Oncogenic Oral Human Papillomavirus Clearance Patterns over 10 Years

BACKGROUND

Effective screening for oropharyngeal cancer is lacking. Four oncogenic HPV clearance definitions were explored to understand long-term natural history for persistent oncogenic oral HPV (oncHPV), the precursor of oropharyngeal cancer.

METHODS

Prospective multicenter cohort of participants living with/at-risk for HIV, with oral rinse and gargle samples collected every 6 to 12 months for up to 10 years and tested for oncHPV. HPV clearance definitions included 1 (clear1), 2 (clear2), 3 (clear3) consecutive negatives, or being negative at last two visits (clearlast).

RESULTS

Median time to clearance of oncHPV exceeded 2 years for conservative definitions (clear3: 2.38, clearlast: 2.43), but not lenient (clear1: 0.68, clear2: 1.15). By clear3, most incident infections cleared at 2, 5, 8 years (55.1%, 75.6%, 79.1%), contrary to prevalent infections (37.1%, 52.5%, 59.5%, respectively). In adjusted analysis, prevalent oncHPV, older age, male sex, and living with HIV were associated with reduced clearance. Of 1,833 subjects screened, 13.8% had prevalent oncHPV and 47.5% of those infections persisted ≥5 years, representing 6.5% of persons screened. Two men with prevalent oral HPV16 developed incident oropharyngeal cancer [IR = 1.62 per 100 person-years; 95% confidence interval (CI), 0.41-6.4]. Many with oral HPV16 persisted ≥5 years (and/or developed HPV-oropharyngeal cancer) among those with 2 (72.2%), ≥2 of first 3 (65.7%), or 3 (80.0%) consecutive positive oHPV16 tests, but not after 1 (39.4%).

CONCLUSIONS

In our 10-year study, most incident infections cleared quickly. However, half of prevalent oncHPV persisted ≥5 years, suggesting increased risk with persistent oncHPV at >2 visits.

IMPACT

We identified groups with persistent oncHPV at increased risk of oropharyngeal cancer and contextualized risk levels for those with oral HPV16 infection.

Oral SARS-CoV-2 host responses predict the early COVID-19 disease course

Objectives

Oral fluids provide ready detection of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and host responses. This study sought to determine relationships between oral virus, oral anti-SARS-CoV-2-specific antibodies, and symptoms.

Methods

Saliva/throat wash (saliva/TW) were collected from asymptomatic and symptomatic, nasopharyngeal (NP) SARS-CoV-2 RT-qPCR+, subjects (n=47). SARS-CoV-2 RT-qPCR, N-antigen detection by immunoblot and lateral flow assay (LFA) were performed. RT-qPCR targeting viral subgenomic RNA (sgRNA) was sequence confirmed. SARS-CoV-2-anti-S protein RBD LFA assessed IgM and IgG responses. Structural analysis identified host salivary molecules analogous to SARS-CoV-2-N-antigen. Statistical analyses were performed.

Results

At baseline, LFA-detected N-antigen was immunoblot-confirmed in 82% of TW. However, only 3/17 were saliva/TW qPCR+. Sixty percent of saliva and 83% of TW demonstrated persistent N-antigen at 4 weeks. N-antigen LFA signal in three negative subjects suggested potential cross-detection of 4 structurally analogous salivary RNA binding proteins (alignment 19-29aa, RMSD 1-1.5 Angstroms). At entry, symptomatic subjects demonstrated replication-associated sgRNA junctions, were IgG+ (94%/100% in saliva/TW), and IgM+ (75%/63%). At 4 weeks, SARS-CoV-2 IgG (100%/83%) and IgM (80%/67%) persisted. Oral IgG correlated 100% with NP+PCR status. Cough and fatigue severity (p=0.0008 and 0.016), and presence of nausea, weakness, and composite upper respiratory symptoms (p=0.005, 0.037 and 0.017) were negatively associated with oral IgM. Female oral IgM levels were higher than male (p=0.056).

Conclusion

Important to transmission and disease course, oral viral replication and persistence showed clear relationships with select symptoms, early Ig responses, and gender during early infection. N-antigen cross-reactivity may reflect mimicry of structurally analogous host proteins.

Oral SARS-CoV-2 host responses predict the early COVID-19 disease course

Objectives

Oral fluids provide ready detection of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and host responses. This study sought to determine relationships between oral virus, oral anti-SARS-CoV-2-specific antibodies, and symptoms.

Methods

Saliva/throat wash (saliva/TW) were collected from asymptomatic and symptomatic, nasopharyngeal (NP) SARS-CoV-2 RT-qPCR+, subjects (n=47). SARS-CoV-2 RT-qPCR, N-antigen detection by immunoblot and lateral flow assay (LFA) were performed. RT-qPCR targeting viral subgenomic RNA (sgRNA) was sequence confirmed. SARS-CoV-2-anti-S protein RBD LFA assessed IgM and IgG responses. Structural analysis identified host salivary molecules analogous to SARS-CoV-2-N-antigen. Statistical analyses were performed.

Results

At baseline, LFA-detected N-antigen was immunoblot-confirmed in 82% of TW. However, only 3/17 were saliva/TW qPCR+. Sixty percent of saliva and 83% of TW demonstrated persistent N-antigen at 4 weeks. N-antigen LFA signal in three negative subjects suggested potential cross-detection of 4 structurally analogous salivary RNA binding proteins (alignment 19-29aa, RMSD 1-1.5 Angstroms). At entry, symptomatic subjects demonstrated replication-associated sgRNA junctions, were IgG+ (94%/100% in saliva/TW), and IgM+ (75%/63%). At 4 weeks, SARS-CoV-2 IgG (100%/83%) and IgM (80%/67%) persisted. Oral IgG correlated 100% with NP+PCR status. Cough and fatigue severity (p=0.0008 and 0.016), and presence of nausea, weakness, and composite upper respiratory symptoms (p=0.005, 0.037 and 0.017) were negatively associated with oral IgM. Female oral IgM levels were higher than male (p=0.056).

Conclusion

Important to transmission and disease course, oral viral replication and persistence showed clear relationships with select symptoms, early Ig responses, and gender during early infection. N-antigen cross-reactivity may reflect mimicry of structurally analogous host proteins.

HIVtat Alters Epithelial Differentiation State and Increases HPV16 Infectivity in Oral Keratinocytes

Human Papillomavirus (HPV)-associated oral disease has increased during the era of HIV antiretroviral therapy. HPV and HIV proteins may be co-present at mucosal surfaces. Recent published studies have determined that HIVtat is secreted in the saliva and has been detected in oral mucosa even in the context of antiretroviral therapy. We hypothesized that HIVtat promoted oral HPV pathogenesis. Clinical HPV16 cloned episomes were introduced into differentiated oral epithelial cells (OKF6tert1). HIVtat mediated transactivation, DNA damage, oxidative stress, and effects on cellular differentiation were assessed. Detection of keratin 10 and of loricrin confirmed terminal differentiation. Sodium butyrate-treated (NaB) cells demonstrated an eight-fold increase in cross-linked involucrin, suggesting full terminal differentiation. HIVtat modulated this differentiation both in the presence and absence of NaB. Later viral events, including E6* and E1^E4 gene expression were assessed. HIVtat mediated relief of repressed L1 expression that mapped to a known inhibitory region (nucleotides 5561-6820). Viruses from HIVtat co-expressing cells exhibited robust de novo HPV16 infection. In conclusion, a novel oral keratinocyte monolayer system supported replication of an HPV16 clinical isolate where direct HIVtat and oral HPV interactions enhanced HPV de novo infection.

Differentiated Oral Epithelial Cells Support the HPV Life Cycle

Human Papillomavirus (HPV) associated oral disease continues to increase, both in the context of immune competence and of immune suppression. There are few models of oral HPV infection and current models are laborious. We hypothesized that differentiated oral epithelial cells could support the HPV life cycle. Clinical HPV16 cloned episomes were introduced into differentiated oral epithelial cells (OKF6tert1). Viral and cellular gene expression was assessed in the presence or absence of sodium butyrate, a differentiating agent that moved the cells to full terminal differentiation. Detection of keratin 10, cross-linked involucrin, and loricrin in the presence and absence of sodium butyrate confirmed terminal differentiation. Increasing sodium butyrate concentrations in the absence of HPV, were associated with decreased suprabasal markers and increased terminal differentiation markers. However, in the presence of HPV and of increasing sodium butyrate concentrations, both mitotic and suprabasal markers were increased and the terminal differentiation marker, loricrin, decreased. In this unique differentiated state, early and late viral gene products were detected including spliced mRNAs for E6*, E1^E4, and L1. E7 and L1 proteins were detected. The ratio of late (E1^E4) to early (E6/E7) transcripts in HPV16+ OKF6tert1 cells was distinct compared to HPV16+ C33a cells. Consistent with permissive HPV replication, DNA damage responses (phospho-chk2, gamma-H2AX), HPV E2-dependent LCR transactivation, and DNase-resistant particles were detected and visualized by transmission electron microscopy. In sum, monolayers of differentiated immortalized oral epithelial cells supported the full HPV life cycle. HPV may optimize the differentiation state of oral epithelial cells to facilitate its replication.

Interferon activated gene 204 protects against bone loss in experimental periodontitis

BACKGROUND

Periodontal destruction can be the result of different known and yet-to-be-discovered biological pathways. Recent human genetic association studies have implicated interferon-gamma inducible protein 16 (IFI16) and absent in melanoma 2 (AIM2) with high periodontal interleukin (IL)-1β levels and more destructive disease, but mechanistic evidence is lacking. Here, we sought to experimentally validate these observational associations and better understand IFI16 and AIM2's roles in periodontitis.

METHODS

Periodontitis was induced in Ifi204-/- (IFI16 murine homolog) and Aim2-/- mice using the ligature model. Chimeric mice were created to identify the main source cells of Ifi204 in the periodontium. IFI16-silenced human endothelial cells were treated with periodontal pathogens in vitro. Periodontal tissues from Ifi204-/- mice were evaluated for alveolar bone (micro-CT), cell inflammatory infiltration (MPO+ staining), Il1b (qRT-PCR), and osteoclast numbers (cathepsin K+ staining).

RESULTS

Ifi204-deficient mice> exhibited >20% higher alveolar bone loss than wild-type (WT) (P < 0.05), while no significant difference was found in Aim2-/- mice. Ifi204's effect on bone loss was primarily mediated by a nonbone marrow source and was independent of Aim2. Ifi204-deficient mice had greater neutrophil/macrophage trafficking into gingival tissues regardless of periodontitis development compared to WT. In human endothelial cells, IFI16 decreased the chemokine response to periodontal pathogens. In murine periodontitis, Ifi204 depletion elevated gingival Il1b and increased osteoclast numbers at diseased sites (P < 0.05).

CONCLUSIONS

These findings support IFI16's role as a novel regulator of inflammatory cell trafficking to the periodontium that protects against bone loss and offers potential targets for the development of new periodontal disease biomarkers and therapeutics.

Periodontal Treatment Reduces Circulating Pro-Inflammatory Cytokine and Chemokine Levels in African American HIV+ Individuals with Virological Suppression

Introduction

Periodontal Disease (PD), a chronic inflammatory disease, is highly prevalent among Persons Living With HIV (PLWH) and is characterized by microbial symbiosis and oxidative stress. Our hypothesis stipulates that periodontal therapy attenuates systemic inflammatory and bacterial burden while improving periodontal status in PLWH.

Methods

Sixteen African Americans (AA) with suppressed HIV viremia on long-term Antiretroviral Therapy (ART) were recruited to this study. Participants were placed into two groups, based on their dental care status: group 1 (In-Care, IC) and group 2 (Out of Care, OC). Periodontal health was investigated at baseline, 3 months, 6 months, and 12 months. Cytokine/chemokines, microbial phyla, and Asymmetric Dimethylarginine (ADMA, a marker for endothelial cell dysfunction) levels were assessed in the serum. Statistical comparisons between groups and at different visits were performed using multiple comparison tests.

Results

Across longitudinal visits, periodontal treatment significantly reduced the levels of several cytokines and chemokines. At baseline, the out of care group had significantly higher blood levels of ADMA and actinobacteria than the IC group. Periodontal treatment significantly altered the abundance of circulating genomic bacterial DNA for various phyla in out of care group.

Conclusions

Periodontal treatment interventions effectively attenuated circulating pro-inflammatory cytokines and altered microbial translocation, both critical drivers of systemic inflammation in PLWH.

Distinct Microbial Signatures between Periodontal Profile Classes

Precise classification of periodontal disease has been the objective of concerted efforts and has led to the introduction of new consensus-based and data-driven classifications. The purpose of this study was to characterize the microbiological signatures of a latent class analysis (LCA)-derived periodontal stratification system, the Periodontal Profile Class (PPC) taxonomy. We used demographic, microbial (subgingival biofilm composition), and immunological data (serum IgG antibody levels, obtained with checkerboard immunoblotting technique) for 1,450 adult participants of the Dental Atherosclerosis Risk in Communities (ARIC) study, with already generated PPC classifications. Analyses relied on t tests and generalized linear models with Bonferroni correction. Men and African Americans had higher systemic antibody levels against most microorganisms compared to women and Caucasians (P < 0.05). Healthy individuals (PPC-I) had low levels of biofilm bacteria and serum IgG levels against most periodontal pathogens (P < 0.05). Subjects with mild to moderate disease (PPC-II to PPC-III) showed mild/moderate colonization of multiple biofilm pathogens. Individuals with severe disease (PPC-IV) had moderate/high levels of biofilm pathogens and antibody levels for orange/red complexes. High gingival index individuals (PPC-V) showed moderate/high levels of biofilm Campylobacter rectus and Aggregatibacter actinomycetemcomitans. Biofilm composition in individuals with reduced periodontium (PPC-VI) was similar to health but showed moderate to high antibody responses. Those with severe tooth loss (PPC-VII) had significantly high levels of multiple biofilm pathogens, while the systemic antibody response to these microorganisms was comparable to health. The results support a biologic basis for elevated risk for periodontal disease in men and African Americans. Periodontally healthy individuals showed a low biofilm pathogen and low systemic antibody burden. In the presence of PPC disease, a microbial-host imbalance characterized by higher microbial biofilm colonization and/or systemic IgG responses was identified. These results support the notion that subgroups identified by the PPC system present distinct microbial profiles and may be useful in designing future precise biological treatment interventions.

Implications in the quantification of SARS-CoV2 copies in concurrent nasopharyngeal swabs, whole mouth fluid and respiratory droplets

OBJECTIVE

Association of SARS-CoV2 burden in the aerodigestive tract with the disease is sparsely understood. We propose to elucidate the implications of SARS-CoV2 copies in concurrent nasopharyngeal swab (NPS), whole mouth fluid (WMF) and respiratory droplet (RD) samples on disease pathogenesis/transmission.

METHODS

SARS-CoV2 copies quantified by RT-PCR in concurrent NPS, WMF and RD samples from 80 suspected COVID-19 patients were analysed with demographics, immune response and disease severity.

RESULTS

Among the 55/80 (69 %) NPS-positive patients, SARS-CoV2 was detected in 44/55 (80 %) WMF (concordance with NPS-84 %; p = 0.02) and 17/55 (31 %) RD samples. SARS-CoV2 copies were similar in NPS (median:8.74 × 10^5) and WMF (median:3.07 × 10^4), but lower in RD (median:3.60 × 10^2). The 25-75 % interquartile range of SARS-CoV2 copies in the NPS was significantly higher in patients who shed the virus in WMF (p = 0.0001) and RD (p = 0.01). Multivariate analyses showed that hospitalized patients shed significantly higher virus copies in the WMF (p = 0.01). Hospitalized patients with more severe disease (p = 0.03) and higher IL-6 values (p = 0.001) shed more SARS-CoV2 virus in the RD.

CONCLUSIONS

WMF may be used reliably as a surrogate for diagnosis. High copy numbers in the NPS probably imply early disease onset, while in the WMF and RD may imply more severe disease and increased inflammation.

Viruses and oral diseases in HIV-infected individuals on long-term antiretroviral therapy: What are the risks and what are the mechanisms?

As a result of the extension of life span produced by increasing access to combined antiretroviral therapy, people living with HIV/AIDS (PLWH) face new challenges from comorbidities. Although advances in medical care for HIV infection have dramatically reduced opportunistic infections and AIDS-defining cancers, some non-AIDS-defining cancers (NADC) and specific oral diseases such as periodontitis and salivary gland disease are now more prevalent. Cancer prevention is, therefore, a priority issue in care of PLWH, stressing both restoration of immune function and reduction of non-HIV cancer risk factors (tobacco in all its forms; areca nut; heavy alcohol consumption; diets lacking antioxidant vitamins and minerals; and oncogenic virus infections) through specific interventions, especially tobacco and areca nut cessation and alcohol moderation. Detection of oral high-risk human papillomaviruses (HR-HPV) and the universal preventive HPV vaccination among PLWH should be promoted to reduce the malignancy burden, along with routine oral examinations which remain the cheapest, most reliable, most reproducible, and non-invasive tool to identify suspicious lesions. Also, considerations of oral inflammation and periodontal health are important to replication and gene expression of viruses in the mouth. Considering that a key risk factor for this scenario is the presence of oncogenic virus infection such as several members of the human herpesvirus and human papillomavirus families, here we analyze the variables involved in the seeming increase in comorbidities in PLWH.

Women's HIV disclosure to the dentist: Does frequent contact matter?

OBJECTIVES

Research has shown inconsistent patterns of patients' HIV serostatus disclosure to their dentists. Common barriers to disclosure have included confidentiality concerns, fear of treatment refusal, and discrimination. This study evaluated the prevalence of HIV serostatus disclosure to the dentist, whether the frequency of dental care utilization is associated with disclosure, and reasons for nondisclosure among women living with HIV.

METHODS

We administered a cross-sectional oral health survey to 1,526 women living with HIV in the Women's Interagency HIV Study including questions regarding HIV serostatus disclosure to dentists. Logistic regression models were used to analyze the association between dental care utilization (at least annually versus less than annually) and HIV serostatus disclosure to dentists.

RESULTS

Overall, 83 percent of women reported that they disclosed their HIV serostatus to their dentist. The most common reasons for nondisclosure were: a) the dentist did not ask, b) believing that the dentist did not need to know, and c) not having a consistent dentist. In the multivariable logistic regression model, at least annual dental care utilization, compared to less than annual, led to a 59 percent reduction in the odds of HIV nondisclosure to the dentist.

DISCUSSION

Study findings highlight that dentists who see their patients infrequently should consider methods for overcoming barriers to HIV nondisclosure and the possibility that their patient's HIV serostatus is undisclosed. Educating women living with HIV about how disclosure to dentists is a critical component of their dental assessment and treatment, and how preventive dental treatment can improve overall health outcomes, is important.

Oral health-related quality of life and unmet dental needs among women living with HIV

BACKGROUND

Oral health-related quality of life (OHRQoL) is a multidimensional, perception-based measure of how oral health affects social and physical functioning and self-image. OHRQoL is important for assessing women living with HIV (WLWH) who may have unmet dental needs and experience disparities that impact dental care accessibility.

METHODS

In 2016, the authors conducted an assessment of OHRQoL among a national sample of 1,526 WLWH in the Women's Interagency HIV Study using the Oral Health Impact Profile instrument, which assesses the frequency of 14 oral health impact items. OHRQoL was measured using multivariable linear regression with a negative binomial distribution to assess the association between report of a recent unmet dental need and OHRQoL.

RESULTS

"Fair or poor" oral health condition was reported by 37.8% (n = 576) of WLWH. Multivariable linear regression showed that unmet dental needs had the strongest positive association with poor OHRQoL (difference in Oral Health Impact Profile mean, 2.675; P < .001) compared with not having unmet needs. The frequency of dental care utilization was not associated with higher OHRQoL. Older age, fair or poor dental condition, smoking, symptoms of anxiety and loneliness, and poor OHRQoL were also associated with worse OHRQoL.

CONCLUSION

Self-perceived impact of oral health on social and physical function and self-image, as measured by OHRQoL, may be an easily assessable but underrecognized aspect of OHRQoL, particularly among women aging with HIV.

PRACTICAL IMPLICATIONS

Dentists should implement OHRQoL assessments in their management of the care of patients with HIV to identify those who do have significant oral health impacts.

Gender Inequalities in the Dental Workforce: Global Perspectives

The aim of this review is to investigate the growth of diversity and inclusion in global academic dental research with a focus on gender equality. A diverse range of research methodologies were used to conduct this review, including an extensive review of the literature, engagement of key informants in dental academic leadership positions around the world, and review of current data from a variety of national and international organizations. Results provide evidence of gender inequalities that currently persist in dental academics and research. Although the gender gap among graduating dental students in North America and the two most populous countries in Europe (the United Kingdom and France) has been narrowed, women make up 30% to 40% of registered dentists in countries throughout Europe, Oceania, Asia, and Africa. In academic dentistry around the globe, greater gender inequality was found to correlate with higher ranking academic and leadership positions in the United States, United Kingdom, several countries in European Union, Japan, and Saudi Arabia. Further disparities are noted in the dental research sector, where women make up 33% of dental researchers in the European Union, 35% in North America, 55% in Brazil, and 25% in Japan. Family and societal pressures, limited access to research funding, and lack of mentoring and leadership training opportunities are reported as also contributing to gender inequalities. To continue advancing gender equality in dental academia and research, efforts should be geared toward the collection and public dissemination of data on gender-specific distributions. Such evidence-driven information will guide the selection of future strategies and best practices for promoting gender equity in the dental workforce, which provides a major pipeline of researchers and scholars for the dental profession.

Dental insurance, dental care utilization, and perceived unmet dental needs in women living with HIV: Results from the Women's Interagency HIV Study

OBJECTIVES

Dental care is the most commonly cited unmet health-care service due to cost. Previous research has highlighted the unmet dental needs of people living with HIV (PLWH). Understanding associations among dental insurance availability, dental care utilization, and the presence of unmet dental needs among PLWH is a public health priority.

METHODS

Oral health surveys were collected cross-sectionally (April-October 2016) among 1,442 women living with HIV (WLWH) in the Women's Interagency HIV Study. Logistic regression models were used to analyze the association between having versus not having dental insurance by type (Ryan White, private, Medicaid/Medicare) and two primary outcomes: a) typical frequency of dental visits (at least annually, less than annually) and b) reporting an unmet dental need in the past 6 months.

RESULTS

All dental insurance types were associated with higher odds of receiving annual dental care and, for those with either Medicare/Medicaid or private insurance, lower odds of having an unmet dental need. When WLWH were asked to describe their oral health, poor self-reported condition was associated with both an unmet dental need (odds ratio [OR]: 4.52, 95 percent Confidence Interval [CI] [3.29-6.20]) and lower odds of annual dental care utilization (OR: 0.44, 95 percent CI [0.34-0.57]). Self-reported depressive symptom burden was also linked to having an unmet dental need (OR: 2.10, 95 percent CI [1.46-3.01]).

CONCLUSIONS

Dental insurance coverage increases dental care utilization and is associated with better oral health among WLWH. In the era of health-care reform, dental insurance coverage may be instrumental for enhancing treatment outcomes.

A Randomized, Placebo-Controlled Trial of the Quadrivalent Human Papillomavirus Vaccine in Human Immunodeficiency Virus-Infected Adults Aged 27 Years or Older: AIDS Clinical Trials Group Protocol A5298

Background

Adults living with human immunodeficiency virus (HIV) are at increased risk for anal and oropharyngeal cancer caused by human papillomavirus (HPV). The efficacy of HPV vaccines in this population is unknown.

Methods

In this phase 3, double-blind, randomized, controlled trial, we assigned HIV-infected adults aged ≥27 years to the quadrivalent HPV (types 6, 11, 16, 18) vaccine or placebo (1:1) stratified by sex and presence of anal high-grade squamous intraepithelial lesions on biopsy (bHSIL). The primary endpoint was vaccine efficacy against incident persistent anal infection with quadrivalent vaccine types or single detection at the final visit that were not present at baseline. Secondary endpoints included vaccine efficacy for anal bHSIL after week 52, persistent oral HPV infection.

Results

A total of 575 participants were randomized. The Data and Safety Monitoring Board stopped the study early due to futility. Vaccine efficacy was 22% (95.1% confidence interval [CI], -31%, 53%) for prevention of persistent anal infection or single detection at the final visit, 0% (95% CI -44%, 31%) for improving bHSIL outcomes and 88% (95.1% CI 2%, 98%) for preventing persistent oral HPV infection, but was 32% (95.1% CI -80%, 74%) for 6-month persistent oral HPV infection or single detection at the final visit.

Conclusions

These results do not support HPV vaccination of HIV-infected adults aged ≥27 years to prevent new anal HPV infections or to improve anal HSIL outcomes. However, our data suggest a role for prevention of oral HPV infections, but this finding should be confirmed in future studies.

Clinical Trials Registration

NCT01461096.

Impact of periodontal intervention on local inflammation, periodontitis, and HIV outcomes

OBJECTIVE

The aim of this study was to determine active periodontal disease status in HIV and to determine the impact of periodontal disease resolution on HIV status.

METHODS

In this longitudinal cohort study, 73 HIV-positive subjects received comprehensive dental care. AAP, CDC/AAP, and BGI case definitions determined periodontal classification. Likelihood and frequency of moderate/severe periodontal disease were assessed based on demographic variables. The influence of periodontal intervention was assessed at baseline, 12, and 24 months. IL-6 was measured in a subset of subjects.

RESULTS

Of the periodontal classifications, BGI demonstrated the highest percentage category improvement with the intervention (>50%). Moderate/severe periodontitis was positively associated with HIV regardless of race, smoking status, gender, income level, and age, and was associated with increased IL-6. At baseline, the majority of subjects had severe periodontal disease regardless of ART status. Subjects with suppressed viral load at baseline demonstrated a significant improvement in BGI classification (P = 0.026), increased CD4 counts (P = 0.027), and decreased IL-6 levels (P = 0.03).

CONCLUSIONS

Periodontal inflammation was prevalent regardless of ART status. In virologically suppressed subjects, the intervention decreased periodontitis with a concomitant IL-6 decrease and CD4 increase. These findings suggest a relationship between periodontal inflammation, oral microbial translocation, and HIV status.

Innate immunity in HIV-1 infection: epithelial and non-specific host factors of mucosal immunity- a workshop report

The interplay between HIV-1 and epithelial cells represents a critical aspect in mucosal HIV-1 transmission. Epithelial cells lining the oral cavity cover subepithelial tissues, which contain virus-susceptible host cells including CD4(+) T lymphocytes, monocytes/macrophages, and dendritic cells. Oral epithelia are among the sites of first exposure to both cell-free and cell-associated virus HIV-1 through breast-feeding and oral-genital contact. However, oral mucosa is considered to be naturally resistant to HIV-1 transmission. Oral epithelial cells have been shown to play a crucial role in innate host defense. Nevertheless, it is not clear to what degree these local innate immune factors contribute to HIV-1 resistance of the oral mucosa. This review paper addressed the following issues that were discussed at the 7th World Workshop on Oral Health and Disease in AIDS held in Hyderabad, India, during November 6-9, 2014: (i) What is the fate of HIV-1 after interactions with oral epithelial cells?; (ii) What are the keratinocyte and other anti-HIV effector oral factors, and how do they contribute to mucosal protection?; (iii) How can HIV-1 interactions with oral epithelium affect activation and populations of local immune cells?; (iv) How can HIV-1 interactions alter functions of oral epithelial cells?

Hairy leukoplakia; lessons learned: 30-plus years

Well into the fourth decade of the HIV/AIDS pandemic, we can look back on the early years, the initial discoveries, and the broad sweep of the progress of our understanding of the nature, causes, and significance of the oral lesions seen in those infected with the virus. Prominent among these is oral hairy leukoplakia (HL), a previously unknown lesion of the mouth associated with Epstein-Barr virus (EBV) and initially seen only in people with AIDS, in the then-recognized risk groups, or those shown to be HIV positive. Subsequently, it became clear that the distribution of HL extends well beyond the HIV spectrum. In this brief review, we consider the clinical and histological features of HL, discuss how it was discovered, explore its cause, diagnosis, relationship with AIDS, pathogenesis, significance in EBV biology, options for management, and how it changes with HIV/AIDS therapy.

Common Polymorphisms in IFI16 and AIM2 Genes Are Associated With Periodontal Disease

BACKGROUND

The single nucleotide polymorphism (SNP) context of a previously identified periodontitis-associated locus is investigated, and its association with microbial, biologic, and periodontal disease clinical parameters is examined.

METHODS

A 200-kb spanning region of 1q12 previously highlighted in a genome-wide association scan among 4,766 European American individuals (SNP rs1633266) was annotated. Two haplotype blocks were selected. Association of these polymorphisms with data on microbial plaque composition, gingival crevicular fluid (GCF)-interleukin (IL)-1β levels, and clinical parameters of periodontal disease were examined. Descriptive analysis of IFI16 and AIM2 protein expression in gingival tissues from healthy individuals (n = 2) and individuals with chronic periodontitis (n = 2) was done via immunohistochemistry.

RESULTS

The highlighted locus is a 100-kb region containing the interferon γ-inducible protein 16 (IFI16) and absent in melanoma 2 (AIM2) genes. Two haplotype blocks, rs6940 and rs1057028, were significantly associated with increased extent bleeding on probing and levels of microorganisms Porphyromonas gingivalis, Tannerella forsythia, and Campylobacter rectus (P ≤0.05). Haplotype block rs1057028 was also significantly associated with pathogens Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans, increased GCF-IL-1β levels, and extent of probing depth ≥4 mm (P ≤0.05). Prevalence of severe periodontitis (biofilm-gingival interface P3 classification) was positively associated with haplotype block rs1057028. Similar trends were observed for haplotype block rs1057028. IFI16 and AIM2 protein expression was observed in multiple cell types of gingival tissues, including inflammatory cells.

CONCLUSION

This study found IFI16 and AIM2 SNPs associated with higher levels of periodontal microorganisms and an increased percentage of periodontal disease clinical parameters, suggesting the need for functional studies and additional fine-mapping of variants in the 1q12-locus.

Oral EBV and KSHV Infection in HIV

The gamma herpesviruses, Kaposi’s-sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV), are tightly associated with the development of AIDS-associated oral disease and malignancy during immune suppression. The objective of this investigation was to characterize oral infection and pathogenesis in healthy and immune-suppressed individuals. To characterize oral EBV and KSHV infection, we examined throat washings and oral epithelial cells from HIV-positive and HIV-negative individuals. Quantitative/real-time polymerase-chain-reaction (PCR) assays, transmission electronmicroscopy, immunostaining, and sequence analysis were used to identify viral infection. Virus was isolated from throat-wash samples and was used to infect epithelial and lymphoid cell lines. We detected EBV and KSHV in the oral cavity in healthy and immune-suppressed individuals. Viral strain analysis of KSHV K1 in multiple clones from the oral cavities of healthy persons and immunosuppressed patients detected several strains previously detected in KS lesions, with minor strain variation within individuals. Immunoelectron microscopy for multiple viral antigens detected consistent expression of viral proteins and oral epithelial specimens. In oral epithelial cells infected with wild-type KSHV in vitro, the K8.1 glycoprotein associated with lytic KSHV infection was detected in both primary and telomerase immortalized oral epithelial cultures by 24 hours post-infection. Virions were detected, subsequent to infection, by scanning electron microscopy. Oral epithelial cells were also infected in vitro with wild-type EBV originating from throat washes. Analysis of these data suggests that, like EBV, KSHV infection is present in the oropharynx of healthy individuals, is transmissible in vitro, and may be transmitted by saliva.

The Association between the History of HIV Diagnosis and Oral Health

Unmet oral care needs are high among people living with human immunodeficiency virus (HIV)/AIDS (PLWH). Oral health care is of increasing importance as life expectancy is being prolonged extensively among PLWH. The benefit of oral health care in relation to time since HIV diagnosis has not previously been assessed. A retrospective multivariable analysis of the Special Project of National Significance Oral Health Initiative observational cohort study ( N = 2,178) was performed to estimate the odds ratios (ORs) of oral health outcomes comparing historically diagnosed subjects (>1 y since HIV diagnosis) to newly diagnosed subjects (≤1 y since HIV diagnosis). ORs were adjusted for age, study site, language, income, last dental care visit, and dental insurance. Historically diagnosed subjects were more likely to report oral problems than newly HIV-diagnosed subjects (OR, 2.10). Historically diagnosed subjects were more likely to require oral surgery (OR, 1.52), restorative treatment (OR, 1.35), endodontic treatment (OR, 1.63), and more than 10 oral clinic visits over the 24-mo study period (OR, 2.02). The crude cumulative 2-y risk of requiring prosthetic (risk difference [RD], 0.21) and endodontic (RD, 0.11) treatment was higher among historically than newly diagnosed subjects, despite no significance postadjustment. Furthermore, poor oral health outcomes were exacerbated among non-highly active antiretroviral therapy users. Summarizing, the authors found that historically diagnosed subjects were more likely to report oral problems and require dental procedures compared with newly diagnosed subjects, suggesting that oral health among PLWH declines over time since HIV diagnosis. Hence, newly diagnosed PLWH may benefit from the implementation of early oral interventions.

Distinct BK polyomavirus non-coding control region (NCCR) variants in oral fluids of HIV- associated Salivary Gland Disease patients

HIV-associated Salivary Gland Disease (HIVSGD) is among the most common salivary gland-associated complications in HIV positive individuals and was associated with the small DNA tumorvirus BK polyomavirus (BKPyV). The BKPyV non-coding control region (NCCR) is the main determinant of viral replication and rearranges readily. This study analyzed the BKPyV NCCR architecture and viral loads of 35 immunosuppressed individuals. Throatwash samples from subjects diagnosed with HIVSGD and urine samples from transplant patients were BKPyV positive and yielded BKPyV NCCR sequences. 94.7% of the BKPyV HIVSGD NCCRs carried a rearranged OPQPQQS block arrangement, suggesting a distinct architecture among this sample set. BKPyV from HIV positive individuals without HIVSGD harbored NCCR block sequences that were distinct from OPQPQQS. Cloned HIVSGD BKPyV isolates displayed active promoters and efficient replication capability in human salivary gland cells. The unique HIVSGD NCCR architecture may represent a potentially significant oral-tropic BKPyV substrain.

Viral infections associated with oral cancers and diseases in the context of HIV: a workshop report

Human herpesviruses (HHVs) and human papillomavirus (HPV) are common in the general population and, in immunocompetent people, are mostly carried asymptomatically. However, once an individual becomes immunocompromised by age, illness or HIV infection these dormant viruses can manifest and produce disease. In HIV-positive patients, there is an increased risk of disease caused by HHVs and HPV infections and cancers caused by the oncoviruses Epstein-Barr Virus, HHV-8 and HPV. This workshop examined four questions regarding the viruses associated with oral cancers and disease in the HIV-positive and -negative populations, the immune response, and biomarkers useful for accurate diagnostics of these infections and their sequalae. Each presenter identified a number of key areas where further research is required.

Human BK Polyomavirus-The Potential for Head and Neck Malignancy and Disease

Members of the human Polyomaviridae family are ubiquitous and pathogenic among immune-compromised individuals. While only Merkel cell polyomavirus (MCPyV) has conclusively been linked to human cancer, all members of the polyomavirus (PyV) family encode the oncoprotein T antigen and may be potentially carcinogenic. Studies focusing on PyV pathogenesis in humans have become more abundant as the number of PyV family members and the list of associated diseases has expanded. BK polyomavirus (BKPyV) in particular has emerged as a new opportunistic pathogen among HIV positive individuals, carrying harmful implications. Increasing evidence links BKPyV to HIV-associated salivary gland disease (HIVSGD). HIVSGD is associated with elevated risk of lymphoma formation and its prevalence has increased among HIV/AIDS patients. Determining the relationship between BKPyV, disease and tumorigenesis among immunosuppressed individuals is necessary and will allow for expanding effective anti-viral treatment and prevention options in the future.

High Accuracy of Common HIV-Related Oral Disease Diagnoses by Non-Oral Health Specialists in the AIDS Clinical Trial Group

Objective

Many studies include oral HIV-related endpoints that may be diagnosed by non-oral-health specialists (non-OHS) like nurses or physicians. Our objective was to assess the accuracy of clinical diagnoses of HIV-related oral lesions made by non-OHS compared to diagnoses made by OHS.

Methods

A5254, a cross-sectional study conducted by the Oral HIV/AIDS Research Alliance within the AIDS Clinical Trial Group, enrolled HIV-1-infected adults participants from six clinical trial units (CTU) in the US (San Francisco, New York, Chapel Hill, Cleveland, Atlanta) and Haiti. CTU examiners (non-OHS) received standardized training on how to perform an oral examination and make clinical diagnoses of specific oral disease endpoints. Diagnoses by calibrated non-OHS were compared to those made by calibrated OHS, and sensitivity and specificity computed.

Results

Among 324 participants, the majority were black (73%), men (66%), and the median CD4+ cell count 138 cells/mm³. The overall frequency of oral mucosal disease diagnosed by OHS was 43% in US sites, and 90% in Haiti. Oral candidiasis (OC) was detected in 153 (47%) by OHS, with erythematous candidiasis (EC) the most common type (39%) followed by pseudomembranous candidiasis (PC; 26%). The highest prevalence of OC (79%) was among participants in Haiti, and among those with CD4+ cell count ≤ 200 cells/mm³ and HIV-1 RNA > 1000 copies/mL (71%). The sensitivity and specificity of OC diagnoses by non-OHS were 90% and 92% (for EC: 81% and 94%; PC: 82% and 95%). Sensitivity and specificity were also high for KS (87% and 94%, respectively), but sensitivity was < 60% for HL and oral warts in all sites combined. The Candida culture confirmation of OC clinical diagnoses (as defined by ≥ 1 colony forming unit per mL of oral/throat rinse) was ≥ 93% for both PC and EC.

Conclusion

Trained non-OHS showed high accuracy of clinical diagnoses of OC in comparison with OHS, suggesting their usefulness in studies in resource-poor settings, but detection of less common lesions may require OHS.

Effect of Leflunomide, Cidofovir and Ciprofloxacin on replication of BKPyV in a salivary gland in vitro culture system

BK polyomavirus (BKPyV) is a known kidney tropic virus that has been detected at high levels in HIV-associated salivary gland disease (HIV-SGD), one of the most important AIDS associated oral lesions. BKPyV has been detected in HIV-SGD patient saliva and replicates in salivary gland cells in vitro. BKPyV antivirals are currently in wide use to guard against BKPyV mediated organ rejection in kidney transplant recipients. The goal of this study was to investigate the inhibitory effects of three such antiviral agents, Ciprofloxacin, Cidofovir, and Leflunomide in BKPyV infected salivary gland cells. Human salivary gland cells, and Vero cells, were infected with BKPyV, treated with antiviral drugs and assessed for BKPyV gene expression and viral replication for up to 5 days post infection. The kinetics of BKPyV replication were different in salivary gland cells compared to kidney cells. Ciprofloxacin and Cidofovir had minimal effect on metabolic activity and host cell DNA replication, however, cell toxicity was detected at the protein level with Leflunomide treatment. Ciprofloxacin decreased BKV T Ag and VP1 mRNA expression by at least 50% in both cell types, and decreased T Ag protein expression at days 3 and 4 post infection. A 2.5-4 log decrease in intracellular DNA replication and a 2-3 log decrease in progeny release were detected with Ciprofloxacin treatment. Cidofovir and Leflunomide also inhibited BKPyV gene expression and DNA replication. The three drugs diminished progeny release by 30-90% and 2- to 6-fold decreases in infectious virus were detected post drug treatment by fluorescence focus assay. Additionally, three clinical BKPyV isolates were assessed for their responses to these agents in vitro. Cidofovir and Leflunomide, but not Ciprofloxacin treatment resulted in statistically significant inhibition of BKPyV progeny release from salivary gland cells infected with HIVSGD BKPyV isolates. All three drugs decreased progeny release from cells infected with a transplant derived viral isolate. In conclusion, treatment of human salivary gland cells with each of the three drugs produced modest decreases in BKPyV genome replication. These data highlight the need for continued studies to discover more effective and less toxic drugs that inhibit BKPyV replication in salivary gland cells.

Correlation of transcription of MALAT-1, a novel noncoding RNA, with deregulated expression of tumor suppressor p53 in small DNA tumor virus models

Although metastasis-associated lung adenocarcinoma transcript (MALAT)-1 is known to be consistently upregulated in several epithelial malignancies, little is known about its function or regulation. We therefore examined the relationship between MALAT-1 expression and candidate modulators such as DNA tumor virus oncoproteins human papillomavirus (HPV)-16 E6 and E7, BK virus T antigen (BKVTAg), mouse polyoma virus middle T antigen (MPVmTAg) and tumor suppressor genes p53 and pRb. Using suppressive subtractive hybridization (SSH) and real-time reverse transcriptase polymerase chain reaction (RT-PCR) assays, MALAT-1 was shown to be increased in viral oncongene-expressing salivary gland biopsies from humans and mice. The results also indicated that MALAT-1 transcripts and promoter activity were increased in vitro when viral oncongene-expressing plasmids were introduced into different cell types. These same viral oncogenes in addition to increasing MALAT-1 transcription have also been shown to inhibit p53 and/or pRb function. In p53 mutant or inactive cell lines MALAT-1 was also shown to be highly upregulated. We hypothesize that there is a correlation between MALAT-1 over-expression and p53 deregulation. In conclusion, we show that disruption of p53, by both polyoma and papilloma oncoproteins appear to play an important role in the up-regulation of MALAT-1. MALAT-1 might therefore represent a biomarker for p53 deregulation within malignancies.

Metabolomics reveals differential levels of oral metabolites in HIV-infected patients: toward novel diagnostic targets

The objective of the current study was to characterize the profile of oral metabolites in HIV-infected patients using metabolomics. Oral wash samples were collected from 12 HIV-infected and 12 healthy individuals (matched for age, sex, and ethnicity), processed, and analyzed by metabolomics. We detected 198 identifiable and 85 nonidentifiable metabolites; 27 identifiable metabolites were differentially present (12 increased, 15 decreased) in HIV-infected patients. Elevated metabolites included p-cresol sulfate, nucleotides (e.g., allantoin), and amino acids (e.g., phenylalanine, tryptophan), whereas decreased oral metabolites included fucose, fumarate, and N-acetylglucosamine. Pathway network analysis revealed the largest multinode network in healthy versus HIV-infected patients to involve carbohydrate biosynthesis and degradation. HIV-infected patients on antiretroviral therapy (ART) showed the largest number (12) of statistically significant metabolite correlation differences compared with healthy controls. Interestingly, the oral phenlyalanine:tyrosine ratio increased in ART-naive HIV-infected patients (mean ± SEM = 2.58 ± 0.87) compared with healthy individuals (1.33 ± 0.10, p = 0.062) or ART-experienced patients (1.78 ± 0.30, p = 0.441). This is the first study to reveal differential levels of oral metabolites in HIV-infected patients compared withj healthy volunteers, and that oral phenlyalanine:tyrosine ratio may be a useful marker for noninvasive monitoring of the immune status during HIV infection.

Detection and quantitation of HPV in genital and oral tissues and fluids by real time PCR

BACKGROUND

Human papillomaviruses (HPVs) remain a serious world health problem due to their association with anogenital/oral cancers and warts. While over 100 HPV types have been identified, a subset is associated with malignancy. HPV16 and 18 are the most prevalent oncogenic types, while HPV6 and 11 are most commonly responsible for anogenital warts. While other quantitative PCR (qPCR) assays detect oncogenic HPV, there is no single tube assay distinguishing the most frequent oncogenic types and the most common types found in warts.

RESULTS

A Sybr Green-based qPCR assay was developed utilizing degenerate primers to the highly conserved HPV E1 theoretically detecting any HPV type. A single tube multiplex qPCR assay was also developed using type-specific primer pairs and TaqMan probes that allowed for detection and quantitation of HPV6,11,16,18. Each HPV type was detected over a range from 2 x 10(1) to 2 x 10(6)copies/reaction providing a reliable method of quantitating type-specific HPV in 140 anogenital/cutaneous/oral benign and malignant specimens. 35 oncogenic and low risk alpha genus HPV types were detected. Concordance was detected in previously typed specimens. Comparisons to the gold standard detected an overall sensitivity of 89% (95% CI: 77% - 96%) and specificity of 90% (95%CI: 52% - 98%).

CONCLUSION

There was good agreement between the ability of the qPCR assays described here to identify HPV types in malignancies previously typed using standard methods. These novel qPCR assays will allow rapid detection and quantitation of HPVs to assess their role in viral pathogenesis.

Concurrent human papillomavirus-associated tonsillar carcinoma in 2 couples

We describe 2 nonsmoking, nondrinking couples who developed human papillomavirus (HPV)-associated tonsillar cancer within 12 months of each other. After histopathologic evaluation, HPV L1, E2, E6, and LCR regions were amplified, and phylogenetic analysis of amplimers was determined. Quantitative polymerase chain reaction targeting HPV-16/18 L1 and E7 regions and P16 immunohistochemistry were performed. Tissues were HPV-16 positive, with distinct intercouple nucleotide differences and multiple unique intracouple similarities identified. Diffuse nuclear P16 expression was detected in tumor cells. This report demonstrates matching HPV-16 strains in 2 couples with concurrent development of tonsillar carcinoma who did not have other risk factors, revealing the potential infectious nature of oropharyngeal cancer.

BK virus has tropism for human salivary gland cells in vitro: implications for transmission

BACKGROUND

In this study, it was determined that BKV is shed in saliva and an in vitro model system was developed whereby BKV can productively infect both submandibular (HSG) and parotid (HSY) salivary gland cell lines.

RESULTS

BKV was detected in oral fluids using quantitative real-time PCR (QRTPCR). BKV infection was determined using quantitative RT-PCR, immunofluorescence and immunoblotting assays. The infectivity of BKV was inhibited by pre-incubation of the virus with gangliosides that saturated the major capsid protein, VP1, halting receptor mediated BKV entry into salivary gland cells. Examination of infected cultures by transmission electron microscopy revealed 45-50 nm BK virions clearly visible within the cells. Subsequent to infection, encapsidated BK virus was detected in the supernatant.

CONCLUSION

We thus demonstrated that BKV was detected in oral fluids and that BK infection and replication occur in vitro in salivary gland cells. These data collectively suggest the potential for BKV oral route of transmission and oral pathogenesis.

Oropharyngeal carcinoma in non-smokers and non-drinkers: a role for HPV

Incidence of oropharyngeal squamous cell carcinoma (OSCC) increased 3% annually from 1973 to 2001. OSCC's can be attributed to tobacco and alcohol, but 25% are unlinked to typical risks. Case-control studies on HPV detection in non-smoking/non-drinking (NS/ND) OSCC patients have not previously been performed. The primary objective of this study was to determine whether high-risk HPV infection was significantly associated with development of oral squamous malignancy in non-smokers/non-drinkers. A chart review of 802 OSCC patients from the UNC Pathology Archives (1995-2006) yielded 40 non-smoker/non-drinker subjects. Utilizing a case-control design, 18 cancer cases and 22 benign biopsy controls were consecutively identified. Biopsy tissue was subjected to (i) HPV-L1 consensus PCR and sequencing (ii) real-time PCR. Chi-square and logistic regression analysis was employed. Logistic regression analysis determined that cases were 6.1 (OR 95% CI, 1.3-28) times more likely to have HPV infection in their tumors than controls. High-risk HPV-DNA was readily detected in the tonsils and base of tongue (oropharynx) of 14/18 cases and 6/22 controls by both consensus and real-time PCR. Of high-risk HPV containing lesions, 85% (17/20) originated in the oropharynx (chi-square, p=0.03). High risk HPV was also detected in benign biopsies of the oropharynx in 30% (3/10) of individuals who had a previous oral cancer (chi-square, p=0.006). The infectious nature of OSCC in NS/ND was revealed by consistent detection of HPV, suggesting HPV's potential role in transforming oral epithelium, providing further evidence of the need to screen the oropharynx for HPV in NS/ND.

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.

A dynamic model for induced reactivation of latent virus

We develop a deterministic mathematical model to describe reactivation of latent virus by chemical inducers. This model is applied to the reactivation of latent KSHV in BCBL-1 cell cultures with butyrate as the inducing agent. Parameters for the model are first estimated from known properties of the exponentially growing, uninduced cell cultures. Additional parameters that are necessary to describe induction are determined from fits to experimental data from the literature. Our initial model provides good agreement with two independent sets of experimental data, but also points to the need for a new class of experiments which are required for further understanding of the underlying mechanisms.

Stability and release of antiviral drugs from ethylene vinyl acetate (EVA) copolymer

The use of polymer based drug delivery systems in dentistry is a relatively new area of research with the exception of the inhibition of secondary caries by the release of fluoride ions from polyalkenoate cements and their predecessors silicate cements. The present study was to test on orally biocompatible material, ethylene vinyl acetate copolymer (EVA), for release of antiviral drugs at oral therapeutic levels over extended periods of time. We also determined their stability during film casting and release. Materials studied include gancyclovir (GCY), acyclovir (ACY), dichloromethane (DCM), and ethylene vinyl acetate (EVA). The square films (3 x 3 x 0.1 cm) were prepared from the dry sheet obtained by solvent evaporation of polymer casting solutions. These solutions were made of EVA and the drug (40:1) in 70 ml of dichloromethane at 38 degrees C. Then drug release characteristics from the drug loaded films were examined at 37 degrees C for a minimum of 14 days in 10 ml medium (ddwater) replaced daily. Kinetics of drug release were followed by spectral measurements using previously determined lambda(max) values (GCY = 250 nm; ACY = 253 nm). A minimum of three samples was tested and reproducible results were obtained. Drug stability (ACY) during film casting and its release was determined using 1H NMR spectrometer (Bruker DRX-500 and 400). Rate of drug release was determined from the part of the curve (rate vs. time) after the onset of the "burst." Although GCY has a larger molecular weight (255) than ACY (225), GCY exhibited about three times higher rate of release than ACY. This difference in rate values may be explained due to its relatively greater solubility in EVA, facilitating faster diffusion of the molecules through the channels present in EVA. This is consistent with the observation that the rate at which drug molecules diffuse through the channels of the polymer, can be increased by decreasing the molecular weight. In the case of ACY, the molecules may be undergoing molecular associations, perhaps dimerization or trimerization in addition to its lower solubility in EVA. The diffusion of ACY tends to be slower under these circumstances compared to GCY resulting in lower rate value than in the case of GCY. Biological studies revealed that ACY exhibited a remarkable decrease in a number of viral organisms present in virus infected cell culture system using real-time polymerase chain reaction (RT-PCR). NMR analysis indicates that the chemical structure of the drug remains stable during film casting process and release.

Interferon regulatory factor 7 is negatively regulated by the Epstein-Barr virus immediate-early gene, BZLF-1

Virus infection stimulates potent antiviral responses; specifically, Epstein-Barr virus (EBV) infection induces and activates interferon regulatory factor 7 (IRF-7), which is essential for production of alpha/beta interferons (IFN-alpha/beta) and upregulates expression of Tap-2. Here we present evidence that during cytolytic viral replication the immediate-early EBV protein BZLF-1 counteracts effects of IRF-7 that are central to host antiviral responses. We initiated these studies by examining IRF-7 protein expression in vivo in lesions of hairy leukoplakia (HLP) in which there is abundant EBV replication but the expected inflammatory infiltrate is absent. This absence might predict that factors involved in the antiviral response are absent or inactive. First, we detected significant levels of IRF-7 in the nucleus, as well as in the cytoplasm, of cells in HLP lesions. IRF-7 activity in cell lines during cytolytic viral replication was examined by assay of the IRF-7-responsive promoters, IFN-alpha4, IFN-beta, and Tap-2, as well as of an IFN-stimulated response element (ISRE)-containing reporter construct. These reporter constructs showed consistent reduction of activity during lytic replication. Both endogenous and transiently expressed IRF-7 and EBV BZLF-1 proteins physically associate in cell culture, although BZLF-1 had no effect on the nuclear localization of IRF-7. However, IRF-7-dependent activity of the IFN-alpha4, IFN-beta, and Tap-2 promoters, as well as an ISRE promoter construct, was inhibited by BZLF-1. This inhibition occurred in the absence of other EBV proteins and was independent of IFN signaling. Expression of BZLF-1 also inhibited activation of IRF-7 by double-stranded RNA, as well as the activity of a constitutively active mutant form of IRF-7. Negative regulation of IRF-7 by BZLF-1 required the activation domain but not the DNA-binding domain of BZLF-1. Thus, EBV may subvert cellular antiviral responses and immune detection by blocking the activation of IFN-alpha4, IFN-beta, and Tap-2 by IRF-7 through the medium of BZLF-1 as a negative regulator.

The C-mer gene is induced by Epstein-Barr virus immediate-early protein BRLF1

BRLF1 (R) is one of two Epstein-Barr virus (EBV) immediate-early proteins that mediate the switch from the latent to the lytic form of viral replication. In this report, we show that R induces expression of the cellular C-mer gene in a variety of cell lines. C-mer expression was detected in lymphoblastoid cells immortalized with wild-type EBV but not in lymphoblastoid cells immortalized with an EBV that had BRLF1 deleted. Oral hairy leukoplakia tongue tissue, which contains the lytic form of EBV replication, also has enhanced C-mer expression. C-mer is a receptor tyrosine kinase activated by the ligand Gas6. C-mer is required for phagocytosis of apoptotic debris by monocytes/macrophages and retinal pigment epithelial cells and is capable of producing an antiapoptotic signal. Modulation of the C-mer signal transduction cascade by a variety of different approaches did not alter the ability of R to induce lytic EBV gene transcription. Therefore, C-mer activation may be important for some other aspect of lytic EBV infection.

Fatty acid synthase expression is induced by the Epstein-Barr virus immediate-early protein BRLF1 and is required for lytic viral gene expression

The Epstein-Barr virus (EBV) immediate-early (IE) protein BRLF1 (R) is a transcription factor that induces the lytic form of EBV infection. R activates certain early viral promoters through a direct binding mechanism but induces transcription of the other EBV IE gene, BZLF1 (Z), indirectly through cellular factors binding to a CRE motif in the Z promoter (Zp). Here we demonstrate that R activates expression of the fatty acid synthase (FAS) cellular gene through a p38 stress mitogen-activated protein kinase-dependent mechanism. B-cell receptor engagement of Akata cells also increases FAS expression. The FAS gene product is required for de novo synthesis of the palmitate fatty acid, and high-level FAS expression is normally limited to liver, brain, lung, and adipose tissue. We show that human epithelial tongue cells lytically infected with EBV (from oral hairy leukoplakia lesions) express much more FAS than uninfected cells. Two specific FAS inhibitors, cerulenin and C75, prevent R activation of IE (Z) and early (BMRF1) lytic EBV proteins in Jijoye cells. In addition, cerulenin and C75 dramatically attenuate IE and early lytic gene expression after B-cell receptor engagement in Akata cells and constitutive lytic viral gene expression in EBV-positive AGS cells. However, FAS inhibitors do not reduce lytic viral gene expression induced by a vector in which the Z gene product is driven by a strong heterologous promoter. In addition, FAS inhibitors do not reduce R activation of a naked DNA reporter gene construct driven by the Z promoter (Zp). These results suggest that cellular FAS activity is important for induction of Z transcription from the intact latent EBV genome, perhaps reflecting the involvement of lipid-derived signaling pathways or palmitoylated proteins. Furthermore, using FAS inhibitors may be a completely novel approach for blocking the lytic form of EBV replication.

Wild-type Kaposi's sarcoma-associated herpesvirus isolated from the oropharynx of immune-competent individuals has tropism for cultured oral epithelial cells

Based on the observation that wild-type Kaposi's sarcoma-associated herpesvirus (KSHV) DNA can be detected in the oral cavity of healthy, immunocompetent individuals, we hypothesized that epithelial cells could be infected in vitro by wild-type (WT) KSHV isolated from immunocompetent individuals. Primary oral epithelial (P-EPI) cells and telomerase-immortalized oral epithelial cells were generated from human gingival tissue and were then infected in vitro with WT KSHV isolated from throat wash samples. Markers of lytic and latent KSHV infection were detected in cultures by 24 h postinfection by immunofluorescence confocal microscopic assays. The infectivity of the WT and BCBL virus was blocked by neutralizing antibodies against KSHV gB. The presence of KSHV DNA in these cells was confirmed by real-time PCR amplification of different regions of the viral genome. The significant in vitro viral replication that had occurred was inhibited by ganciclovir and by neutralizing antibodies against gB. When infected cultures were examined by scanning electron microscopy, thousands of KSHV particles were clearly visible across the surfaces of P-EPI cells. The detection of enveloped particles indicated that the infectious cycle had proceeded through assembly and egress. We thus demonstrated that oral WT KSHV isolated from immunocompetent individuals was able to infect and replicate in vitro in a relevant primary cell type. Furthermore, our results provide compelling evidence for KSHV transmission within infected oral epithelial cells derived from healthy, immunocompetent populations.

Intracellular localization of the Epstein-Barr virus BFRF1 gene product in lymphoid cell lines and oral hairy leukoplakia lesions

A novel protein encoded by the BFRF1 gene of the Epstein-Barr virus was identified recently [Farina et al. (2000) J Virol 74:3235-3244], which is antigenic "in vivo" and expressed early in the viral replicative cycle. In the present study, its subcellular localization was examined in greater detail comparing Epstein-Barr virus (EBV) induced producing and nonproducing cell lines by immunofluorescence: in 12-0-tetradecanoyl phorbol-13-acetate (TPA)-induced Raji and B95-8 cells, as well as in anti-IgG-stimulated Akata cells, the protein appeared to be localized over the cell nuclear membrane. A similar nuclear membrane localization was observed in epithelial cells of oral hairy leukoplakia, a pathological manifestation of permissive EBV infection. In contrast, upon transfection of BFRF1 in the EBV-negative Burkitt's lymphoma cell line DG75, the protein was localized predominantly over the plasma membrane. The membrane localization was abolished when DG75 cells were transfected with a C-terminal deletion mutant of BFRF1 lacking the transmembrane domain. Because induced Raji cells do not produce virus, the above observations indicate that the nuclear membrane localization is not associated with viral production, but requires the expression of EBV genes, and suggest that additional proteins, expressed early during viral lytic infection, might be necessary to target the protein to the nuclear membrane. Immunogold electron microscopy on ultrathin cryosections of induced B95-8 cells showed that BFRF1 on the nuclear membranes was concentrated over multilayered domains representing areas of active viral replication or at the sites of viral budding, suggesting that BFRF1 is involved in the process of viral assembly.

Autologous Epstein-Barr virus (EBV)-specific cytotoxic T cells for the treatment of persistent active EBV infection

Chronic active Epstein-Barr virus (CAEBV) infection syndrome is a heterogeneous EBV-related disorder characterized by chronic fatigue, fever, lymphadenopathy, and/or hepatosplenomegaly, associated with abnormal patterns of antibody to EBV. CAEBV can range from disabling mild/moderate forms to rapidly lethal disorders. Even patients with mild/moderate disease frequently suffer adverse effects from long-term anti-inflammatory agents and have a quality of life that progressively deteriorates. It is still unknown why these individuals are unable to produce an effective immune response to control EBV, and no effective treatment is currently available. Since ex vivo-expanded EBV-specific cytotoxic T lymphocytes (EBV-CTLs) can safely restore EBV-specific cellular immune responses in immunodeficient patients, we assessed the possibility that adoptive immunotherapy might also effectively treat CAEBV infection. Following stimulation with irradiated EBV-transformed lymphoblastoid cell lines (LCLs), EBV-CTLs were successfully generated from 8 of 8 patients with the mild/moderate form of CAEBV infection. These CTLs were predominantly CD3(+) CD8(+) cells and produced specific killing of the autologous LCLs. There were 5 patients with 1- to 12-year histories of disease who were treated with 1 to 4 injections of EBV-CTLs. Following infusion, there was resolution of fatigue and malaise, disappearance of fever, and regression of lymphadenopathy and splenomegaly. The pattern and titers of anti-EBV antibodies also normalized. No toxicity was observed. There were 4 patients who did not show any relapse of disease within 6 to 36 months follow-up; one patient had recurrence of fatigue and myalgia one year after CTL infusion. We suggest that adoptive immunotherapy with autologous EBV-CTLs may represent a safe and feasible alternative treatment for patients affected with mild/moderate CAEBV infection and that this approach should be evaluated in the more severe forms of the disease.

Mechanisms of expression of HHV8, EBV and HPV in selected HIV-associated oral lesions

Opportunistic DNA viruses, particularly members of the herpesvirus family, are frequently the aetiological agents of HIV-associated oral lesions. Oral lesions common to the early phase of the AIDS epidemic, including Kaposi's sarcoma (KS), oral aphthous ulceration, AIDS-associated oral lymphoma, and oral hairy leukoplakia (OHL), have been tested for the prevalence of Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV). While EBV DNA is detected by PCR in all of these lesions, abundant viral replication can only be detected in OHL. In OHL, a novel state of EBV infection has been discovered with concurrent expression of replicative and transforming proteins, with all of these proteins contributing to the development of the lesion. Activation of signalling pathways and up-regulation of the viral receptor, proliferative and antiapoptotic genes by these proteins induce several of the histological features common to OHL, such as acanthosis and hyperproliferation. In contrast to other permissive herpesvirus infections, expression of EBV transforming proteins within the permissively infected OHL tissue enables epithelial cell survival and may enhance viral replication. Detection of KSHV in these HIV-infected individuals has been localized only to their saliva. Replicative and latent KSHV gene products have been detected in association with the development of oral KS lesions. EBV, but not human cytomegalovirus (HCMV), has been detected by PCR in minor salivary gland biopsies of HIV-associated salivary gland disease. Human papillomaviruses (HPV) are associated with oral warts in HIV-positive individuals; a diagnosis that appears to be increasing in frequency in the era of highly active antiretroviral therapy. To date, there appears to be little increase in the incidence of HPV-associated oral cancer. The mechanisms of interaction between HIV and HPV are not fully understood. Expression of viral gene products is clearly important and necessary for the development of multiple AIDS-associated oral lesions.

Identification of Epstein-Barr virus strain variants in hairy leukoplakia and peripheral blood by use of a heteroduplex tracking assay

Epstein-Barr virus (EBV) strains can be distinguished by specific sequence variations in the LMP1 gene. In this study, a heteroduplex tracking assay (HTA) specific for LMP1 was developed to precisely identify the prototypic undeleted strain B958, other undeleted strains (Ch2, AL, NC, and Med-), and strains with the 30-bp deletion (Med+ and Ch1). This technique also provides an estimate of the relative abundance of strains in patient samples. In this study, EBV strains were identified in 25 hairy leukoplakia (HLP) biopsies and six matched peripheral blood samples and throat washes with the LMP1-HTA. To investigate the relationship of the virus found in the peripheral blood to that in the HLP lesion, the strain variants in the peripheral blood B lymphocytes and those present within the epithelial cells in the HLP lesion and in throat washes were identified. In many of the subjects, compartmental differences in the EBV strain profiles in the oral cavity and peripheral blood were readily apparent. The throat wash specimens usually had a strain profile similar to that within the corresponding HLP sample, which was distinct from the strain profile detected in the peripheral blood. These analyses reveal that the nature of EBV infection can be very dynamic, with changes in relative strain abundance over time as well as the appearance of new strains. The patterns of abundance in the blood and oral cavity provide evidence for compartmentalization and for the transmission of strains between the blood and oropharynx.