Deficiency in Ever2 does not increase susceptibility of mice to pathogenesis by the mouse papillomavirus, MmuPV1.

Epidermodysplasia verruciformis (EV) is a rare genetic skin disorder that is characterized by the development of papillomavirus-induced skin lesions that can progress to squamous cell carcinoma (SCC). Certain high-risk, cutaneous ß-genus human papillomaviruses (ß-HPVs), in particular HPV5 and HPV8, are associated with inducing EV in individuals who have a homozygous mutation in one of three genes tied to this disease: EVER1, EVER2, or CIB1. EVER1 and EVER2 are also known as TMC6 and TMC8, respectively. Little is known about the biochemical activities of EVER gene products or their roles in facilitating EV in conjunction with ß-HPV infection. To investigate the potential effect of EVER genes on papillomavirus infection, we pursued in vivo infection studies by infecting Ever2-null mice with mouse papillomavirus (MmuPV1). MmuPV1 shares characteristics with ß-HPVs including similar genome organization, shared molecular activities of their early, E6 and E7, oncoproteins, the lack of a viral E5 gene, and the capacity to cause skin lesions that can progress to SCC. MmuPV1 infections were conducted both in the presence and absence of UVB irradiation, which is known to increase the risk of MmuPV1-induced pathogenesis. Infection with MmuPV1 induced skin lesions in both wild-type and Ever2-null mice with and without UVB. Many lesions in both genotypes progressed to malignancy, and the disease severity did not differ between Ever2-null and wild-type mice. However, somewhat surprisingly, lesion growth and viral transcription was decreased, and lesion regression was increased in Ever2-null mice compared with wild-type mice. These studies demonstrate that Ever2-null mice infected with MmuPV1 do not exhibit the same phenotype as human EV patients infected with ß-HPVs.IMPORTANCEHumans with homozygous mutations in the EVER2 gene develop epidermodysplasia verruciformis (EV), a disease characterized by predisposition to persistent ß-genus human papillomavirus (ß-HPV) skin infections, which can progress to skin cancer. To investigate how EVER2 confers protection from papillomaviruses, we infected the skin of homozygous Ever2-null mice with mouse papillomavirus MmuPV1. Like in humans with EV, infected Ever2-null mice developed skin lesions that could progress to cancer. Unlike in humans with EV, lesions in these Ever2-null mice grew more slowly and regressed more frequently than in wild-type mice. MmuPV1 transcription was higher in wild-type mice than in Ever2-null mice, indicating that mouse EVER2 does not confer protection from papillomaviruses. These findings suggest that there are functional differences between MmuPV1 and ß-HPVs and/or between mouse and human EVER2.

Betapapillomavirus natural history and co-detection with alphapapillomavirus in cervical samples of adult women.

Human papillomaviruses (HPV) of the genus Betapapillomavirus can infect both cutaneous and mucosal sites, but research on their natural history at mucosal sites remains scarce. We examined the risk factors and co-detection patterns of HPVs of the Betapapillomavirus and Alphapapillomavirus genera in cervical samples of the Ludwig-McGill cohort study. We assessed a subset of 505 women from the Ludwig-McGill cohort study from São Paulo, Brazil. Cervical samples over the first year of follow-up were tested for DNA of over 40 alphapapillomavirus types and 43 betapapillomavirus types using a type-specific multiplex genotyping polymerase chain reaction assay. We assessed the risk factors for prevalent and incident betapapillomavirus type detection, and whether types were detected more frequently together than expected assuming independence using permutation tests, logistic regression, and Cox regression. We observed significant within-genus clustering but not cross-genus clustering. Multiple betapapillomavirus types were co-detected in the same sample 2.24 (95% confidence interval [CI]: 1.65-3.29) times more frequently than expected. Conversely, co-detections of alphapapillomavirus and betapapillomavirus types in the same sample occurred only 0.64 (95% CI: 0.51-0.83) times as often as expected under independence. In prospective analyses, positivity to one HPV genus was associated with a nonsignificant lower incidence of detection of types in the other genus. Lifetime number of sex partners and new sex partner acquisition were associated with lower risks of prevalent and incident betapapillomavirus detection. Betapapillomaviruses are commonly found in the cervicovaginal tract. Results suggest potentially different mechanisms of transmission for betapapillomavirus genital infections other than vaginal sex.

Vaccination with human alphapapillomavirus-derived L2 multimer protects against human betapapillomavirus challenge, including in epidermodysplasia verruciformis model mice.

Human alphapapillomaviruses (αHPV) infect genital mucosa, and a high-risk subset is a necessary cause of cervical cancer. Licensed L1 virus-like particle (VLP) vaccines offer immunity against the nine most common αHPV associated with cervical cancer and genital warts. However, vaccination with an αHPV L2-based multimer vaccine, α11-88x5, protected mice and rabbits from vaginal and skin challenge with diverse αHPV types. While generally clinically inapparent, human betapapillomaviruses (ßHPV) are possibly associated with cutaneous squamous cell carcinoma (CSCC) in epidermodysplasia verruciformis (EV) and immunocompromised patients. Here we show that α11-88x5 vaccination protected wild type and EV model mice against HPV5 challenge. Passive transfer of antiserum conferred protection independently of Fc receptors (FcR) or Gr-1+ phagocytes. Antisera demonstrated robust antibody titers against ten ßHPV by L1/L2 VLP ELISA and neutralized and protected against challenge by 3 additional ßHPV (HPV49/76/96). Thus, unlike the licensed vaccines, α11-88x5 vaccination elicits broad immunity against αHPV and ßHPV.

Human Beta Papillomavirus Type 8 E1 and E2 Proteins Suppress the Activation of the RIG-I-Like Receptor MDA5.

Persistent infections of the skin with the human papillomavirus of genus beta (ß-HPV) in immunocompetent individuals are asymptomatic, but in immunosuppressed patients, ß-HPV infections exhibit much higher viral loads on the skin and are associated with an increased risk of skin cancer. Unlike with HPV16, a high-risk α-HPV, the impact of ß-HPV early genes on the innate immune sensing of viral nucleic acids has not been studied. Here, we used primary skin keratinocytes and U2OS cells expressing HPV8 or distinct HPV8 early genes and well-defined ligands of the nucleic-acid-sensing receptors RIG-I, MDA5, TLR3, and STING to analyze a potential functional interaction. We found that primary skin keratinocytes and U2OS cells expressed RIG-I, MDA5, TLR3, and STING, but not TLR7, TLR8, or TLR9. While HPV16-E6 downregulated the expression of RIG-I, MDA5, TLR3, and STING and, in conjunction with HPV16-E7, effectively suppressed type I IFN in response to MDA5 activation, the presence of HPV8 early genes showed little effect on the expression of these immune receptors, except for HPV8-E2, which was associated with an elevated expression of TLR3. Nevertheless, whole HPV8 genome expression, as well as the selective expression of HPV8-E1 or HPV8-E2, was found to suppress MDA5-induced type I IFN and the proinflammatory cytokine IL-6. Furthermore, RNA isolated from HPV8-E2 expressing primary human keratinocytes, but not control cells, stimulated a type I IFN response in peripheral blood mononuclear cells, indicating that the expression of HPV8-E2 in keratinocytes leads to the formation of stimulatory RNA ligands that require the active suppression of immune recognition. These results identify HPV8-E1 and HPV8-E2 as viral proteins that are responsible for the immune escape of ß-HPV from the innate recognition of viral nucleic acids, a mechanism that may be necessary for establishing persistent ß-HPV infections.

Beta-Genus Human Papillomavirus 8 E6 Destabilizes the Host Genome by Promoting p300 Degradation.

The beta genus of human papillomaviruses infects cutaneous keratinocytes. Their replication depends on actively proliferating cells and, thus, they conflict with the cellular response to the DNA damage frequently encountered by these cells. This review focus on one of these viruses (HPV8) that counters the cellular response to damaged DNA and mitotic errors by expressing a protein (HPV8 E6) that destabilizes a histone acetyltransferase, p300. The loss of p300 results in broad dysregulation of cell signaling that decreases genome stability. In addition to discussing phenotypes caused by p300 destabilization, the review contains a discussion of the extent to which E6 from other ß-HPVs destabilizes p300, and provides a discussion on dissecting HPV8 E6 biology using mutants.

ß-HPV 8E6 combined with TERT expression promotes long-term proliferation and genome instability after cytokinesis failure.

Human papillomavirus (HPV) is a family of viruses divided into five genera: alpha, beta, gamma, mu, and nu. There is an ongoing discussion about whether beta genus HPVs (ß-HPVs) contribute to cutaneous squamous cell carcinoma (cSCC). The data presented here add to this conversation by determining how a ß-HPV E6 protein (ß-HPV 8E6) alters the cellular response to cytokinesis failure. Specifically, cells were observed after cytokinesis failure was induced by dihydrocytochalasin B (H2CB). ß-HPV 8E6 attenuated the immediate toxicity associated with H2CB but did not promote long-term proliferation after H2CB. Immortalization by telomerase reverse transcriptase (TERT) activation also rarely allowed cells to sustain proliferation after H2CB exposure. In contrast, TERT expression combined with ß-HPV 8E6 expression allowed cells to proliferate for months following cytokinesis failure. However, this continued proliferation comes with genome destabilizing consequences. Cells that survived H2CB-induced cytokinesis failure suffered from changes in ploidy.

Comparison and evaluation of three different molecular methods for detection of human Betapapillomaviruses in skin biopsies from patients with nonmelanoma skin cancer and precancerous lesions.

Betapapillomaviruses have been linked to the development of nonmelanoma skin cancers. A great diversity of these viruses in skin specimens requires the use of sensitive and reliable detection methods. There are currently no standardized assays for diagnostic purposes. A combination of several molecular methods has great practical significance and gives the opportunity to broaden the spectrum of detected Beta-HPV types. In the present study, different molecular methods for Beta-HPVs detection and genotyping were used: PCRs with different sets of primers, PCR followed by reverse hybridization and direct sequencing of PCR amplimers; all performed in skin biopsies from lesions and perilesional healthy area of 118 patients with NMSC or precancerous lesions. Beta-HPVs were detected in 41% of 261 biopsies examined. The RHA for 25 types of Beta-HPVs showed a significantly higher sensitivity than PCR-based methods and allowed to detect 172 genotypes in 86 samples, including 39 with multiple infections. The most frequently identified types were HPV23, HPV24 and HPV93. HPV5 and HPV8, considered high-risk carcinogen types, were detected only in a small percentage of samples. Direct sequencing confirmed the presence of Beta-HPV genotypes from outside of RHA panel in the analysed biopsies. This allowed detecting thirty-two additional genotypes in 5 samples, that were positive only in RHA with the universal probe, which failed to identify the virus genotypes. Our findings confirmed the need to apply different methods to detect Beta-HPV infections.

The Role of Beta HPV Types and HPV-Associated Inflammatory Processes in Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is a common form of skin cancer with a complex but not fully understood pathogenesis. Recent research suggests the role of beta human papillomavirus (HPV) types and HPV-associated inflammatory processes in cSCC development. Beta HPV types are components of the normal flora; however, under the influence of certain cofactors, the virus may trigger a malignant process. Dysregulation of the immune system (chronic inflammation and immunosuppression), environmental factors (ultraviolet radiation), and genetic factors are the most important cofactors involved in beta HPV-related carcinogenesis. In addition, the oncoproteins E6 and E7 of beta HPV types differ biochemically from their counterparts in the structure of alpha HPV types, resulting in different mechanisms of action in carcinogenesis. The aim of our manuscript is to present an updated point of view on the involvement of beta HPV types in cSCC pathogenesis.

Presence of human papillomavirus DNA in voriconazole-associated cutaneous squamous cell carcinoma.

BACKGROUND: Voriconazole and genus beta human papillomavirus (HPV) are independently associated with the development of photo-exposed cutaneous squamous cell carcinoma (SCC) but have not been evaluated concurrently. The objective of this study is to determine the prevalence and type of detectable HPV DNA in voriconazole-associated SCC. METHODS: SCCs from immunosuppressed patients, in those with and without voriconazole exposure, were evaluated by PCR analysis for HPV DNA and compared to SCC from non-immunosuppressed patients. An additional expanded PCR analysis of all SCC that developed in the voriconazole group was also performed. RESULTS: HPV DNA was detected by PCR in all groups regardless of the immunosuppression status (80.5%) with beta HPV most prevalent (64.3-78.6%). However, immunosuppressed patients were significantly more likely to be infected by beta HPV types 5, 8, 14, 20, and 21 (P-value 0.014), and represented the majority of beta HPV types found in the voriconazole group. CONCLUSIONS: In this retrospective study, beta HPV 5, 8, 14, 20, and 21 were commonly detected in voriconazole-associated SCC. The results indicate a possible role of beta HPV in the pathogenesis of cutaneous SCC in photo-exposed areas. Further studies are needed to establish the role of HPV and voriconazole in the pathogenesis of the lesion.

Cancer susceptibility of beta HPV49 E6 and E7 transgenic mice to 4-nitroquinoline 1-oxide treatment correlates with mutational signatures of tobacco exposure.

We have previously showed that a transgenic (Tg) mouse model with cytokeratin 14 promoter (K14)-driven expression of E6 and E7 from beta-3 HPV49 in the basal layer of the epidermis and of the mucosal epithelia of the digestive tract (K14 HPV49 E6/E7 Tg mice) are highly susceptible to upper digestive tract carcinogenesis upon exposure to 4-nitroquinoline 1-oxide (4NQO). Using whole-exome sequencing, we show that in K14 HPV49 E6/E7 Tg mice, development of 4NQO-induced cancers tightly correlates with the accumulation of somatic mutations in cancer-related genes. The mutational signature in 4NQO-treated mice was similar to the signature observed in humans exposed to tobacco smoking and tobacco chewing. Similar results were obtained with K14 Tg animals expressing mucosal high-risk HPV16 E6 and E7 oncogenes. Thus, beta-3 HPV49 share some functional similarities with HPV16 in Tg animals.

Prevalence and Correlates of ß- and γ-Human Papillomavirus Detection in Oral Samples From Mid-Adult Women.

BACKGROUND: Little is known about the epidemiology of ß and γ human papillomaviruses (HPVs) in oral cavities of healthy women. METHODS: We performed multiplex polymerase chain reaction analysis for detection of 46 ß-HPVs and 51 γ-HPVs in stored oral rinse samples from healthy mid-adult women (age, 30-50 years). A total of 407 women were tested for ß-HPVs, and 310 were tested for γ-HPVs. We used log-binomial regression to identify determinants of ß-HPV and γ-HPV in separate models. Using paired fingernail data from a subset of 184 women, we also evaluated whether fingernail ß-HPV detection was associated with concurrent detection of the same type in the oral cavity. RESULTS: Oral HPV prevalence was 20.6% for ß-HPV and 10.7% for γ-HPV. In multivariate analysis, oral ß-HPV detection was associated with increasing age (adjusted prevalence ratio [aPR] per 5-year difference, 1.37; 95% confidence interval [CI], 1.01-1.86) and a greater lifetime number of oral sex partners (aPR for reporting ≥6 vs 0-5 partners, 2.06; 95% CI, 1.01-4.20). In a separate model, concurrent detection of the same ß-HPV type in fingernails was strongly associated with oral ß-HPV detection (aPR, 31.44; 95% CI, 19.81-49.49). No significant determinants of γ-HPV detection were identified. CONCLUSIONS: Our results suggest a sexual transmission route for ß-HPVs and support the hypothesis that fingers may serve as a source of transmission or autoinoculation of ß-HPVs to the oral cavity.

Prevalence and Epidemiologic Profile of Oral Infection with Alpha, Beta, and Gamma Papillomaviruses in an Asian Chinese Population.

Background: Knowledge of the prevalence of and risk factors for oral human papillomavirus (HPV) infection, especially cutaneous types, is limited. Methods: A population-based study using next-generation sequencing consecutively recruited asymptomatic individuals aged 18-64 years from a proportional sampling of the general population of Hong Kong, according to age groups, gender, and regions of residence. We examined associations of alpha-, beta-, and gamma-HPVs from oral rinse samples with participants' sociodemographics by logistic regression models. Results: The prevalence of oral HPV infection among 1426 ethnic Chinese was 15.5% (95% confidence interval [CI], 13.7%-17.5%), 2.5% (95% CI, 1.8%-3.5%), 11.9% (95% CI, 10.3%-13.6%), and 2.9% (95% CI, 2.1%-3.9%) for any type, alpha-, beta-, and gamma-HPV, respectively. Prevalence of any high-risk HPV was 0.8% (95% CI, 0.4%-1.4%), and that of HPV-16 was 0.4% (95% CI, 0.2%-0.8%). HPV-8 and HPV-98 were the most common beta types detected, while HPV-4 and HPV-SD2R were the most common gamma types. Prevalence of alpha- and beta/gamma-HPV infection showed a similar pattern of increase with age, and was higher in men than women. Smoking, drinking, oral sex, and more sexual partners were associated with alpha-HPV. Teeth brushing before sleep was protective for beta/gamma-HPVs. Discussion: The epidemiologic factors associated with oral infection with alpha-HPVs are different from those of beta/gamma-HPVs, suggesting different modes of acquisition and persistence.

Characterization of a new genotype of Betapapillomavirus HPV 17 through L1, E7, E7 and LCR sequences.

Human papillomavirus (HPV) exhibits epithelial and mucosal tropism. HPV type 17 belongs to the Betapapillomavirus genus and molecular cloning experiments have identified two subtypes (17a and 17b) isolated from epidermodysplasia verruciformis (EV). HPV subtypes are characterized by dissimilarities from 2 to 10% at the nucleotide level from their referenced HPV. The aim of this study was to characterize the L1, E6, E7 and LCR sequences from an isolate, which was recovered from the oral mucosa of an asymptomatic 63 year-old woman. The whole late gene 1 (L1) was amplified using several sets of primers. The complete early genes 6 and 7 (E6, E7) and the long control region (LCR) were amplified using specific primers. Potential binding sites for transcriptional factors within the LCR were also investigated. Within these sets, the DNA sequence was altered at 91 positions (68 in L1, 13 in E6, 8 in E7, and 2 in LCR sequences). L1 analysis showed high dissimilarity compared with the HPV 17 prototype, reaching 4% of nucleotide substitutions and leading to a probable third 17 subtype. The E6 oncoprotein presented the highest modification among the sequences studied, with four amino acid changes in comparison with the prototype isolate. One amino acid was modified at a position 62 (S-T), a zinc-binding domain (CxxC(C)29 CxxC). Our findings provide data on genetic variations seen in this genotype, reaching to dichotomic branching and pointing to an evolutionary process.

Prevalence and correlates of beta human papillomavirus detection in fingernail samples from mid-adult women.

Cutaneous human papillomaviruses (HPVs) have not been evaluated in fingernails from healthy individuals. To determine prevalence and correlates of ß-HPVs in fingernails from healthy mid-adult women, we tested archived samples collected from 2011 to 2012 using a multiplex PCR combined with Luminex technology for 46 ß-HPV genotypes. One hundred thirteen (61.1%) of 185 fingernail samples were positive for ß-HPV, and the median number of types detected in positive samples was 2 (interquartile range: 1-4). The most common genotypes detected were HPV-23 (ß-2) (13.5%), HPV-38 (ß-2) (13.0%), HPV-5 (ß-1) (9.2%), HPV-107 (ß-2) (8.7%), and HPV-120 (ß-2) (8.7%). In multivariate analysis, ß-HPV detection was associated with age (prevalence ratio [PR] for women 40-51 years versus 30-39 years = 1.30, 95% CI: 1.05-1.62) and race (PR for non-white versus white race = 0.65, 95% CI: 0.45-0.94). The prevalence of ß-HPV in fingernail samples from healthy mid-adult women was similar to the prevalence of ß-HPV reported at other cutaneous sites in prior studies. We did not identify any significant health or sexual behavior predictors of ß-HPV detection in fingernails. Our results support the hypothesis that fingers may serve as a source of transmission or autoinoculation of cutaneous HPVs to other anatomic sites.

Nuclear myosin 1 associates with papillomavirus E2 regulatory protein and influences viral replication.

Nuclear myosin 1c (NM1) associates with RNA polymerases and is a partner in the chromatin remodeling complex B-WICH. This complex, which also contains WSTF and SNF2h proteins, is involved in transcriptional regulation. We report herein that papillomavirus protein E2 binds to NM1 and co-precipitates with the WSTF and SNF2h proteins. Our data suggest that E2 associates with the cellular B-WICH complex through binding to NM1. E2 and NM1 associate via their N-terminal domains and this interaction is ATP dependent. The cellular multifunctional protein Brd4 and beta-actin are also present in the NM1-E2 complex. NM1 downregulation by siRNA increases the replication of the BPV1 and HPV5 genomes but does not affect HPV18 genome replication. These results suggest that the B-WICH complex may play a role in the papillomavirus life cycle through NM1 and E2 protein interaction.

Detection of novel Betapapillomaviruses and Gammapapillomaviruses in eyebrow hair follicles using a single-tube 'hanging droplet' PCR assay with modified pan-PV CODEHOP primers.

A modified pan-PV consensus-degenerate hybrid oligonucleotide primer (CODEHOP) PCR was developed for generic and sensitive detection of a broad-spectrum of human papillomaviruses (HPVs) infecting the cutaneous epithelium. To test the analytical sensitivity of the assay we examined 149 eyebrow hair follicle specimens from immunocompetent male patients. HPV DNA was detected in 60 % (89/149) of analysed eyebrow samples with a total of 48 different HPV sequences, representing 21 previously described HPVs and 27 putative novel HPV types. Evidence for ten novel HPV subtypes and seven viral variants, clustering to three out of five genera containing cutaneous HPVs, was also obtained. Thus, we have shown that the modified pan-PV CODEHOP PCR assay is able to identify multiple HPV types, even from different genera, in the same clinical sample. Overall, these results demonstrate that the pan-PV CODEHOP PCR is an excellent tool for screening and identification of novel cutaneous HPVs, even in samples with low viral loads.

Molecular Mechanisms of Human Papillomavirus Induced Skin Carcinogenesis.

Infection of the cutaneous skin with human papillomaviruses (HPV) of genus betapapillomavirus (ßHPV) is associated with the development of premalignant actinic keratoses and squamous cell carcinoma. Due to the higher viral loads of ßHPVs in actinic keratoses than in cancerous lesions, it is currently discussed that these viruses play a carcinogenic role in cancer initiation. In vitro assays performed to characterize the cell transforming activities of high-risk HPV types of genus alphapapillomavirus have markedly contributed to the present knowledge on their oncogenic functions. However, these assays failed to detect oncogenic functions of ßHPV early proteins. They were not suitable for investigations aiming to study the interactive role of ßHPV positive epidermis with mesenchymal cells and the extracellular matrix. This review focuses on ßHPV gene functions with special focus on oncogenic mechanisms that may be relevant for skin cancer development.

Concordance of Beta-papillomavirus across anogenital and oral anatomic sites of men: The HIM Study.

We evaluated the concordance between ß-HPVs detected in external genital skin, anal canal, and oral cavity specimens collected simultaneously from 717 men that were participating in the multinational HIM Study. Viral genotyping was performed using the Luminex technology. Species- and type-specific concordance was measured using kappa statistics for agreement. Overall, concordance of ß-HPVs across sites was low and mainly observed among paired genital/anal canal samples. When grouped by species, solely ß-4 HPVs showed moderate concordance in genital/anal pairs (κ = 0.457), which could be attributed to the substantial concordance of HPV-92 in men from Brazil and Mexico (κ > 0.610). ß-HPV type concordance was higher in Mexico, where HPV-19 was consistently concordant in all anatomic site combinations. Our analysis indicates that type-specific concordance across sites is limited to few viral types; however, these infections seem to occur more often than would be expected by chance, suggesting that although rare, there is agreement among sites.