival presence of HCMV and EBV in patients with aggressive periodontitis (AgP) and healthy subjects and to examine the effect of treatment on the incidence of these viruses 3 months following surgery.

METHODS

A polymerase chain reaction (PCR) method determined the presence of HCMV and EBV-1. Subgingival plaque samples from 17 consecutive AgP patients and 16 healthy controls were collected. The following indices were measured: plaque index (PI), gingival index (GI), probing depths (PD), and clinical attachment loss (CAL). Clinical parameters were assessed pretherapy and at 3 months following surgical and antimicrobial therapy.

RESULTS

HCMV was detected in 64.7% of AgP patients but not detected in healthy subjects (P < 0.001) and EBV-1 in 70.6% of AgP patients and 6.3% of the healthy controls (P < 0.001). HCMV and EBV-1 coinfection was detected in 41.7% of AgP patients. A statistically significant decrease was found in all clinical parameters 3 months after treatment. There was a statistically significant decrease in HCMV and EBV-1 following therapy (P < 0.001; no HCMV; 1 patient with EBV-1).

CONCLUSIONS

These findings indicate that subgingival presence of EBV-1 HCMV is strongly associated with aggressive periodontitis, and coinfection with HCMV and EBV-1 appears to be particularly deleterious to periodontal health.

A TEM/SEM study of the microbial plaque overlying the necrotic gingival papillae of HIV-seropositive, necrotizing ulcerative periodontitis

The purpose of this study was to examine by transmission (TEM) and scanning electron microscopy (SEM) the supragingival microbial plaque overlying the ulcerated gingival papillae of necrotizing ulcerative periodontitis (NUP) lesions in HIV-seropositive patients. The microbiota of NUP and HIV-seropositive patients with periodontitis has been reported to be similar to that of conventional periodontitis in non-infected subjects, although several investigators have also reported high recovery rates of microbes not generally associated with the indigenous oral microbial flora. Light and electron microscopic observations and microbial culture studies indicate a similar high prevalence of spirochetes in both necrotizing ulcerative gingivitis (NUG) and NUP. In addition, several studies have reported more frequent isolation of Candida albicans from diseased periodontal sites in HIV-seropositive patients than from non-diseased sites. Ten male and six female patients, each HIV-seropositive and exhibiting NUP, constituted the study population. Two biopsies of involved gingival papillae from between posterior teeth were obtained from each patient and processed for examination by both TEM and SEM. Microscopic examination revealed a surface biofilm comprised of a mixed microbial flora of various morphotypes in 81.3% of biopsy specimens. The subsurface flora featured dense aggregations of spirochetes in 87.5% of specimens. Zones of aggregated polymorphonuclear leukocytes and necrotic cells were also noted. Yeasts were observed in 65.6% of specimens and herpes-like viruses in 56.5% of the specimens. Collectively, except for the presence of yeast and viruses, the results suggest that the microbial flora and possibly the soft tissue lesions of NUP and necrotizing ulcerative gingivitis are very similar.

HHV-6, HHV-7, HHV-8 in gingival biopsies from chronic adult periodontitis patients. A case-control study

BACKGROUND

Recent reports have suggested that various herpesviruses may be involved in the occurrence and progression of different forms of periodontal disease.

OBJECTIVE

The objective of the present study was to investigate the presence of the novel herpesviruses HHV-6, HHV-7 and HHV-8 in gingival biopsies from patients affected by chronic adult periodontitis. As control, gingival biopsies from periodontally healthy subjects were analysed.

MATERIALS AND METHODS

Gingival biopsies were harvested from 23 volunteers: 13 patients affected by chronic adult periodontitis (CAP) and 10 periodontally healthy subjects. Each CAP patient contributed two biopsies involving the epithelium and connective tissue facing the sulcus/periodontal pockets: one biopsy from a site having a probing pocket depth (PPD) > or =5 mm and presenting with bleeding upon probing (affected site) at the time of biopsy collection, and the other biopsy from a site with PPD< or =3 mm and without bleeding on probing (nonaffected site). After DNA extraction, nested PCR was used in herpesvirus identification.

RESULTS

HHV-6 DNA sequences were detected in one non-affected site (8%) and no affected sites (0%) of CAP patients. One biopsy (10%) in healthy subjects revealed HHV-6 positivity. Tissue specimens in 10/13 CAP patients (77%) and 7/10 healthy subjects (70%) contained HHV-7 DNA. HHV-7 prevalence in affected and nonaffected sites of CAP patients was 77% and 54%, respectively. HHV-8 was detected in 7.7% of CAP patients and 0% of healthy subjects.

CONCLUSIONS

Gingival tissue may act as a reservoir for HHV-7. A high prevalence of HHV-7 was detected in both periodontally diseased and healthy individuals. The prevalence of HHV-6 and -8 was similarly low in both groups. Our data do not support an association of investigated herpesvirus species with destructive periodontal disease.

Detection of human viruses in patients with chronic periodontitis and the relationship between viruses and clinical parameters

BACKGROUND

Recent studies have demonstrated that various human viruses, especially cytomegalovirus (HCMV), Epstein-Barr virus type-1 (EBV-1), and herpes simplex virus (HSV), seem to play a part in the pathogenesis of human periodontitis. Little information is available on the relationship between these viruses and clinical periodontal parameters in patients with chronic periodontitis. This study examined the occurrence of HCMV, EBV-1, and HSV in patients with chronic periodontitis and the relationship between these viruses and clinical parameters.

METHODS

A nested polymerase chain reaction (PCR) method determined the presence of HCMV, EBV-1, and HSV. Subgingival plaque samples from 30 patients with chronic periodontitis and 21 randomly selected healthy controls were collected by paper points, and clinical measurements were recorded from both sampling sites and entire dentition. The following indices were measured: plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment loss (CAL).

RESULTS

HCMV was detected in 44.3% of chronic periodontitis patients and 14.3% of healthy persons (P < 0.05); EBV-1 in 16.7% of chronic periodontitis patients and 14.3% of healthy persons (P = 1.00); and HSV in 6.7% of chronic periodontitis patients and in no healthy persons. HCMV and EBV-1 detected and undetected sites in patients with periodontitis showed statistically significant differences in sampling clinical depth (SPD) and sampling clinical attachment loss (SCAL). Differences in the measurements of PI of entire dentition and GI of entire dentition between HSV detected and undetected sites were statistically significant.

CONCLUSIONS

Findings of the present study confirm the frequent presence of HCMV in crevicular samples of chronic periodontitis lesions, and suggest a strong relationship between the presence of HCMV and EBV-1 in subgingival areas and the measurements of probing depth and probing attachment loss.

An update on HIV and periodontal disease

With the advent of newer pharmacological approaches to the treatment of human immunodeficiency virus (HIV) infection, the incidence and progression of both atypical and conventional periodontal diseases are changing. The incidence of necrotizing periodontitis and gingival diseases of fungal origin appears to be on the decline as a result of these therapies that have led to increased life spans for HIV patients. However, in cases where these therapies lose their effectiveness and HIV patients relapse into an immunosuppressed state, these conditions may recur. Recent evidence has shown that HIV patients with more conventional periodontal diseases such as chronic periodontitis may have increased attachment loss and gingival recession when compared to their HIV-negative counterparts. This pattern of loss of periodontal support may be due in part to a diffuse invasion of opportunistic bacterial infections, viruses, and fungi into the gingival tissue, leading to a more elevated and more diffuse destructive inflammatory response in the periodontal soft and hard tissues. While the accepted approaches to treating the spectrum of periodontal diseases in HIV patients remain essentially unchanged over the past 15 years, the impact of newer systemic therapies on patient immunocompetence may influence treatment decisions.

Periodontal diseases and HIV infection

The workshop considered six related questions about periodontal changes seen in HIV infection. 1) To what extent are specific periodontal changes associated with HIV? 2) Are conventional periodontal diseases modified by HIV infection? The changes associated with HIV appear to be modified presentations of conventional diseases. Research should identify initiation and progression factors for necrotizing diseases. 3) What is the role of geography and transmission groups? These questions cannot be answered without greater standardisation of research methods. 4) Has the epidemiology of these changes changed with the advent of new therapies? The data required to answer this question should be available soon but this question is irrelevant to the vast majority of people with HIV. 5) What pathogens are involved in periodontal changes seen in HIV infection? The role of Candida spp. and other potential pathogens requires further investigation. 6) What management protocols are suitable for the periodontal diseases? The significance of periodontal diseases among people with HIV in developing countries is not known. Further research is needed of the effectiveness of interventions especially necrotizing disease in developing countries. The quality of research of these diseases would be enhanced by standardized approaches. A list of relevant variables might prevent their omission from studies.

Synergism between HIV and other viruses in the mouth

The HIV family replicate in and are shed from the mouth. Oral sexual practices potentially contribute to the overall extent of HIV transmission, particularly if high-risk practices are not restricted. Herpesviruses and papillomaviruses that appear in the oral cavity can determine oral HIV replication. The mechanisms probably include heterologous transactivation, enhanced expression of HIV receptors and co-receptors in target cells, release of cytokines and chemokines, and production of superantigens. Oral diseases peculiar to, or more common in, the HIV-infected patient further predispose to heightened oral HIV replication and trafficking. Defining the mechanisms by which oral viruses interact with HIV in the co-infected host should permit intervention measures against oral HIV transmission to be more precisely targeted.