Repurposing the Hybrid Capture 2 (HC2) screening test for whole-genome sequencing of human papillomaviruses.

Simple and standardized approaches for genome analysis of human papillomavirus (HPV) by next-generation sequencing are needed. The aim of the study was to develop a protocol for direct deep sequencing of high-risk (hr) HPV strains, based on the widely used commercial Hybrid Capture 2 (QIAGEN) test, without any additional probe design. This protocol was applied to 15 HPV-positive and two HPV-negative cervical samples or cell lines and validated at the genotype level by comparing the sequencing results to those obtained using a commercial genotyping kit. The performance of our protocol, presented in this proof-of-principle study, supports its use for accurate characterization of genetic variants of hrHPV.

Differential HPV16 variant distribution in squamous cell carcinoma, adenocarcinoma and adenosquamous cell carcinoma.

Human Papillomavirus 16 (HPV16) causes 70% of invasive cervical cancers (ICC) worldwide. Interaction between HPV16 genetic diversity, host genetics and target tissue largely determine the chances to trigger carcinogenesis. We have analyzed the differential prevalence of viral variants in 233 HPV16-monoinfected squamous (SCC), glandular (ADC) and mixed (ADSC) ICCs from four continents, assessing the contribution of geographical origin and cancer histology. We have further quantified the contribution of viral variants and cancer histology to differences in age at tumor diagnosis. The model fitted to the data explained 97% of the total variance: the largest explanatory factors were differential abundance among HPV16 variants (78%) and their interaction with cancer histology (9.2%) and geography (10.1%). HPV16_A1-3 variants were more prevalent in SCC while HPV16_D variants were increased in glandular ICCs. We confirm further a non-random geographical structure of the viral variants distribution. ADCs were diagnosed at younger ages than SCCs, independently of the viral variant triggering carcinogenesis. HPV16 variants are differentially associated with histological ICCs types, and ADCs are systematically diagnosed in younger women. Our results have implications for the implementation of cervical cancer screening algorithms, to ensure proper early detection of elusive ADCs.

Disagreement in high-grade/low-grade intraepithelial neoplasia and high-risk/low-risk HPV infection: clinical implications for anal cancer precursor lesions in HIV-positive and HIV-negative MSM.

Anal condylomata are common in HIV-positive individuals and among men who have sex with men (MSM). Generally attributable to infection by low-risk human papillomaviruses (HPVs), condylomata are considered benign low-grade squamous intraepithelial lesions (SILs). However, anal condylomata have occasionally been linked to high-grade SIL and to oncogenic, high-risk HPVs. Here we describe the range of intraepithelial lesions and of the associated HPVs in heterosexual men and women and MSM. Perianal and anal condylomata were collected from 243 patients (56 heterosexual women, 61 heterosexual men and 126 MSM, including 41 HIV-positive MSM). We assessed lesion histology and HPV genotype. Prevalence estimates and Poisson models were used. Irrespective of HIV infection status, MSM showed a higher proportion of condylomata as high-grade SILs compared to heterosexual men/women. High-grade SILs were also more prevalent in anal than in perianal lesions in all patient groups. HIV-positive MSM exhibited increased prevalence ratio (4.6; 95% confidence interval 2.1-10.0) of perianal low-grade SILs containing only high-risk HPVs compared to HIV-negative MSM. In addition, more than 64% of anal SILs with a high-grade component, regardless of HIV infection, were exclusively associated with low-risk HPVs. In anal condylomata, both high-grade and low-grade SILs can be associated with high-risk and/or low-risk HPVs. Particularly, low-grade perianal SILs associated with high-risk HPVs were common in HIV-positive MSM, while presence of only low-risk HPVs in high-grade SILs were common in both MSM groups. Our findings sound a note of caution for the common clinical practice for the treatment of anal condylomata as benign lesions in MSM and HIV-positive patients.

Large contribution of human papillomavirus in vaginal neoplastic lesions: a worldwide study in 597 samples.

AIM: This work describes the human papillomavirus (HPV) prevalence and the HPV type distribution in a large series of vaginal intraepithelial neoplasia (VAIN) grades 2/3 and vaginal cancer worldwide. METHODS: We analysed 189 VAIN 2/3 and 408 invasive vaginal cancer cases collected from 31 countries from 1986 to 2011. After histopathological evaluation of sectioned formalin-fixed paraffin-embedded samples, HPV DNA detection and typing was performed using the SPF-10/DNA enzyme immunoassay (DEIA)/LiPA25 system (version 1). A subset of 146 vaginal cancers was tested for p16(INK4a) expression, a cellular surrogate marker for HPV transformation. Prevalence ratios were estimated using multivariate Poisson regression with robust variance. RESULTS: HPV DNA was detected in 74% (95% confidence interval (CI): 70-78%) of invasive cancers and in 96% (95% CI: 92-98%) of VAIN 2/3. Among cancers, the highest detection rates were observed in warty-basaloid subtype of squamous cell carcinomas, and in younger ages. Concerning the type-specific distribution, HPV16 was the most frequently type detected in both precancerous and cancerous lesions (59%). p16(INK4a) overexpression was found in 87% of HPV DNA positive vaginal cancer cases. CONCLUSIONS: HPV was identified in a large proportion of invasive vaginal cancers and in almost all VAIN 2/3. HPV16 was the most common type detected. A large impact in the reduction of the burden of vaginal neoplastic lesions is expected among vaccinated cohorts.

Interlaboratory reproducibility and proficiency testing within the human papillomavirus cervical cancer screening program in Catalonia, Spain.

In Catalonia, a screening protocol for cervical cancer, including human papillomavirus (HPV) DNA testing using the Digene Hybrid Capture 2 (HC2) assay, was implemented in 2006. In order to monitor interlaboratory reproducibility, a proficiency testing (PT) survey of the HPV samples was launched in 2008. The aim of this study was to explore the repeatability of the HC2 assay's performance. Participating laboratories provided 20 samples annually, 5 randomly chosen samples from each of the following relative light unit (RLU) intervals: <0.5, 0.5 to 0.99, 1 to 9.99, and ≥10. Kappa statistics were used to determine the agreement levels between the original and the PT readings. The nature and origin of the discrepant results were calculated by bootstrapping. A total of 946 specimens were retested. The kappa values were 0.91 for positive/negative categorical classification and 0.79 for the four RLU intervals studied. Sample retesting yielded systematically lower RLU values than the original test (P<0.005), independently of the time elapsed between the two determinations (median, 53 days), possibly due to freeze-thaw cycles. The probability for a sample to show clinically discrepant results upon retesting was a function of the RLU value; samples with RLU values in the 0.5 to 5 interval showed 10.80% probability to yield discrepant results (95% confidence interval [CI], 7.86 to 14.33) compared to 0.85% probability for samples outside this interval (95% CI, 0.17 to 1.69). Globally, the HC2 assay shows high interlaboratory concordance. We have identified differential confidence thresholds and suggested the guidelines for interlaboratory PT in the future, as analytical quality assessment of HPV DNA detection remains a central component of the screening program for cervical cancer prevention.

Phylogenetically related, clinically different: human papillomaviruses 6 and 11 variants distribution in genital warts and in laryngeal papillomatosis.

Genital warts (GWs) and laryngeal papillomatosis (LP) are two usually benign pathologies related to infection with human papillomaviruses (HPVs), mainly HPV6 and HPV11. The aim of this work was to describe the genetic diversity of HPV6 and HPV11 isolates found in GWs and LPs, and to analyse the differential involvement of viral variants in either lesion. A total of 231 samples diagnosed as GWs (n = 198) or LP (n = 33) and caused by HPV6 or HPV11 monoinfections were analysed. The phylogenetic relationships of the retrieved viral sequences were explored. We have identified the long control region and the intergenic E2-L2 region as the two most variable regions in both HPV6 and HPV11 genomes. We have generated new HPV6 (n = 166) or HPV11 (n = 65) partial sequences from GWs and LPs lesions spanning both regions and studied them in the context of all available sequences of both types (final n = 412). Our results show a significant (p <0.01) differential presence of HPV6 variants among both pathologies, with HPV6 B variants being preferentially found in GW versus LP samples. No differential involvement of HPV11 variants was observed. Our findings suggest that different HPV6 variants may either show differential tropism or have different potential to induce lesions in different epithelia.

Differential presence of Papillomavirus variants in cervical cancer: an analysis for HPV33, HPV45 and HPV58.

BACKGROUND: Certain human papillomaviruses (HPVs) are the causative agents of cervical carcinomas in humans. The identification of the link between infection and cancer has resulted in the successful establishment of clinical strategies such as screening or vaccination programs, aiming to prevent this pathology. More than 150 different HPVs have been described and classified and the large majority of them are not related to cancer. The genus Alphapapillomavirus encompasses many PVs, some of which are identified in humans as oncogenic, according to the epidemiological connection between infection and cervical cancer. Variants of some of these "high-risk" HPVs may have an increased involvement in cervical cancer, although definitive data are still wanting. The aim of the present work was to analyze the presence of HPV33, HPV45 and HPV58 variants in cases of cervical cancer. METHODS: Samples from cervical lesions in the context of different cervical cancer surveys were analyzed for presence of HPV DNA. Samples positive for HPV33, HPV45 or HPV58 DNA were selected and the E6/E7 genes were amplified and sequenced. The phylogenetic relationships of these sequences were inferred using an evolutionary placement algorithm and accordingly classified at the variant level. RESULTS: All viral E6/E7 sequences were successfully placed in the classification schemes of the corresponding viruses. For HPV33 (n=23), 45 (n=61) or 58 (n=29), the distribution of variants found in cases of cervical cancer is not a random sample of the corresponding diversity. In all three HPVs, the respective A variants were more prevalent in the viral DNA-positive cases of cervical cancer analyzed. This is the first study trying to discern the phylogenetic connection between variants of the oncogenic HPV33, 45 and 58, and squamous cell carcinoma of the cervix.

Bead-based multiplex genotyping of 58 cutaneous human papillomavirus types.

Cutaneous human papillomaviruses (HPVs) are a heterogeneous, nonmonophyletic assembly, comprising about 50 characterized types and at least 133 isolates putatively representing new types. Their natural history of infection and potential association with nonmelanoma skin cancer are not well understood. Several PCR systems have been developed that amplify a broad spectrum of cutaneous HPVs. However, amplicon genotyping by sequencing or reverse line blot assays are complex and not well suited for high-throughput analyses. We developed a novel multiplex cutaneous papillomavirus genotyping (McPG) assay for 38 defined and 20 putative cutaneous HPVs of the beta, gamma, mu, and nu genera. Viral DNA was amplified by the use of a modified single-tube nested "hanging-droplet" FAP PCR. The amplifiable papillomavirus (PV) spectrum was enlarged by the use of 9 outer and 13 inner primers. Biotinylated PCR products were hybridized to type-specific oligonucleotide probes coupled to fluorescence-labeled polystyrene beads and analyzed using Luminex technology. Analytical sensitivity was analyzed for 38 defined HPVs and was ≤100 genome copies for all types. Integrated ß-globin primers allow for simultaneous DNA quality control. McPG is characterized by high reproducibility (κ= 0.84, 95% confidence interval = 0.79 to 0.88), good concordance with the original nested FAP PCR, followed by sequencing (70.2% complete or partial agreement) when 322 skin biopsy DNA samples were analyzed, and improved ability to detect multiple infections (on average 2.5 HPV types per HPV-positive sample compared to 1.7 HPV types with nested FAP-PCR). In conclusion, McPG is a powerful tool for genotyping multiple cutaneous HPVs in a high-throughput format and is thus suitable for large-scale epidemiological studies.

Bead-based multiplex genotyping of human papillomaviruses.

Typing of human papillomaviruses (HPV) by DNA hybridization procedures, such as reverse line blot (RLB) assay, is sensitive and well validated. However, the application of these assays to high-throughput analyses is limited. Here, we describe the development of multiplex human papillomavirus genotyping (MPG), a quantitative and sensitive high-throughput procedure for the identification of multiple high- and low-risk genital HPV genotypes in a single reaction. MPG is based on the amplification of HPV DNA by a general primer PCR (GP5+/6+) and the subsequent detection of the products with type-specific oligonucleotide probes coupled to fluorescence-labeled polystyrene beads (Luminex suspension array technology). Up to 100 different HPV types can be detected simultaneously with MPG, and the method is fast and labor saving. We detected all 22 HPV types examined with high specificity and reproducibility (the median interplate coefficient of variation was below 10%). Detection limits for the different HPV types varied between 100 and 800 pg of PCR products. We compared the performance of MPG to an established RLB assay on GP5+/6+-PCR products derived from 94 clinical samples. The evaluation showed an excellent agreement (kappa = 0.922) but also indicated a higher sensitivity of MPG. In conclusion, MPG appears to be highly suitable for large-scale epidemiological studies and vaccination trials as well as for routine diagnostic purposes.

The E5 protein of the human papillomavirus type 16 modulates composition and dynamics of membrane lipids in keratinocytes.

The E5 protein of the human papillomavirus type 16 is a small protein found associated to membranes, mainly in the Golgi apparatus, and expressed in the early stages of viral infection. Its expression modifies the cell response towards growth factors and stress exposures, and also blocks the surface expression of MHC molecules. A global explanation for these multiple effects is hitherto not available. Here we present data showing that the expression of HPV16-E5 increases the amount of free cholesterol readily extractable from the plasma membrane, without altering the total cholesterol content. In addition, HPV16-E5 modifies the composition of the cell membranes, increasing the synthesis rate of phosphatidylcholine and phosphatidylserine, while diminishing that of phosphatidylglycerol. We propose that these changes in the lipid composition of the membrane are the central effect of HPV16-E5 on the cell. The multiple and apparently disconnected effects of HPV16-E5 on tyrosine-kinase receptors, induction of the apoptosis and impairment of MHC trafficking could follow the initial alteration on the membrane composition.