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.

High Ambient Solar UV Correlates with Greater Beta HPV Seropositivity in New South Wales, Australia.

BACKGROUND: Human papillomavirus (HPV) infection is highly prevalent worldwide and may have a role, with sun exposure, in causing cutaneous squamous cell carcinoma. Little is known about the relationship of UV exposure and seroprevalence of cutaneous HPVs in the general population. METHODS: Using multiplex serology, we estimated the seroprevalence of 23 beta and 7 gamma HPVs and 7 other antigens (mu HPV1, HPV63, nu HPV41, alpha HPV16; polyomaviruses HPyV7 and MCV; p53) in a population-based sample of 1,161 Australian 45 and Up Study participants with valid data from blood specimens collected from 2010 to 2012. We calculated prevalence ratios (PR) for the association of each antigen with residential ambient solar UV and other UV-related variables. RESULTS: Seropositivity for at least one beta or gamma HPV was high at 88% (beta HPVs 74%, gamma HPVs 70%), and less in women than men [e.g., PR beta-2 HPV38 = 0.70; 95% confidence interval (CI), 0.56-0.87; any gamma = 0.90; 95% CI, 0.84-0.97]. A high ambient UV level in the 10 years before study enrollment was associated with elevated seroprevalence for genus beta (PRtertile3vs1 any beta = 1.17; 95% CI, 1.07-1.28), and beta-1 to beta-3 species, but not for gamma HPVs. Other UV-related measures had less or no evidence of an association. CONCLUSIONS: Seroprevalence of cutaneous beta HPVs is higher with higher ambient UV exposure in the past 10 years. IMPACT: The observed association between ambient UV in the past 10 years and cutaneous HPVs supports further study of the possible joint role of solar UV and HPV in causing skin cancer.

HPV and skin carcinogenesis.

Epidemiological and biological studies provide several lines of evidence for the involvement of cutaneous beta human papillomaviruses (HPVs), together with ultraviolet (UV) radiation, in the development of cutaneous squamous cell carcinoma. These viruses appear to act with a hit-and-run mechanism, being necessary at an early stage of carcinogenesis and being dispensable for the maintenance of the malignant phenotype. Studies in experimental models show that beta HPVs, mainly via the E6 and E7 oncoproteins, are able to promote proliferation and to circumvent cellular stresses induced by UV radiation. These findings support a model of skin carcinogenesis in which beta HPV-infected keratinocytes remain alive despite the accumulation of UV-induced DNA mutations. In this manner, these cells become highly susceptible to progression towards malignancy. Thus, UV radiation is the main driver of skin cancer development, while beta HPVs act as facilitators of the accumulation of UV-induced DNA mutations.

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.

Cervical Infection with Cutaneous Beta and Mucosal Alpha Papillomaviruses.

Background: Alpha-human papillomavirus (α-HPV) plays a causal role in cervical cancer, but little is known about the epidemiology of genital Beta-human papillomavirus (ß-HPV) infection.Methods: We used Luminex and PCR hybridization to detect ß- and α-HPVs prevalence at enrollment and 12-month follow-up in cervical samples from 505 women enrolled in the Ludwig-McGill cohort study. We compared epidemiologic correlates of both ß- and α-HPVs and compared genotypes between these genera with respect to co-occurrence and association with cervical cytologic abnormalities.Results: Infection with ß-HPV types was more prevalent than that with α-HPV types at both visits (cumulative prevalences: 27.3% vs. 21.6%, respectively, P = 0.034). ß-HPVs were mostly transient; however, only 1.98% women retained their original positivity at 12 months, whereas persistence was higher for α-HPVs (5.15%; P = 0.007). Age, parity, and sexual activity variables were predictors of α-HPV but not of ß-HPV. α- and ß-HPV types occurred independently. Increased risk of cervical abnormalities was restricted to women infected with α-9 or α-6 HPV types. We found no epidemiologic correlates for ß-HPV infections.Conclusions: Detection of ß-HPV types in the cervix tends to occur as random and transient episodes not explained via the sexual-transmission correlates that characterize infections by α-HPVs.Impact: Although it is plausible that ß-HPVs may play a direct or indirect carcinogenic role, the lack of epidemiologic correlates for detection episodes of these viruses and lack of association with cervical lesions speak against their ancillary role as sexually transmitted agents in cervical carcinogenesis. Cancer Epidemiol Biomarkers Prev; 26(8); 1312-20. ©2017 AACR.

[Human papilloma virus infection in basal cell carcinoma of the skin: a systematic review and meta-analysis study].

Human papillomaviruses (HPVs) are a large and ubiquitous group of viruses that some of them have been suggested as a co-factor in the development of non-melanoma skin cancers. The aim of this meta-analysis study was to evaluate HPVs' prevalence in basal cell carcinoma (BCC) of the skin and the risk of them in the BCC patients compared with the healthy controls. Five databases were searched from January 1980 to February 2017. A random-effects meta-analysis was done with the event rate (ER) for the prevalence of HPVs and odds ratio (OR) for estimation of the incidence of HPVs. Out of 1087 studies, 45 studies were included in the review. The pooled analysis demonstrated that the incidence of γ-HPV was effective in the BCC patients compared with the healthy controls [OR = 1.97; 95% CI: 1.52-2.55; p < 0.00001], but not for α-HPV, ß-HPV and epidermodysplasia verruciformis (EV)-HPV (p > 0.05). The pooled ER of incidence of ß1-HPV in the BCC patients was z3.3% and for ß2-HPV in BCC patients was 44.2%. In conclusion, this meta-analysis showed that probably the risk of γ-HPV was more on BCC patients and also the rate of γ-HPV was higher than α-, ß- and EV-HPVs in the BCC patients.

The biology of beta human papillomaviruses.

The beta genus comprises more than 50 beta human papillomavirus (HPV) types that are suspected to be involved, together with ultraviolet (UV) irradiation, in the development of non-melanoma skin cancer (NMSC), the most common form of human cancer. Two members of the genus beta, HPV5 and HPV8, were first identified in patients with a genetic disorder, epidermodysplasia verruciformis (EV), that confers high susceptibility to beta HPV infection and NMSC development. The fact that organ transplant recipients (OTRs) with an impaired immune system have an elevated risk of NMSC raised the hypothesis that beta HPV types may also be involved in skin carcinogenesis in non-EV patients. Epidemiological studies have shown that serological and viral DNA markers are weakly, but significantly, associated with history of NMSC in OTRs and the general population. Functional studies on mucosal high-risk (HR) HPV types have clearly demonstrated that the products of two early genes, E6 and E7, are the main viral oncoproteins, which are able to deregulate events closely linked to transformation, such as cell cycle progression and apoptosis. Studies on a small number of beta HPV types have shown that their E6 and E7 oncoproteins also have the ability to interfere with the regulation of key pathways/events associated with cellular transformation. However, the initial functional data indicate that the molecular mechanisms leading to cellular transformation are different from those of mucosal HR HPV types. Beta HPV types may act only at early stages of carcinogenesis, by potentiating the deleterious effects of other carcinogens, such as UV radiation.

Beta genus papillomaviruses and skin cancer.

A role for the beta genus HPVs in keratinocyte carcinoma (KC) remains to be established. In this article we examine the potential role of the beta HPVs in cancer revealed by the epidemiology associating these viruses with KC and supported by oncogenic properties of the beta HPV proteins. Unlike the cancer associated alpha genus HPVs, in which transcriptionally active viral genomes are invariably found associated with the cancers, that is not the case for the beta genus HPVs and keratinocyte carcinomas. Thus a role for the beta HPVs in KC would necessarily be in the carcinogenesis initiation and not in the maintenance of the tumor.

Nuclear export of cutaneous HPV8 E7 oncoprotein is mediated by a leucine-rich nuclear export signal via a CRM1 pathway.

We recently determined that the nuclear import of cutaneous beta genus HPV8 E7 oncoprotein it is mediated by its zinc-binding domain via direct hydrophobic interactions with the FG nucleoporins Nup62 and Nup153 (Onder and Moroianu, 2014). Here we investigated the nuclear export of HPV8 E7 oncoprotein using confocal microscopy after transfections of HeLa cells with EGFP-8cE7 and mutant plasmids and treatment with Ratjadone A nuclear export inhibitor. We determined that HPV8 E7 contains a leucine-rich nuclear export signal (NES), 76IRTFQELLF84, within its zinc-binding domain that mediates its nuclear export via a CRM1 pathway. We found that HPV8 E7 interacts with CRM1 and that the hydrophobic amino acid residues I76, F79 and L82 of the NES are essential for this interaction and for nuclear export of HPV8 E7 oncoprotein.

Human Beta-papillomavirus infection and keratinocyte carcinomas.

Although the role of oncogenic human Alpha-papillomaviruses (HPVs) in the development of mucosal carcinomas at different body sites (eg cervix, anus, oropharynx) is fully recognized, a role for HPV in keratinocyte carcinomas (KCs; basal and squamous cell carcinomas) of the skin is not yet clear. KCs are the most common cancers in Caucasians, with the major risk factor being ultraviolet (UV) light exposure. A possible role for Beta-HPV types (BetaPV) in the development of KC was suggested several decades ago, supported by a number of epidemiological studies. Our current review summarizes the recent molecular and histopathological evidence in support of a causal association between BetaPV and the development of KC, and outlines the suspected synergistic effect of viral gene expression with UV radiation and immune suppression. Further insights into the molecular pathways and protein interactions used by BetaPV and the host cell is likely to extend our understanding of the role of BetaPV in KC.

Human papillomaviruses and skin cancer.

Human papillomaviruses (HPVs) infect squamous epithelia and can induce hyperproliferative lesions. More than 120 different HPV types have been characterized and classified into five different genera. While mucosal high-risk HPVs have a well-established causal role in anogenital carcinogenesis, the biology of cutaneous HPVs is less well understood. The clinical relevance of genus beta-PV infection has clearly been demonstrated in patients suffering from epidermodysplasia verruciformis (EV), a rare inherited disease associated with ahigh rate of skin cancer. In the normal population genus beta-PV are suspected to have an etiologic role in skin carcinogenesis as well but this is still controversially discussed. Their oncogenic potency has been investigated in mouse models and in vitro. In 2009, the International Agency for Research on Cancer (IARC) classified the genus beta HPV types 5 and 8 as "possible carcinogenic" biological agents (group 2B) in EV disease. This chapter will give an overview on the knowns and unknowns of infections with genus beta-PV and discuss their potential impact on skin carcinogenesis in the general population.

HLA-C -35kb expression SNP is associated with differential control of ß-HPV infection in squamous cell carcinoma cases and controls.

A single nucleotide polymorphism (SNP) 35 kb upstream of the HLA-C gene is associated with HLA-C expression, and the high expressing genotype (CC) has been associated with HIV-I control. HLA-C is unique among the classical MHC class I molecules for its role in the control of viral infections and recognition of abnormal or missing self. This immunosurveillance is central to the pathogenesis of non-melanoma skin cancer (NMSC), and of squamous cell carcinoma (SCC) in particular. While sun exposure is a major risk factor for these cancers, cutaneous infections with genus ß-HPV have been implicated in the development of SCC. We hypothesized that the high expression HLA-C genotype is associated with ß-HPV infections. Therefore, we investigated the association between ß-HPV serology and the -35 kb SNP (rs9264942) in a population-based case-control study of 510 SCC cases and 608 controls. Among controls, the high expression -35 kb SNP genotype (CC) reduced the likelihood of positive serology for multiple (≥2) ß-HPV infections (OR = 0.49, 95% CI: 0.25-0.97), and ß-HPV species 2 infection (OR = 0.43, 95% CI: 0.23-0.79). However, no association with ß-HPV status was observed among SCC cases. Our findings suggest that underlying immunogenotype plays an important role in differential control of ß-HPV in SCC cases and controls.

Impact of inhibitors and L2 antibodies upon the infectivity of diverse alpha and beta human papillomavirus types.

The licensed human papillomavirus (HPV) vaccines elicit type-restricted immunity but do not target cutaneous HPV types of the beta genus that are associated with non-melanoma skin cancer in immune-compromised patients, and it is unclear if these diverse types share a common mechanism of infection. Residues 11-88 of minor capsid protein L2 contain cross-protective epitopes, and vaccination with concatamers of this region derived from as many as eight alpha HPV (L2 α11-88x8) is being developed as an alternative prophylactic vaccine with potentially broader efficacy. There is also interest in developing broadly protective topical microbicides, such as carrageenan or heparin that block HPV receptor interactions, or small molecule inhibitors of infection. Here we have examined several inhibitors of HPV infection and antisera to L2 α11-88x8 for their breadth of activity against infection by 34 HPV types from within both the alpha and beta families using pseudovirions (PsV) carrying a luciferase reporter as surrogates for native virus. We observed that both heparin and carrageenan prevented infection by mucosatropic HPV types, but surprisingly PsV of several epidermotropic alpha4 and beta HPV types exhibited increased infectivity especially at low inhibitor concentrations. Furin and γ-secretase inhibitors and L2 α11-88x8 antiserum blocked infection by all HPV PsV types tested. These findings suggest that the distinct tropism of mucosal and cutaneous HPV may reflect distinct cell surface receptor interactions, but a common uptake mechanism dependent upon furin and γ-secretase proteolytic activities. Carrageenan, which is being tested as a vaginal microbicide, broadly inhibited infection by the high-risk mucosatropic HPV PsV, but not most skin tropic alpha and beta HPV. Vaccination with an L2 multimer derived exclusively from alpha papillomavirus sequences induced antibodies that broadly neutralized PsV of all 34 HPVs from within both the alpha and beta families, suggesting each displays conserved L2 neutralizing epitopes.

[Natural history of the infection for human papillomavirus: an actualization]. / Historia natural de la infección por el virus del papiloma humano: una actualización.

In recent years, there have been major advances in our understanding of the biology and natural history of Human Papilloma Virus (HPV). Most papillomavirus infections are transmitted by close contact of either skin to skin or mucosa to mucosa. Sexual intercourse is not a requirement for genital HPV infection. Digital-oral infections occur and there is evidence that digital-genital and oral-genital contacts can result in the transmission of HPV, although in a relatively low percentage. Vertical transmission from mother to fetus is a common route of infection; in fact, it is recognized that more than 80% of infants born from mothers infected with genital HPV will be positive for HPV DNA determination in the nasal-pharyngeal region and oral mucosa. Women with transient infections often develop cytological abnormalities that take place while there is active HPV replication. This occurs because productive HPV infections result in cytological abnormalities in infected epithelial cells. The strong association between the risk of HPV infection and increased immune suppression, supports a direct biological effect of Human Immunodeficiency Virus (HIV) infection on the natural history of HPV.

Historia natural de la infección por el virus del papiloma humano: una actualización / Natural history of the infection for human papillomavirus: an actualization

Durante los últimos años, se han sucedido grandes avances en nuestro entendimiento acerca de la biología e historia natural del Virus del Papiloma Humano (VPH). La mayoría de las infecciones por papiloma virus son transmitidas por un contacto cercano bien sea de piel a piel o mucosa a mucosa. La relación sexual con penetración no es un requerimiento para la transmisión del VPH. Las infecciones orales y digitales por VPH ocurren, y existe evidencia de que el contacto digital-genital y genital-oral puede resultar en la transmisión del VPH, aunque en un porcentaje relativamente bajo. La transmisión vertical de la madre al feto es una vía frecuente de infección, de hecho, se reconoce que más del 80% de los neonatos nacido de madres infectadas con VPH genital serán positivos a la determinación del ADN del VPH en la región naso-faríngea y mucosa oral. Mujeres con infecciones transitorias frecuentemente desarrollan anormalidades citológicas mientras ocurra una replicación activa del VPH. Esto ocurre debido a que las infecciones productivas de VPH resultan en anormalidades citológicas en las células epiteliales infectadas. La fuerte asociación entre el riesgo de infección por VPH y el incremento en la supresión inmune apoya un efecto biológico directo de la infección por VIH en la historia natural del VPH.

In recent years, there have been major advances in our understanding of the biology and natural history of Human Papilloma Virus (HPV). Most papillomavirus infections are transmitted by close contact of either skin to skin or mucosa to mucosa. Sexual intercourse is not a requirement for genital HPV infection. Digital-oral infections occur and there is evidence that digital-genital and oral-genital contacts can result in the transmission of HPV, although in a relatively low percentage. Vertical transmission from mother to fetus is a common route of infection; in fact, it is recognized that more than 80% of infants born from mothers infected with genital HPV will be positive for HPV DNA determination in the nasal-pharyngeal region and oral mucosa. Women with transient infections often develop cytological abnormalities that take place while there is active HPV replication. This occurs because productive HPV infections result in cytological abnormalities in infected epithelial cells. The strong association between the risk of HPV infection and increased immune suppression, supports a direct biological effect of Human Immunodeficiency Virus (HIV) infection on the natural history of HPV.

Papillomavirus-associated squamous skin cancers following transplant immunosuppression: one Notch closer to control.

The frequent occurrence of cutaneous squamous cell carcinomas (SCCs) containing weakly tumorigenic human papillomaviruses (HPVs) following iatrogenic immunosuppression for organ transplantation remains incompletely understood. Here we address this problem in the light of recent insights into (1) the association of low-risk ß-HPVs with skin SCCs in the rare genetic syndromes of epidermodysplasia verruciformis and xeroderma pigmentosum, (2) the frequent recovery of post-transplant tumor control on substituting calcineurin-inhibitory with mTOR-inhibitory immunosuppression, (3) the unexpectedly favorable prognosis of node-positive SCCs containing high-risk α-HPVs originating in the activated immune niche of the oropharynx, (4) the rapid occurrence of HPV-negative SCCs in ultraviolet (UV)-damaged skin of melanoma patients receiving Raf-inhibitory drugs, and (5) the selective ability of ß-HPV E6 oncoproteins to inhibit Notch tumor-suppressive signaling in cutaneous and mesenchymal tissues. The crosstalk so implied between oncogenic UV-induced mutations, defective host immunity, and ß-HPV-dependent stromal-epithelial signaling suggests that immunosuppressants such as calcineurin inhibitors intensify mitogenic signalling in TP53-mutant keratinocytes while also abrogating immune-dependent Notch-mediated tumor repression. This emerging interplay between solar damage, viral homeostasis and immune control makes it timely to reappraise strategies for managing skin SCCs in transplant patients.

Expression of betapapillomavirus oncogenes increases the number of keratinocytes with stem cell-like properties.

Human papillomaviruses (HPV) of genus Betapapillomavirus (betaPV) are associated with nonmelanoma skin cancer development in epidermodysplasia verruciformis (EV) and immunosuppressed patients. Epidemiological and molecular studies suggest a carcinogenic activity of betaPV during early stages of cancer development. Since viral oncoproteins delay and perturb keratinocyte differentiation, they may have the capacity to either retain or confer a "stem cell-like" state on oncogene-expressing cells. The aim of this study was to determine (i) whether betaPV alters the expression of cell surface markers, such as CD44 and epithelial cell adhesion molecule (EpCAM), that have been associated with epithelial stemness, and (ii) whether this confers functional stem cell-like properties to human cutaneous keratinocytes. Fluorescence-activated cell sorter (FACS) analysis revealed an increase in the number of cells with high CD44 and EpCAM expression in keratinocyte cultures expressing HPV type 8 (HPV8) oncogenes E2, E6, and E7. Particularly through E7 expression, a distinct increase in clonogenicity and in the formation and size of tumor spheres was observed, accompanied by reduction of the epithelial differentiation marker Calgranulin B. These stem cell-like properties could be attributed to the pool of CD44(high) EpCAM(high) cells, which was increased within the E7 cultures of HPV5, -8, and -20. Enhanced EpCAM levels were present in organotypic skin cultures of primary keratinocytes expressing E7 of the oncogenic HPV types HPV5, -8, and -16 and in clinical samples from EV patients. In conclusion, our data show that betaPV may increase the number of stem cell-like cells present during early carcinogenesis and thus enable the persistence and accumulation of DNA damage necessary to generate malignant stem cells.