German evidence and consensus-based (S3) guideline: Vaccination recommendations for the prevention of HPV-associated lesions.

Anogenital and oropharyngeal infections with human papilloma viruses (HPV) are common. Clinically manifest disease may significantly impact quality of life; the treatment of HPV-associated lesions is associated with a high rate of recurrence and invasive neoplasms, such as cervical, anal, vulvar, penile, and oropharyngeal cancers, which are characterized by significant morbidity and mortality. Vaccination against HPV is an effective and safe measure for the primary prevention of HPV-associated lesions, but immunization rates are still low in Germany. The present publication is an abridged version of the German evidence and consensus-based guideline "Vaccination recommendations for the prevention of HPV-associated lesions", which is available on the website of the German Association of the Scientific Medical Societies (AWMF). On the basis of a systematic review with meta-analyses, a representative panel developed and agreed upon recommendations for the vaccination of different populations against HPV. In addition, consensus-based recommendations were developed for specific issues relevant to everyday practice. Based on current evidence and a representative expert consensus, these recommendations are intended to provide guidance in a field in which there is often uncertainty and in which both patients and health care providers are sometimes confronted with controversial and emotionally charged points of view.

Human papillomavirus and posttransplantation cutaneous squamous cell carcinoma: A multicenter, prospective cohort study.

Organ transplant recipients (OTRs) have a 100-fold increased risk of cutaneous squamous cell carcinoma (cSCC). We prospectively evaluated the association between ß genus human papillomaviruses (ßPV) and keratinocyte carcinoma in OTRs. Two OTR cohorts without cSCC were assembled: cohort 1 was transplanted in 2003-2006 (n = 274) and cohort 2 was transplanted in 1986-2002 (n = 352). Participants were followed until death or cessation of follow-up in 2016. ßPV infection was assessed in eyebrow hair by using polymerase chain reaction-based methods. ßPV IgG seroresponses were determined with multiplex serology. A competing risk model with delayed entry was used to estimate cumulative incidence of histologically proven cSCC and the effect of ßPV by using a multivariable Cox regression model. Results are reported as adjusted hazard ratios (HRs). OTRs with 5 or more different ßPV types in eyebrow hair had 1.7 times the risk of cSCC vs OTRs with 0 to 4 different types (HR 1.7, 95% confidence interval 1.1-2.6). A similar risk was seen with high ßPV loads (HR 1.8, 95% confidence interval 1.2-2.8). No significant associations were seen between serum antibodies and cSCC or between ßPV and basal cell carcinoma. The diversity and load of ßPV types in eyebrow hair are associated with cSCC risk in OTRs, providing evidence that ßPV is associated with cSCC carcinogenesis and may present a target for future preventive strategies.

Macrophage migration inhibitory factor protects from nonmelanoma epidermal tumors by regulating the number of antigen-presenting cells in skin.

The response of the skin to harmful environmental agents is shaped decisively by the status of the immune system. Keratinocytes constitutively express and secrete the chemokine-like mediator, macrophage migration inhibitory factor (MIF), more strongly than dermal fibroblasts, thereby creating a MIF gradient in skin. By using global and epidermis-restricted Mif-knockout (Mif-/- and K14-Cre+/tg; Miffl/fl) mice, we found that MIF both recruits and maintains antigen-presenting cells in the dermis/epidermis. The reduced presence of antigen-presenting cells in the absence of MIF was associated with accelerated and increased formation of nonmelanoma skin tumors during chemical carcinogenesis. Our results demonstrate that MIF is essential for maintaining innate immunity in skin. Loss of keratinocyte-derived MIF leads to a loss of control of epithelial skin tumor formation in chemical skin carcinogenesis, which highlights an unexpected tumor-suppressive activity of MIF in murine skin.-Brocks, T., Fedorchenko, O., Schliermann, N., Stein, A., Moll, U. M., Seegobin, S., Dewor, M., Hallek, M., Marquardt, Y., Fietkau, K., Heise, R., Huth, S., Pfister, H., Bernhagen, J., Bucala, R., Baron, J. M., Fingerle-Rowson, G. Macrophage migration inhibitory factor protects from nonmelanoma epidermal tumors by regulating the number of antigen-presenting cells in skin.

Dynamics of BKPyV reactivation and risk of hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation.

OBJECTIVES: Aim of this retrospective study was to analyze the dynamics of BKPyV reactivation in allogeneic hematopoietic stem cell transplant recipients in order to identify patients with higher risk to develop BKPyV-associated hemorrhagic cystitis (BKPyV-associated HC). METHODS: The study included 58 allo-HSCT recipients from the University Hospital of Cologne detected BKPyV positive by real-time PCR between 2009 and 2015. For correlative analysis, the first detected BKPyV-DNA load in urine and in plasma as well as the onset and severity of HC following the first day of conditioning regimen was considered. Phylogenetic analysis of BKPyV isolates was performed. RESULTS: In 25 of 58 patients, BKPyV-DNA was detected in urine only (group U), whereas 33 patients developed additional viremia (group P). A chronologic sequence viruria-viremia-HC was identified. Viral load of >106 copies/mL at first viruria and evidence of viremia after 45 days from the start of conditioning represented risk factors for the onset of HC. Molecular characterization revealed a non-stereotypic distribution of viral subtypes across groups U and P. CONCLUSIONS: Monitoring of BKPyV-DNA by real-time PCR after initiation of conditioning, regularly performed in clinical practice, can be a crucial tool for the early identification of patients with higher risk of BKPyV-associated HC.

Anal chromoendoscopy using gastroenterological video-endoscopes: A new method to perform high resolution anoscopy for diagnosing intraepithelial neoplasia and anal carcinoma in HIV-infected patients.

Introduction Anal carcinoma represents an increasing problem in HIV-infected patients. Anal intraepithelial neoplasia (AIN), the precursor lesion, is currently diagnosed by high-resolution anoscopy (HRA) using optical magnification derived from gynecological colposcopy. This prospective study evaluates anal chromoendoscopy (ACE) using standard gastroenterological video-endoscopes in diagnosing AIN. Methods After clinical examination, proctoscopy and surface staining with acetic acid followed by Lugol's solution, ACE was performed with a mucosectomy cap on the tip of the endoscope. Biopsy specimens were collected from areas with a pathological staining pattern and from areas with normal appearance; combined results were considered as reference. Results Two hundred eleven HIV-positive patients seen between 2007 and 2013 were evaluated. Of these, 95.7 % were males, and the median age was 45 years. In 86.7 %, the mode of HIV transmission was sex among males. Combination antiretroviral treatment was applied in 75.8 %. The sensitivity of ACE in diagnosing AIN was 0.85, the specificity was 0.55, the positive predictive value was 0.50, and the negative predictive value (NPV) was 0.87. Diagnostic performance increased in individuals with high-grade lesions (NPV: 0.99) and in the second study period from 2011 to 2013. Side effects were rare and of minor clinical relevance. Conclusions Anal chromoendoscopy is safe and effective in diagnosing AIN in a population of HIV-infected patients. It is particularly useful for the exclusion of high-grade lesions that have the strongest risk of progression to anal carcinoma. Therefore, ACE may become a valuable new tool to manage AIN and to prevent anal malignancy in HIV-positive patients.

The levels of epithelial anchor proteins ß-catenin and zona occludens-1 are altered by E7 of human papillomaviruses 5 and 8.

Infection with viruses of the genus Betapapillomavirus, ß-human papillomaviruses (ß-HPV), is implicated in the development of non-melanoma skin cancer. This was first evidenced for HPV5 and HPV8 in patients with the skin disease epidermodysplasia verruciformis (EV). The relocalization of the junctional bridging proteins ß-catenin and zona occludens-1 (ZO-1) from the adherens and tight junctions are common processes of the epithelial-mesenchymal transition (EMT) associated with tumour invasion. Here, we report that ß-catenin and ZO-1 are strongly upregulated by the E7 oncoproteins of HPV5 and HPV8 in keratinocytes grown in organotypic skin cultures. Although the membrane-tethered form of ß-catenin was elevated, no signs of ß-catenin activity within the canonical Wnt signalling pathway could be detected. The upregulation of ß-catenin and ZO-1 could also be confirmed in the skin of HPV8 transgenic mice as well as in cutaneous squamous cell carcinomas of EV patients. These data provide the first evidence that ß-catenin and ZO-1 are direct targets of E7 of the oncogenic ß-HPV types 5 and 8. The ability to deregulate these epithelial junction proteins may contribute to the oncogenic potential of these viruses in human skin.

High prevalence of human papillomaviruses in Ghanaian pregnant women.

Data about the prevalence of human papillomaviruses (HPV) in African women with normal and abnormal cervical cytology are still scarce. Current HPV vaccines contain HPV types, which mainly represent the HPV epidemiology of industrial countries. As further developments of HPV vaccines are going on, it is necessary to regard regional differences in HPV type prevalence to ensure optimal protection by the vaccine. Vaginal swabs of Ghanaian pregnant women, routinely collected before delivery to rule out bacterial infections causing early onset sepsis, were screened for 12 high-risk (HR), 13 probably/possibly (pHR), and 18 low-risk (LR) HPV types. Most pregnant women come for delivery to the hospital. This was considered as appropriate possibility to have an unselected group of women. HPV DNA were detected in 55/165 women (33.3, 95 % CI 26.3-41.1 %). Thirty-four out of fifty-five (61.8, 95 % CI 47.7-74.3 %) of HPV-positive women were infected with HR and/or pHR HPV types. The five most prevalent HR or pHR HPV types were HPV-52 and HPV-67 (7 women each, 4.2, 95 % CI 1.9-8.9 %), HPV-53 (six women, 3.6, 95 % CI 1.5-8.1 %), HPV-45 (five women, 3.0, 95 % CI 1.1-7.3 %), and HPV-18 (four women, 2.4, 95 % CI 0.8-6.5 %), respectively. HPV-16 was found in two women only (1.2, 95 % CI 0.2-4.8 %). Future HPV vaccine research may devote special interest to HPV-67 and HPV-53 provided further studies confirm their high prevalence in the general population of Sub-Saharan African countries. The true carcinogenic potential of HPV-67, which is a member of species alpha9 including HPV-16, and so far categorized as pHR, should be clarified.

Human papillomavirus mediated inhibition of DNA damage sensing and repair drives skin carcinogenesis.

BACKGROUND: The failure to mount an effective DNA damage response to repair UV induced cyclobutane pyrimidine dimers (CPDs) results in an increased propensity to develop cutaneous squamous cell carcinoma (cSCC). High-risk patient groups, such as organ transplant recipients (OTRs) frequently exhibit field cancerization at UV exposed body sites from which multiple human papillomavirus (HPV)-associated cSCCs develop rapidly, leading to profound morbidity and increased mortality. In vitro molecular evidence indicates that HPV of genus beta-papillomavirus (ß-PV) play an important role in accelerating the early stages of skin tumorigenesis. METHODS: We investigated the effects of UV induced DNA damage in murine models of ß-PV E6 oncoprotein driven skin tumorigenesis by crossing K14-HPV8-E6wt mice (developing skin tumors after UV treatment) with K14-CPD-photolyase animals and by generating the K14-HPV8-E6-K136N mutant mouse strain. Thymine dimers (marker for CPDs) and γH2AX (a marker for DNA double strand breaks) levels were determined in the murine skin and organotypic skin cultures of E6 expressing primary human keratinocytes after UV-irradiation by immunohistochemistry and in cell lines by In Cell Western blotting. Phosphorylation of ATR/Chk1 and ATM were assessed in cell lines and organotypic skin cultures by Western blots and immunohistochemistry. RESULTS: Skin tumor development after UV-irradiation in K14-HPV8-E6wt mice could completely be blocked through expression of CPD-photolyase. Through quantification of thymine dimers after UV irradiation in cells expressing E6 proteins with point mutations at conserved residues we identified a critical lysine in the C-terminal part of the protein for prevention of DNA damage repair and p300 binding. Whereas all K14-HPV8-E6wt animals develop skin tumors after UV expression of the HPV8-E6-K136N mutant significantly blocked skin tumor development after UV treatment. The persistence of CPDs in hyperproliferative epidermis K14-HPV8-E6wt skin resulted in the accumulation of γH2AX foci. DNA damage sensing was impaired in E6 positive cells grown as monolayer culture and in organotypic cultures, due to lack of phosphorylation of ATM, ATR and Chk1. CONCLUSION: We showed that cells expressing E6 fail to sense and mount an effective response to repair UV-induced DNA lesions and demonstrated a physiological relevance of E6-mediated inhibition of DNA damage repair for tumor initiation. These are the first mechanistical in vivo data on the tumorigenicity of HPV8 and demonstrate that the impairment of DNA damage repair pathways by the viral E6 protein is a critical factor in HPV-driven skin carcinogenesis.

Smoking and anal high-risk human papillomavirus DNA loads in HIV-positive men who have sex with men.

HIV-positive men who have sex with men (MSM) have an increased risk for anal human papillomavirus (HPV) infection, anal high-grade intraepithelial lesions (HSIL), and anal cancer. Smoking is associated with abnormal anal cytology and with an increased risk for anal cancer. We collected 3736 intraanal swabs from 803 HIV-positive MSM who participated in an anal cancer screening program between October 2003 and August 2014. HPV prevalence, anal cytology and HPV DNA load of high-risk (HR) HPV-types 16, 18, 31 and 33 of non-smokers and smokers were compared. HPV-typing was performed by alpha-HPV genus-specific PCR and hybridization with 38 type-specific probes using a multiplex genotyping assay. In samples positive for HPV16, 18, 31, or 33, HPV DNA loads were determined by type-specific real-time PCRs and expressed as HPV DNA copies per betaglobin gene copy. At baseline, HR-HPV DNA (80.5 vs. 89.0%, p=0.001), HPV16 DNA (41.6 vs. 52.3%, p=0.003), HPV18 DNA (15.5 vs. 26.0%, p<0.001), anal dysplasia (LSIL+HSIL; 51.5 vs. 58.4%, p=0.045) and HSIL (17.2 vs. 22.7%, p=0.048) were detected more frequently in smokers compared to non-smokers. Throughout the study period 32.7% of non-smokers and 39.9% of smokers developed HSIL (p=0.011), and three smokers developed anal cancer. Considering swabs from the entire study period (median HPV load value per patient per cytology grade), smokers with normal anal cytology had significantly higher HPV16 loads (median 0.29 vs. 0.87, n=201, p=0.007) and cumulative high-risk-HPV loads (median 0.53 vs. 1.08, n=297, p=0.004) than non-smokers. Since elevated HR-HPV DNA loads are associated with an increased risk for HPV-induced anogenital cancers, HPV-infected HIV-positive MSM should be counseled to refrain from smoking. Additionally, for smokers, shorter anal cancer screening intervals than for non-smokers may be appropriate.

Activation-induced cytidine deaminase is dispensable for virus-mediated liver and skin tumor development in mouse models.

Activation-induced cytidine deaminase (AID) not only promotes immune diversity by initiating somatic hypermutation and class switch recombination in immunoglobulin genes but also provokes genomic instability by introducing translocations and mutations into non-immunoglobulin genes. To test whether AID is essential for virus-induced tumor development, we used two transgenic tumor models: mice expressing hepatitis C virus (HCV) core proteins (HCV-Tg), driven by the hepatitis B virus promoter, and mice expressing human papillomavirus type 8 proteins (HPV8-Tg), driven by the Keratin 14 promoter. Both strains were analyzed in the absence and presence of AID by crossing each with AID (-/-) mice. There was no difference in the liver tumor frequency between the HCV-Tg/AID (+/+) and HCV-Tg/AID (-/-) mice at 20 months of age although the AID (+/+) mice showed more severe histological findings and increased cytokine expression. Furthermore, a low level of AID transcript was detected in the HCV-Tg/AID (+/+) liver tissue that was not derived from hepatocytes themselves but from intra-hepatic immune cells. Although AID may not be the direct cause of HCV-induced oncogenesis, AID expressed in B cells, not in hepatocytes, may prolong steatosis and cause increased lymphocyte infiltration into HCV core protein-induced liver lesions. Similarly, there was no difference in the time course of skin tumor development between the HPV8-Tg/AID (-/-) and HPV8-Tg/AID (+/+) groups. In conclusion, AID does not appear to be required for tumor development in the two virus-induced tumor mouse models tested although AID expressed in infiltrating B cells may promote inflammatory reactions in HCV core protein-induced liver pathogenesis.

Increased frequency of JC-polyomavirus detection in rheumatoid arthritis patients treated with multiple biologics.

Progressive multifocal leukoencephalopathy (PML) represents a rare but potentially fatal reactivation of JC-polyomavirus (JCPyV) recently also reported in patients with autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis (RA) treated with rituximab. The aim of the present study was to analyse the pattern of JCPyV infections in patients with RA undergoing treatment with biologic agents. Urine and blood samples were analysed from 80 patients for antibody levels and/or the presence of JCPyV DNA. Genotyping of the control region and VP1 was performed for all JCPyV DNA-positive specimens. Viremia of JCPyV was only temporarily detected in two patients, and these viruses did not carry any mutations associated with the occurrence of PML. JCPyV DNA was prevalent in initial urine samples of 33% of all patients. RA patients who have consecutively been treated with two or more biologic agents revealed significantly higher prevalence of JCPyV DNA in the urine compared to RA patients treated with their first biologic agent. The presence of JCPyV DNA in the urine closely correlated to JCPyV antibody positivity, and therefore, antibody titres were higher in RA patients who had consecutively received two or more biologic agents over time. Therefore, the overall number of biologic agents had an impact on the pattern of JCPyV detection in this study. Hence, JCPyV antibody screening might be useful as part of the PML risk stratification for RA patients in the future.

Resolution of novel human papillomavirus-induced warts after HPV vaccination.

Human papillomavirus (HPV) XS2 was isolated from warts on an immunosuppressed patient. After HPV vaccination, the warts resolved. HPVXS2 was also found in warts and normal skin of HIV-positive patients and rarely in HIV-negative controls. Further studies should elucidate the mechanisms that lead to wart clearance.

Case-control study of genus-beta human papillomaviruses in plucked eyebrow hairs and cutaneous squamous cell carcinoma.

Cutaneous human papillomaviruses (HPV) have been reported in cutaneous squamous cell carcinoma (SCC). We conducted a clinic-based case-control study to investigate the association between genus-beta HPV DNA in eyebrow hairs (EBH) and SCC. EBH from 168 SCC cases and 290 controls were genotyped for genus-beta HPV DNA. SCC tumors from a subset of cases (n = 142) were also genotyped. Viral load was determined in a subset of specimens positive for a single HPV type. Associations with SCC were estimated by odds ratios (OR) and 95% confidence intervals (CI) adjusted for age and sex using logistic regression. Statistical tests were two-sided. EBH DNA prevalence was greater in cases (87%) than controls (73%) (p < 0.05), and the association with SCC increased with the number of HPV types present, (≥ 4 types vs. HPV-negative: OR = 2.02, 95% CI = 1.07-3.80; p(trend) = 0.02). Type-specific associations were observed between SCC and DNA in EBH for HPV23 (OR = 1.90, 95% CI = 1.10-3.30) and HPV38 (OR = 1.84, 95% CI = 1.04-3.24). Additionally, when compared with the controls, the DNA prevalence in EBH was significantly higher among cases for 11 of the 25 genus-beta types tested, when accounting for DNA for the same HPV type in the tumor (ORs = 3.44-76.50). Compared to controls, the mean viral DNA load in EBH among the selected cases was greater for HPV5, HPV8 and HPV24, but lower for HPV38. SCC cases were more likely than controls to have HPV DNA+ EBH for single and multiple HPV types, providing additional support for the potential role of genus-beta HPV infections in SCC development.

Human polyomaviruses 6, 7, 9, 10 and Trichodysplasia spinulosa-associated polyomavirus in HIV-infected men.

Recently, several novel human polyomaviruses (HPyVs) have been detected. HPyV6, 7, 9 and 10 are not associated with any disease so far. Trichodysplasia spinulosa (TS)-associated polyomavirus (TSPyV) can cause the rare skin disease TS. We have evaluated cutaneous DNA prevalence and viral loads of five HPyVs in HIV-infected men compared to healthy male controls. 449 forehead swabs were analysed by HPyV-specific real-time PCR. HPyV6, HPyV7, TSPyV and HPyV10 were found significantly more frequently on the skin of 210 HIV-infected compared to 239 HIV-negative men (HPyV6, 39.0 vs 27.6 %; HPyV7, 21.0 vs 13.4 %; TSPyV, 3.8 vs 0.8 %; HPyV10, 9.3 vs 3.4 %; P<0.05, respectively). HPyV9 was not detected. Multiple infections were more frequent in HIV-positive men, but HPyV-DNA loads did not differ significantly in both groups. In contrast to HPyV6, 7 and 10, TSPyV and HPyV9 do not seem to be a regular part of the human skin microbiome.

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.

Human papillomavirus type 8 interferes with a novel C/EBPß-mediated mechanism of keratinocyte CCL20 chemokine expression and Langerhans cell migration.

Infection with genus beta human papillomaviruses (HPV) is implicated in the development of non-melanoma skin cancer. This was first evidenced for HPV5 and 8 in patients with epidermodysplasia verruciformis (EV), a genetic skin disease. So far, it has been unknown how these viruses overcome cutaneous immune control allowing their persistence in lesional epidermis of these patients. Here we demonstrate that Langerhans cells, essential for skin immunosurveillance, are strongly reduced in HPV8-positive lesional epidermis from EV patients. Interestingly, the same lesions were largely devoid of the important Langerhans cells chemoattractant protein CCL20. Applying bioinformatic tools, chromatin immunoprecipitation assays and functional studies we identified the differentiation-associated transcription factor CCAAT/enhancer binding protein ß (C/EBPß) as a critical regulator of CCL20 gene expression in normal human keratinocytes. The physiological relevance of this finding is supported by our in vivo studies showing that the expression patterns of CCL20 and nuclear C/EBPß converge spatially in the most differentiated layers of human epidermis. Our analyses further identified C/EBPß as a novel target of the HPV8 E7 oncoprotein, which co-localizes with C/EBPß in the nucleus, co-precipitates with it and interferes with its binding to the CCL20 promoter in vivo. As a consequence, the HPV8 E7 but not E6 oncoprotein suppressed C/EBPß-inducible and constitutive CCL20 gene expression as well as Langerhans cell migration. In conclusion, our study unraveled a novel molecular mechanism central to cutaneous host defense. Interference of the HPV8 E7 oncoprotein with this regulatory pathway allows the virus to disrupt the immune barrier, a major prerequisite for its epithelial persistence and procarcinogenic activity.

Tumor prevention in HPV8 transgenic mice by HPV8-E6 DNA vaccination.

The genus beta human papillomavirus 8 (HPV8) is involved in the development of cutaneous squamous cell carcinomas (SCCs) in individuals with epidermodysplasia verruciformis. Immunosuppressed transplant recipients are prone to harbor particularly high betapapillomavirus DNA loads, which may contribute to their highly increased risk of SCC. Tumor induction in HPV8 transgenic mice correlates with increased expression of viral oncogenes E6 and E2. In an attempt to prevent skin tumor development, we evaluated an HPV8-E6-DNA vaccine, which was able to stimulate a detectable HPV8-E6-specific cell-mediated immune response in 8/15 immunized mice. When skin of HPV8 transgenic mice was grafted onto non-transgenic littermates, the grafted HPV8 transgenic tissue was not rejected and papillomas started to grow within 14 days all over the transplant of 9/9 non-vaccinated and 7/15 not successfully vaccinated mice. In contrast, no papillomas developed in 6/8 successfully vaccinated mice. In the other two of these eight mice, a large ulcerative lesion developed within the initial papilloma growth or papilloma development was highly delayed. As the vaccine completely or partially prevented papilloma development without rejecting the transplanted HPV8 positive skin, the immune system appears to attack only keratinocytes with increased levels of E6 protein, which would give rise to papillomas.

Sensitive detection of viral transcripts in human tumor transcriptomes.

In excess of 12% of human cancer incidents have a viral cofactor. Epidemiological studies of idiopathic human cancers indicate that additional tumor viruses remain to be discovered. Recent advances in sequencing technology have enabled systematic screenings of human tumor transcriptomes for viral transcripts. However, technical problems such as low abundances of viral transcripts in large volumes of sequencing data, viral sequence divergence, and homology between viral and human factors significantly confound identification of tumor viruses. We have developed a novel computational approach for detecting viral transcripts in human cancers that takes the aforementioned confounding factors into account and is applicable to a wide variety of viruses and tumors. We apply the approach to conducting the first systematic search for viruses in neuroblastoma, the most common cancer in infancy. The diverse clinical progression of this disease as well as related epidemiological and virological findings are highly suggestive of a pathogenic cofactor. However, a viral etiology of neuroblastoma is currently contested. We mapped 14 transcriptomes of neuroblastoma as well as positive and negative controls to the human and all known viral genomes in order to detect both known and unknown viruses. Analysis of controls, comparisons with related methods, and statistical estimates demonstrate the high sensitivity of our approach. Detailed investigation of putative viral transcripts within neuroblastoma samples did not provide evidence for the existence of any known human viruses. Likewise, de-novo assembly and analysis of chimeric transcripts did not result in expression signatures associated with novel human pathogens. While confounding factors such as sample dilution or viral clearance in progressed tumors may mask viral cofactors in the data, in principle, this is rendered less likely by the high sensitivity of our approach and the number of biological replicates analyzed. Therefore, our results suggest that frequent viral cofactors of metastatic neuroblastoma are unlikely.

Human papillomavirus type 8 E6 oncoprotein inhibits transcription of the PDZ protein syntenin-2.

The E6 proteins from high-risk alpha human papillomavirus (HPV) types (e.g., HPV16) are characterized by the presence of a PDZ-binding motif through which they interact with a number of cellular PDZ domain-containing substrates and cooperate in their degradation. The ability of these E6 proteins to bind to PDZ domain proteins correlates with the oncogenic potential of the virus. The E6 proteins of oncogenic HPV from the genus Betapapillomavirus (betaPV, e.g., HPV8) do not encode a PDZ-binding motif. We found that the PDZ domain protein syntenin-2 is transcriptionally downregulated in primary human epidermal keratinocytes (PHEK) by HPV8 E6. The mRNA levels of the known HPV16 E6 PDZ protein targets Dlg, Scribble, Magi-1, Magi-3, PSD95, and Mupp1 were not changed by HPV8 E6. Decreased protein levels of syntenin-2 were observed in cell extracts from PHEK expressing HPV5, -8, -16, -20, and -38 E6 but not in HPV1 and -4 E6-positive keratinocytes. Surprisingly, HPV16 E6 also repressed transcription of syntenin-2 but with a much lower efficiency than HPV8 E6. In healthy human skin, syntenin-2 expression is localized in suprabasal epidermal layers. In organotypic skin cultures, the differentiation-dependent expression of syntenin-2 was absent in HPV8 E6- and E6E7-expressing cells. In basal cell carcinomas of the skin, syntenin-2 was not detectable, whereas in squamous cell carcinomas, expression was located in differentiated areas. Short hairpin RNA-mediated knockdown of syntenin-2 led to an inhibition of differentiation and an increase in the proliferation capacity in PHEK. These results identified syntenin-2 as the first PDZ domain protein controlled by HPV8 and HPV16 at the mRNA level.