Mucosal Human Papillomavirus Types Research Articles

Surface material analysis for human papillomavirus detection in nail Bowen's disease caused by HPV type 58.

Over the past few years, cases of human papillomavirus (HPV) infection in nail Bowen's disease have been reported. This disease presents diagnostic challenges due to its similarity to nail malignant melanoma, particularly with respect to the clinical manifestation of black nail streaks. While skin biopsy is usually employed for diagnosis, it is an invasive procedure. We report the case of a 52-year-old healthy Japanese male with a pigmented streak on the nail of the fourth finger of his right hand, which had extended from the central to the lateral nail fold within 4 months. Dermoscopic examination revealed a dark-brown pigmented band with splinter microhemorrhage. Clinically, nail Bowen's disease was suspected. The lesion was excised in strips under local anesthesia. Histopathological examination revealed hyperkeratosis, parakeratosis, papillomatosis, and dyskeratotic cells with atypical nuclei irregularly arranged. Immunohistochemistry using anti-HPV L1 antibody detected HPV-positive cells in the upper epidermis and stratum corneum of the nail matrix. Mucosal high-risk HPV type 58 DNA was detected from brush cytology of the keratotic surface prior to surgery, which was confirmed in formalin-fixed, paraffin-embedded excised samples using polymerase chain reaction (PCR) and subsequent direct DNA sequencing. Our case highlights HPV type 58 as a potential causative agent of nail Bowen's disease and shows that brush cytology of the surface material prior to excision may be a useful and less invasive way for mucosal high-risk HPV detection. PCR analysis of the nail surface could serve as a supplementary diagnostic tool for nail Bowen's disease.

Alteration of Na/H exchange regulatory factor-1 protein levels in anogenital lesions positive for mucosal high-risk human papillomavirus type 16

Mucosal high-risk (HR) human papillomaviruses (HPV) are associated with anogenital carcinogenesis. The products of two early genes, E6 and E7, act as major viral oncoproteins. Functional studies in experimental models showed that HPV16 E6 induces degradation of the PDZ protein, the Na+/H+ exchanger regulatory factor-1 (NHERF-1). Here, we determined NHERF-1 protein levels by immunohistochemistry (IHC) in (i) benign anogenital warts (n = 8) (ii) premalignant lesions (L-SIL and H-SIL) (n = 43) and (iii) invasive cervical squamous cell carcinomas (SCC) (n = 17). A decrease of NHERF-1 protein level was not observed in genital warts in comparison to healthy epithelium. Conversely, a clearly decrease in NHERF-1 protein levels was observed in HPV16-positive pre-malignant and malignant lesions, while the phenomenon was much attenuated in lesions induced by other HR HPV types. In conclusion, these findings show that mucosal HPV types differently impact on NHERF-1 protein level in benign and malignant anogenital lesions.

E6-E7 based nested multiplex PCR assay for genital HPV detection and simultaneous typing of 15 high and low-risk HPV types

PurposeDue to a wide range of Human Papillomavirus (HPV) types associated with genital cancers; HPV genotyping remains important for the introduction of an appropriate vaccine, disease diagnosis, follow-up and epidemiological surveys. Currently, available molecular genotyping assays are not only expensive but also requires dedicated and expensive equipment which is not feasible in the majority of low-and-middle-socioeconomic countries. The purpose of the study was to develop and evaluated a cost-effective nested-multiplex polymerase chain reaction (NM-PCR) assay for HPV genotyping. MethodsHPV-DNA containing plasmids and cervical scrapings from histologically confirmed cervical cancer cases were used to evaluate the NM-PCR. In the first round PCR, a set of consensus primers were used to amplify 38 mucosal HPV types. HPV Type-specific primers were used in the second-round polymerase chain reaction (PCR) to amplify 15 HPV types in three multiplex cocktails. The assay sensitivity was determined with the control panel containing one to 1010genome equivalents (GE). DNA sequencing was done to confirm the PCR results. ResultsThe assay was able to amplify all HPV types and detected as few as 50GE per reaction. A total of 23 endo-cervical samples obtained from healthy, HPV negative subjects and 52 histologically confirmed cervical scrapings were processed for HPV genotyping by NM-PCR. HPV DNA was detected in all histologically confirmed samples. DNA sequencing results showed complete concordance with PCR results. ConclusionsThe designed nested PCR based assay had good concordance with clinical histology and sequencing results and appears to be a promising tool for HPV genotyping especially in resource-constrained settings.

Cyclic AMP-Dependent Protein Kinase Exhibits Antagonistic Effects on the Replication Efficiency of Different Human Papillomavirus Types.

Several types of widespread human papillomaviruses (HPVs) may induce the transformation of infected cells, provoking the development of neoplasms. Two main genera of HPVs are classified as mucosatropic alphapapillomaviruses and cutaneotropic betapapillomaviruses (α- and β-HPVs, respectively), and they both include high-risk cancer-associated species. The absence of antiviral drugs has driven investigations into the details of the molecular mechanisms of the HPV life cycle. HPV replication depends on the viral helicase E1 and the transcription factor E2. Their biological activities are controlled by numerous cellular proteins, including protein kinases. Here, we report that ubiquitously expressed cyclic AMP-dependent protein kinase A (PKA) differentially regulates the replication of α-HPV11, α-HPV18, and β-HPV5. PKA stimulates the replication of both α-HPVs studied but has a more profound effect on the replication of high-risk α-HPV18. However, the replication of β-HPV5 is inhibited by activated PKA in human primary keratinocytes and U2OS cells. We show that the activation of PKA signaling by different pharmacological agents induces the rapid proteasomal degradation of the HPV5 E2 protein, which in turn leads to the downregulation of E2-dependent transcription. In contrast, PKA-stimulated induction of HPV18 replication is the result of the downregulation of the E8^E2 transcript encoding a potent viral transcriptional inhibitor together with the rapid upregulation of E1 and E2 protein levels. IMPORTANCE Several types of human papillomaviruses (HPVs) are causative agents of various types of epithelial cancers. Here, we report that ubiquitously expressed cyclic AMP-dependent protein kinase A (PKA) differentially regulates the replication of various types of HPVs during the initial amplification and maintenance phases of the viral life cycle. The replication of the skin cancer-related pathogen HPV5 is suppressed, whereas the replication of the cervical cancer-associated pathogen HPV18 is activated, in response to elevated PKA activity. To inhibit HPV5 replication, PKA targets the viral transcriptional activator E2, inducing its rapid proteasomal degradation. PKA-dependent stimulation of HPV18 replication relies on the downregulation of another E2 gene product, E8^E2, which encodes a potent transcriptional repressor. Our findings highlight, for the first time, protein kinase-related mechanistic differences in the regulation of the replication of mucosal and cutaneous HPV types.

Human Papillomavirus-type distribution in anogenital lesions of prepubertal children.

In contrast to adults, only limited data are available on the human papillomavirus (HPV)-type spectrum in anogenital warts (AGW) of children. This study aimed to evaluate the HPV-type spectrum in AGW of prepubertal children. In a retrospective German multicentre study, HPV genotyping was performed in AGW biopsies of 55 1- to 12-year-old children using HPV group-specific PCRs followed by hybridization with type-specific probes or sequence analysis. Human papillomavirus-DNA was found in 53 of the 55 AGW. In 58.5% (31/53) of the HPV-positive AGW, mucosal HPV types were detected. HPV6 (27/53, 50.9%) was the predominant type. 43.4% (23/53) of the lesions were induced by cutaneous HPV types (HPV2, HPV27, HPV57). Mucosal HPV types were significantly more common in children under 5years of age than in children 5years of age and older (22/25, 88.0% [95% CI: 70.0-95.8] vs. 9/28, 32.1% [95% CI: 17.9-50.7], P<0.001). In contrast, cutaneous HPV types were significantly more prevalent in the 5- to 12-year age group (4/25, 16.0% [95% CI 6.4-34.7] vs. 19/28, 67.9% [95% CI 49.3-82.1], P<0.001). Anogenital warts in 5- to 12-year-old children are frequently associated with cutaneous HPV types, possibly due to horizontal transmission. HPV typing, in addition to comprehensive clinical and psychosocial evaluation, can potentially help in the assessment of these cases.

Beta Human Papillomavirus and Merkel Cell Polyomavirus in Skin Neoplasms

Beta Human Papillomavirus and Merkel Cell Polyomavirus in Skin Neoplasms

Abstract IA15: Role of human papillomaviruses in carcinogenesis

Abstract Infectious agents represent a major group of risk factors for cancer development and contribute to about 15% of human cancers worldwide. Six viruses and one bacterium, i.e., human papillomavirus (HPV), hepatitis C virus (HCV), hepatitis B virus, human T-lymphotropic virus type I (HTLV-1), Epstein-Barr virus (EBV), Kaposi sarcoma-associated virus (KSHV), and Helicobacter pylori, have been clearly associated with human carcinogenesis. The mucosal high-risk (HR) HPV types are the etiologic factors of cervical cancers and subset of oropharyngeal cancers. In addition, ongoing studies concerning a subgroup of HPV types that infect the skin suggest their involvement, together with ultraviolet radiation (or solar exposure), in the development of nonmelanoma skin cancer (NMSC). Biologic studies have demonstrated that the products of two early genes from the HR HPV types, E6 and E7, play a key role in cancer development. Both viral oncoproteins are able to target several cellular pathways leading to the evasion of the immune surveillance and cellular transformation. These studies also substantially contributed to our understanding of key mechanisms involved in the normal life of the cell. In the last few years, we have performed additional studies on cutaneous and mucosal HPV types and have characterized novel oncogenic viral mechanisms involved in the evasion of the immune response and/or in cellular transformation. A few examples will be presented. Citation Format: Massimo Tommasino. Role of human papillomaviruses in carcinogenesis [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr IA15.

Mucosal and Cutaneous Human Papillomavirus Infections and Cancer Biology.

Papillomaviridae is a family of small non-enveloped icosahedral viruses with double-stranded circular DNA. More than 200 different human papillomaviruses (HPVs) have been listed so far. Based on epidemiological data, a subgroup of alphapapillomaviruses (alpha HPVs) was referred to as high-risk (HR) HPV types. HR HPVs are the etiological agents of anogenital cancer and a subset of head and neck cancers. The cutaneous HPV types, mainly from beta and gamma genera, are widely present on the surface of the skin in the general population. However, there is growing evidence of an etiological role of betapapillomaviruses (beta HPVs) in non-melanoma skin cancer (NMSC), together with ultraviolet (UV) radiation. Studies performed on mucosal HR HPV types, such as 16 and 18, showed that both oncoproteins E6 and E7 play a key role in cervical cancer by altering pathways involved in the host immune response to establish a persistent infection and by promoting cellular transformation. Continuous expression of E6 and E7 of mucosal HR HPV types is essential to initiate and to maintain the cellular transformation process, whereas expression of E6 and E7 of cutaneous HPV types is not required for the maintenance of the skin cancer phenotype. Beta HPV types appear to play a role in the initiation of skin carcinogenesis, by exacerbating the accumulation of UV radiation-induced DNA breaks and somatic mutations (the hit-and-run mechanism), and they would therefore act as facilitators rather than direct actors in NMSC. In this review, the natural history of HPV infection and the transforming properties of various HPV genera will be described, with a particular focus on describing the state of knowledge about the role of cutaneous HPV types in NMSC.

Human papillomavirus 16 and p16 positive nasal cutaneous squamous cell carcinoma in immunocompetent men in their twenties

Cutaneous squamous cell carcinoma is usually associated with long-term ultraviolet light exposure. Human papillomavirus 16 is a high-risk mucosal human papillomavirus type, usually associated with anogenital and oropharyngeal cancer. This paper describes the first two cases of human papillomavirus 16 and p16 related nasal cutaneous squamous cell carcinoma. Prospective case series from December 2015. Two young, male, fair-skinned patients had large (greater than 20 mm), rapidly growing, ulcerated lesions of the nasal tip. The tumours were excised, with at least a 6 mm margin, and the patients' noses were subsequently reconstructed. Neither patient had cervical lymphadenopathy or underwent adjuvant radiotherapy. Both patients were registered at the same general practice. The tumours were human papillomavirus 16 and p16 positive; the latter indicated that the virus was driving the disease process. Except for superficial burns, neither patient had other risk factors. Changes in sexual practices have led to an increase in human papillomavirus positive oropharyngeal carcinoma and there may be an associated increase in human papillomavirus type 16 positive nasal cutaneous squamous cell carcinoma.

G-101 Human papillomaviruses and carcinogenesis: well-established and novel models

Human papillomaviruses (HPVs) infect the cutaneous or mucosal epithelia. More than 200 HPV types have been isolated so far, and they are classified phylogenetically as genera and species. Persistent infections by the mucosal high-risk (HR) HPV types from genus alpha have been clearly associated with cancer development of the genital and upper respiratory tracts. The products of two early genes, E6 and E7, are the major HR HPV oncoproteins, being essential in all steps of the carcinogenic process. They exert their functions by interacting with a large number of cellular proteins, including the products of tumour suppressor genes, and altering their properties. Biological and epidemiological data indicate that beta HPV types, together with ultraviolet (UV) radiation, promote non-melanoma skin cancer development. However, in contrast to the HR mucosal HPV types, cutaneous beta HPV types appear to be required only at an early stage of carcinogenesis, facilitating the accumulation of UV-induced DNA mutations. Several findings also suggest that these HPV types and other carcinogens may synergize in the induction of malignancies at different anatomical sites.

Human papilloma virus: Apprehending the link with carcinogenesis and unveiling new research avenues (Review).

Human papilloma viruses (HPV) are a small group of non-enveloped viruses belonging to the Papillomaviridae family with strong similarities to polyoma viruses. The viral particles consist of a genome in the form of a circular double-stranded DNA, encompassing eight open reading frames, as well as a non-enveloped icosahedral capsid. HPV infection is considered the most common sexually transmitted disease in both sexes and is strongly implicated in the pathogenesis of different types of cancer. ‘High-risk’ mucosal HPV types, predominantly types 16, 18, 31, 33 and 35, are associated with most cervical, penile, vulvar, vaginal, anal, oropharyngeal cancers and pre-cancers. Screening for HPV is necessary for the prognosis and for determining treatment strategies for cancer. Novel HPV markers, including proteomic and genomic markers, as well as anti-papillomavirus vaccines are currently available. The aim of this comprehensive review was to thoroughly present the updated information on virus development, cancer occurrence, treatment and prevention strategies, in an attempt to shed further light into the field, including novel research avenues.

Mucosal and skin HPV types in tumour-free tonsils and tonsillar tumours.

Human papillomavirus (HPV) infection is associated with tonsillar cancer (TC) whose incidence in humans is increasing. Tonsillar tumours are not ordinarily preceded by clinically apparent precancerous lesions, and no markers of the early stage disease are available. Therefore, we evaluated the presence of an active HPV infection also in tumour-free tonsillar tissue. Formalin-fixed paraffin-embedded (FFPE) tonsillar specimens from 114 patients with TC and 114 age and gender matched controls were screened for the presence of HPV DNA, expression of HR-HPV E6 mRNA, and p16 overexpression. HPV DNA was identified in 3.5% of tumour-free tissues, HR-HPV16 and 58 and LR-HPV111 and 17 were each detected in a single sample. No HR HPV E6 mRNA and p16 overexpression was found. The prevalence of HPV DNA in TC was 69.3%, with HPV16 being the most common (94.9%). Eighty-four percent of HPV16-positive tumours expressed HR HPV E6 mRNA, while no E6 mRNA was present in samples positive for HPV52 and 58. The overexpression of p16 correlated well with HPV DNA in TC, but in tumour-free tonsils no overexpression of p16 was detected.Our data provide further evidence of the etiological role of HPV16 in TC. In tumour-free tissue, the presence of HR-HPVs was rare and silent, as shown by direct and indirect markers.

Alterations in the expression and activity of extracellular matrix components in HPV-associated infections and diseases

Infection with human papillomaviruses is associated with a series of benign and malignant hyperproliferative diseases that impose a heavy burden on human populations. A subgroup of mucosal human papillomavirus types are associated with the majority of cervical cancers and a relevant fraction of vulvar, vaginal, anal, penile and head and neck carcinomas. Human papillomaviruses mediate cell transformation by the expression of two pleiotropic oncoproteins that alter major cellular regulatory pathways. However, these viruses are not complete carcinogens, and further alterations within the infected cells and in their microenvironment are necessary for tumor establishment and progression. Alterations in components of the extracellular matrix for instance, matrix metalloproteinases and some of their regulators such as tissue inhibitors of metalloproteinases, have been consistently reported in human papillomaviruses-associated diseases. Matrix metalloproteinases function by remodeling the extracellular matrix and alterations in their expression levels and/or activity are associated with pathological processes and clinical variables including local tumor invasion, metastasis, tumor relapse and overall patient prognosis and survival. In this review we present a summarized discussion on the current data concerning the impact of human papillomavirus infection on the activity and expression of extracellular matrix components. We further comment on the possibility of targeting extracellular matrix molecules in experimental treatment protocols.

Minor Capsid Protein L2 Polytope Induces Broad Protection against Oncogenic and Mucosal Human Papillomaviruses.

The amino terminus of the human papillomavirus (HPV) minor capsid protein L2 contains a major cross-neutralization epitope which provides the basis for the development of a broadly protecting HPV vaccine. A wide range of protection against different HPV types would eliminate one of the major drawbacks of the commercial, L1-based prophylactic vaccines. Previously, we have reported that insertion of the L2 epitope into a scaffold composed of bacterial thioredoxin protein generates a potent antigen inducing comprehensive protection against different animal and human papillomaviruses. We also reported, however, that although protection is broad, some oncogenic HPV types escape the neutralizing antibody response, if L2 epitopes from single HPV types are used as immunogen. We were able to compensate for this by applying a mix of thioredoxin proteins carrying L2 epitopes from HPV16, -31, and -51. As the development of a cost-efficient HPV prophylactic vaccines is one of our objectives, this approach is not feasible as it requires the development of multiple good manufacturing production processes in combination with a complex vaccine formulation. Here, we report the development of a thermostable thioredoxin-based single-peptide vaccine carrying an L2 polytope of up to 11 different HPV types. The L2 polytope antigens have excellent abilities in respect to broadness of protection and robustness of induced immune responses. To further increase immunogenicity, we fused the thioredoxin L2 polytope antigen with a heptamerization domain. In the final vaccine design, we achieve protective responses against all 14 oncogenic HPV types that we have analyzed plus the low-risk HPVs 6 and 11 and a number of cutaneous HPVs.IMPORTANCE Infections by a large number of human papillomaviruses lead to malignant and nonmalignant disease. Current commercial vaccines based on virus-like particles (VLPs) effectively protect against some HPV types but fail to do so for most others. Further, only about a third of all countries have access to the VLP vaccines. The minor capsid protein L2 has been shown to contain so-called neutralization epitopes within its N terminus. We designed polytopes comprising the L2 epitope amino acids 20 to 38 of up to 11 different mucosal HPV types and inserted them into the scaffold of thioredoxin derived from a thermophile archaebacterium. The antigen induced neutralizing antibody responses in mice and guinea pigs against 26 mucosal and cutaneous HPV types. Further, addition of a heptamerization domain significantly increased the immunogenicity. The final vaccine design comprising a heptamerized L2 8-mer thioredoxin single-peptide antigen with excellent thermal stability might overcome some of the limitations of the current VLP vaccines.

Preliminary study of analyzing mucosal human papillomaviruses in cutaneous warts by restriction fragment mass polymorphism.

Cutaneous human papillomavirus (HPV) types 1, 2, 4, 7 and 57 are reportedly found in cutaneous warts. However, there are few reports that have investigated the prevalence of mucosal HPV types in cutaneous warts. The aim of this study is to investigate the prevalence of mucosal HPV types in patients with cutaneous warts and to determine any association between HPV types and patient characteristics. We analyzed 62 wart samples that were taken from patients who were diagnosed with cutaneous warts, and 30 normal skin samples were used as negative control. We recorded the following characteristics: sex, age, type of warts, duration of warts, number of warts and patient's immune status. A matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS)-based restriction fragment mass polymorphism (RFMP) assay was used for HPV genotyping. Of the total 62 wart samples, 50 samples (81.6%) were positive for HPV genotypes. All of the negative controls (30 samples) using normal skin showed negative reaction. Mucosal HPV types (49 samples, 84.4%) were highly detected, and high- or probable high-risk HPV types (39 samples, 67.2%) were more common than lower risk HPV types (10 samples, 17.2%). A statistically significant association was observed between sex, age, duration of warts and the risk of HPV types. To the best of our knowledge, this is the first study to use the RFMP assay to analyze cutaneous wart-associated mucosal HPV types. The high prevalence of high-risk and probable high-risk HPV in this study is of great significance.

Cutaneous HPV and alpha-mucosal 9-valent HPV sero-status associations

Seroepidemiology of human papillomaviruses (HPV) among men is poorly understood. We examined the association between seropositivity to cutaneous HPV and 9-valent HPV (9vHPV) types. Six hundred men were randomly selected from the HPV Infection in Men (HIM) Study. Archived serum specimens were tested for antibodies against 9vHPV types [low-risk (6/11) and high-risk (16/18/31/33/45/52/58)], and 14 cutaneous types, including β-types 5/8/12/14/17/22/23/24/38/47, α-type-27, γ-type-4, µ-type-1, and ν-type-41, using a GST L1-based multiplex serology assay. Risk factor data were collected through questionnaires. Logistic regression was used to evaluate associations between mucosal and cutaneous HPV types. Approximately 21% of men were positive for ≥ 1 cutaneous HPV type, and ≥ 1 nine-valent HPV vaccine type at the same time. Men who were seropositive for any-cutaneous HPV were nearly twice as likely to be seropositive for 9vHPV (adjusted odds ratio (AOR) = 1.97, 95% confidence interval (CI): 1.30–2.99), high-risk (AOR = 1.83; 95% CI: 1.04–3.20), low-risk (AOR = 1.92; 95% CI: 1.16–3.18), and four-valent, 4vHPV, (AOR = 2.01; 95% CI: 1.25–3.21). Type-specific cutaneous HPV seropositivity (types: 8/14/17/23/38/27/4/1) was also positively associated with seropositivity to 9vHPV, high-risk, and low-risk categories. These data indicate that exposure to cutaneous HPV and 9vHPV types is common. Future longitudinal studies are needed to assess the temporality of these associations.

E6/E7-P53-POU2F1-CTHRC1 axis promotes cervical cancer metastasis and activates Wnt/PCP pathway

Cervical cancer is an infectious cancer and the most common gynecologic cancer worldwide. E6/E7, the early genes of the high-risk mucosal human papillomavirus type, play key roles in the carcinogenic process of cervical cancer. However, little was known about its roles in modulating tumor microenvironment, particular extracellular matrix (ECM). In this study, we found that E6/E7 could regulate multiple ECM proteins, especially collagen triple helix repeat containing 1 (CTHRC1). CTHRC1 is highly expressed in cervical cancer tissue and serum and closely correlated with clinicopathological parameters. CTHRC1 promotes cervical cancer cell migration and invasion in vitro and metastasis in vivo. E6/E7 regulates the expression of CTHRC1 in cervical cancer by E6/E7-p53-POU2F1 (POU class 2 homeobox 1) axis. Futhermore, CTHRC1 activates Wnt/PCP signaling pathway. Take together, E6/E7-p53-POU2F1-CTHRC1 axis promotes cervical cancer cell invasion and metastasis and may act as a potential therapeutic target for interventions against cervical cancer invasion and metastasis.

The PTPN14 Tumor Suppressor Is a Degradation Target of Human Papillomavirus E7.

Activation of signaling pathways ensuring cell growth is essential for the proliferative competence of human papillomavirus (HPV)-infected cells. Tyrosine kinases and phosphatases are key regulators of cellular growth control pathways. A recently identified potential cellular target of HPV E7 is the cytoplasmic protein tyrosine phosphatase PTPN14, which is a potential tumor suppressor and is linked to the control of the Hippo and Wnt/beta-catenin signaling pathways. In this study, we show that the E7 proteins of both high-risk and low-risk mucosal HPV types can interact with PTPN14. This interaction is independent of retinoblastoma protein (pRb) and involves residues in the carboxy-terminal region of E7. We also show that high-risk E7 induces proteasome-mediated degradation of PTPN14 in cells derived from cervical tumors. This degradation appears to be independent of cullin-1 or cullin-2 but most likely involves the UBR4/p600 ubiquitin ligase. The degree to which E7 downregulates PTPN14 would suggest that this interaction is important for the viral life cycle and potentially also for the development of malignancy. In support of this we find that overexpression of PTPN14 decreases the ability of HPV-16 E7 to cooperate with activated EJ-ras in primary cell transformation assays.IMPORTANCE This study links HPV E7 to the deregulation of protein tyrosine phosphatase signaling pathways. PTPN14 is classified as a potential tumor suppressor protein, and here we show that it is very susceptible to HPV E7-induced proteasome-mediated degradation. Intriguingly, this appears to use a mechanism that is different from that employed by E7 to target pRb. Therefore, this study has important implications for our understanding of the molecular basis for E7 function and also sheds important light on the potential role of PTPN14 as a tumor suppressor.

Prevalence and Determinants of Oral Human Papillomavirus Infection in 500 Young Adults from Italy.

Although the prevalence of human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) is increasing in developed countries and becoming a relevant health issue, the natural history of oral HPV infection is still unclear. Estimating the infection’s prevalence in specific populations and identifying risk factors can widen our understanding of its natural history and help to delineate appropriate prevention strategies. This study sought to (i) determine oral HPV prevalence and genotype distribution in a large series of young Italian adults, (ii) validate an oral rinse sampling/storage protocol, and (iii) pinpoint factors associated with oral HPV infection. Five hundred students, nurses, and technicians (19–35 years-old) studying and working at/for the University of Padua were recruited. Each participant was provided with an oral rinse sampling kit and instructions for use. They were also asked to complete an anonymous questionnaire concerning their demographic characteristics and behaviors. The questionnaires and oral rinse containers were labeled with the same identification code number. The oral rinse samples were tested using a bead-based multiplex BSGP5+/6+-MPG genotyping assay which amplifies the L1 region of 51 mucosal HPV types. The prevalence of oral HPV infection was 4.0% (95% confidence interval (CI), 2.5%-6.1%); those of 14 high-risk HPV types and of HPV-type 16 (HPV16) infection were 2.2% (95% CI, 1.1%-3.9%) and 1.6% (95% CI, 0.6%-3.1%), respectively. HPV16 was the most frequent genotype (40.0% of oral HPV infections). No association was found between oral infection and the co-variables studied (gender, tobacco, alcohol and illegal drug use, number of sex and oral sex partners, HPV vaccination status, history of HPV and sexually transmitted infections, abnormal pap smears, recurrent tonsillitis and tonsillectomy). The oral rinse sampling protocol outlined here proved to be simple, efficient and well tolerated, and the prevalence rate can be considered reliable and thus useful to guide future research. Determinants of oral HPV infection are still unclear and further studies are certainly warranted.

Chimeric L2-Based Virus-Like Particle (VLP) Vaccines Targeting Cutaneous Human Papillomaviruses (HPV)

Common cutaneous human papillomavirus (HPV) types induce skin warts, whereas species beta HPV are implicated, together with UV-radiation, in the development of non-melanoma skin cancer (NMSC) in immunosuppressed patients. Licensed HPV vaccines contain virus-like particles (VLP) self-assembled from L1 major capsid proteins that provide type-restricted protection against mucosal HPV infections causing cervical and other ano-genital and oro-pharyngeal carcinomas and warts (condylomas), but do not target heterologous HPV. Experimental papillomavirus vaccines have been designed based on L2 minor capsid proteins that contain type-common neutralization epitopes, to broaden protection to heterologous mucosal and cutaneous HPV types. Repetitive display of the HPV16 L2 cross-neutralization epitope RG1 (amino acids (aa) 17–36) on the surface of HPV16 L1 VLP has greatly enhanced immunogenicity of the L2 peptide. To more directly target cutaneous HPV, L1 fusion proteins were designed that incorporate the RG1 homolog of beta HPV17, the beta HPV5 L2 peptide aa53-72, or the common cutaneous HPV4 RG1 homolog, inserted into DE surface loops of HPV1, 5, 16 or 18 L1 VLP scaffolds. Baculovirus expressed chimeric proteins self-assembled into VLP and VLP-raised NZW rabbit immune sera were evaluated by ELISA and L1- and L2-based pseudovirion (PsV) neutralizing assays, including 12 novel beta PsV types. Chimeric VLP displaying the HPV17 RG1 epitope, but not the HPV5L2 aa53-72 epitope, induced cross-neutralizing humoral immune responses to beta HPV. In vivo cross-protection was evaluated by passive serum transfer in a murine PsV challenge model. Immune sera to HPV16L1-17RG1 VLP (cross-) protected against beta HPV5/20/24/38/96/16 (but not type 76), while antisera to HPV5L1-17RG1 VLP cross-protected against HPV20/24/96 only, and sera to HPV1L1-4RG1 VLP cross-protected against HPV4 challenge. In conclusion, RG1-based VLP are promising next generation vaccine candidates to target cutaneous HPV infections.