A novel genital human papillomavirus (HPV), HPV type 74, found in immunosuppressed patients

A rigorous exploration of anal HPV genotypes using a next-generation sequencing (NGS) approach in HIV-infected men who have sex with men at risk for developing anal cancer

BACKGROUND

There are no HPV-based measures for managing anal cancer (AC) in HIV-infected (HIV+) men who have sex with men (MSM) because of the high positivity of high-risk (HR)-HPVs. As next-generation sequencing (NGS) is able to describe the composition of HPVs as percent (%) reads rather than positive vs negative results, we used NGS approach to detect HPVs in anal samples of HIV+ MSM to test its ability to differentiate those who are diagnosed with atypical squamous cells of unknown significance or greater (ASCUS+) from those who are free of such lesions and to understand the burden of HPV infections in relation to HPV vaccines.

METHODS

Study included 81 HIV+ MSM characterized for demographics, patient-reported outcome measures, HIV related laboratory measures and anal cytology. We summarized NGS HPV data using % read cut points (>0%->30%) and tested the relationship between % reads of HR-HPVs and risk of ASCUS+ using logistic regression.

RESULTS

Forty-six HPVs were detected at the >0% read cut point. The prevalence of any HR-HPVs varied from 100% to 40% with >0% to >30% reads while ≥99% were infected with HR-HPVs included or not included in the 9 valent HPV vaccine at the >0% read cut point. MSM with >30% HR-HPV reads were 4.5 times more likely to be diagnosed with ASCUS+ compared to ≤30% reads (P = .033).

CONCLUSION

NGS-based approach is more accurate than PCR-based HPV testing for identifying HIV+ MSM at risk for developing AC. We raise the concern regarding the efficacy of current HPV vaccines for preventing AC in this high-risk population.

Molecular characterisation of genital human papillomavirus among women in Southwestern, Nigeria

Background

Persistent infections with high-risk genital Human papillomavirus (HPV) especially types 16 and 18, are associated with cervical cancer. However, distribution of HPV types varies greatly across geographical regions and the available vaccines target only few types. This study was designed to determine the HPV types circulating in Southwestern Nigeria, thereby providing necessary information for effective control of the virus.

Methods

Endocervical swab samples were collected from a total of 295 consenting women attending routine cervical cancer screening, STI clinics and community-based outreach programme. Viral DNA was extracted from the samples and the consensus region of the HPV DNA was amplified by PCR using GP-E6/E7 primers. Type-specific nested multiplex PCR and Sanger sequencing were used to genotype the HPV isolates.

Results

In this study, 51 (17.3%) individuals were positive for HPV DNA using consensus primers that target the E6/E7 genes but only 48 (16.3%) were genotyped. A total of 15 HPV types (HPV-6, 16, 18, 31, 33, 35, 42, 43, 44, 52, 58, 66, 74, 81, 86) were detected, with HPV-31 being the most predominant (32.8%), followed by HPV-35 (17.2%) and HPV-16 (15.5%). Two rare HPV types; 74 and 86 were also detected. The HPV-74 isolate had three nucleotide (CCT) insertions at E7 gene that translated into amino acid proline. Highest nucleotide substitutions (n = 32) were found in HPV-44 genotype. Among positive individuals, 20.8% had dual infections and 86.2% had High-risk HPV types.

Conclusions

Multiple Human papillomavirus types co-circulated in the study. Most of the circulating Human papillomavirus are high-risk type with type 31 being the most predominant. Although the implication of HPV-74 with proline insertion detected for the first time is unknown, it may have effect on the transformation potential of the virus. Polyvalent HPV vaccine will be more effective for the infection control in Nigeria.

Computational identification, characterization and validation of potential antigenic peptide vaccines from hrHPVs E6 proteins using immunoinformatics and computational systems biology approaches

High-risk human papillomaviruses (hrHPVs) are the most prevalent viruses in human diseases including cervical cancers. Expression of E6 protein has already been reported in cervical cancer cases, excluding normal tissues. Continuous expression of E6 protein is making it ideal to develop therapeutic vaccines against hrHPVs infection and cervical cancer. Therefore, we carried out a meta-analysis of multiple hrHPVs to predict the most potential prophylactic peptide vaccines. In this study, immunoinformatics approach was employed to predict antigenic epitopes of hrHPVs E6 proteins restricted to 12 Human HLAs to aid the development of peptide vaccines against hrHPVs. Conformational B-cell and CTL epitopes were predicted for hrHPVs E6 proteins using ElliPro and NetCTL. The potential of the predicted peptides were tested and validated by using systems biology approach considering experimental concentration. We also investigated the binding interactions of the antigenic CTL epitopes by using docking. The stability of the resulting peptide-MHC I complexes was further studied by molecular dynamics simulations. The simulation results highlighted the regions from 46–62 and 65–76 that could be the first choice for the development of prophylactic peptide vaccines against hrHPVs. To overcome the worldwide distribution, the predicted epitopes restricted to different HLAs could cover most of the vaccination and would help to explore the possibility of these epitopes for adaptive immunotherapy against HPVs infections.

HPV genotypes detected by linear array and next-generation sequencing in anal samples from HIV positive men who have sex with men in Mexico

The incidence of anal cancer has been rising, especially in HIV+ patients and has been associated with HPV infection. HIV+ patients are more at risk of HPV coinfection and are seven times more likely to have persistent HPV infection; moreover, HIV+ men have an increased risk of developing anal cancer compared to HIV+ women. The development of screening strategies for the detection of HPV in HIV+ men is of major importance; however, there is not enough information about the HPV genotypes and variants that are colonizing the anal epithelia of HIV+ men in diverse geographical regions. Therefore, this work was aimed at identifying HPV genotypes present in the anal epithelium of HIV+ men who have sex with men (MSM), with or without anal lesions (n = 75). For HPV genotyping, two approaches were performed: Linear Array HPV Genotyping Test and next-generation sequencing (NGS). In general, the six most frequent HPV genotypes found by Linear Array were HPV6, 62, 61, 81, 16 and 51. On the other hand, employing NGS, a total of 36 HPV genotypes belonging to both alpha and beta genera were found. The genotypes with the greatest number of reads, according to the diagnostic group, were: HPV81, 45, 6, 51 and 61 in MSM without anal lesions (WAIN); HPV6, 61, 70, 62 and 66 in MSM with atypical lesions (AAL); HPV6, 11, 66, 81 and 61 in MSM with anal intraepithelial neoplasia grade I (AIN I); and HPV16, 81, 58, 61 and 52 with AIN III. Additionally, a great diversity of L1 variants was observed, especially in genotypes HPV16, 58, 61, 52, 45 and 59.

Human papillomavirus genotyping by Linear Array and Next-Generation Sequencing in cervical samples from Western Mexico

BACKGROUND

The Linear Array® (LA) genotyping test is one of the most used methodologies for Human papillomavirus (HPV) genotyping, in that it is able to detect 37 HPV genotypes and co-infections in the same sample. However, the assay is limited to a restricted number of HPV, and sequence variations in the detection region of the HPV probes could give false negatives results. Recently, 454 Next-Generation sequencing (NGS) technology has been efficiently used also for HPV genotyping; this methodology is based on massive sequencing of HPV fragments and is expected to be highly specific and sensitive. In this work, we studied HPV prevalence in cervixes of women in Western Mexico by LA and confirmed the genotypes found by NGS.

METHODS

Two hundred thirty three cervical samples from women Without cervical lesions (WCL, n = 48), with Cervical intraepithelial neoplasia grade 1 (CIN I, n = 98), or with Cervical cancer (CC, n = 87) were recruited, DNA was extracted, and HPV positivity was determined by PCR amplification using PGMY09/11 primers. All HPV- positive samples were genotyped individually by LA. Additionally, pools of amplicons from the PGMY-PCR products were sequenced using 454 NGS technology. Results obtained by NGS were compared with those of LA for each group of samples.

RESULTS

We identified 35 HPV genotypes, among which 30 were identified by both technologies; in addition, the HPV genotypes 32, 44, 74, 102 and 114 were detected by NGS. These latter genotypes, to our knowledge, have not been previously reported in Mexican population. Furthermore, we found that LA did not detect, in some diagnosis groups, certain HPV genotypes included in the test, such as 6, 11, 16, 26, 35, 51, 58, 68, 73, and 89, which indicates possible variations at the species level.

CONCLUSIONS

There are HPV genotypes in Mexican population that cannot be detected by LA, which is, at present, the most complete commercial genotyping test. More studies are necessary to determine the impact of HPV-44, 74, 102 and 114 on the risk of developing CC. A greater number of samples must be analyzed by NGS for the most accurate determination of Mexican HPV variants.

In silico mechanistic analysis of IRF3 inactivation and high-risk HPV E6 species-dependent drug response

The high-risk human papillomavirus E6 (hrHPV E6) protein has been widely studied due to its implication in cervical cancer. In response to viral threat, activated kinases phosphorylate the IRF3 autoinhibitory domain, inducing type1 interferon production. HPV circumvents the antiviral response through the possible E6 interaction with IRF3 and abrogates p53's apoptotic activity by recruiting E6-associated protein. However, the molecular mechanism of IRF3 inactivation by hrHPV E6 has not yet been delineated. Therefore, we explored this mechanism through in silico examination of protein-protein and protein-ligand docking, binding energy differences, and computational alanine mutagenesis. Our results suggested that the LxxLL motifs of IRF3 binds within the hydrophobic pocket of E6, precluding Ser-patch phosphorylation, necessary for IRF3 activation and interferon induction. This model was further supported by molecular dynamics simulation. Furthermore, protein-ligand docking and drug resistance modeling revealed that the polar patches in the pocket of E6, which are crucial for complex stability and ligand binding, are inconsistent among hrHPV species. Such variabilities pose a risk of treatment failure owing to point mutations that might render drugs ineffective, and allude to multi-drug therapy. Overall, this study reveals a novel perspective of innate immune suppression in HPV infections and suggests a plausible therapeutic intervention.

Human papillomavirus typing by single tube multiplex amplification in real time (SMART): the PapillomaFinder® SMART 20 assay

BACKGROUND

High-risk (hr) human papillomavirus (HPV) infections play a causal role in the development of cervical cancer. The detection of hrHPV is, therefore, advocated in cervical cancer screening programs.

OBJECTIVES

The aim of this study was to determine the performance of a novel HPV typing assay, PapillomaFinder® SMART 20. This is a one-tube-per-sample method, to be performed on standard real-time PCR platforms, using melting curve analysis to distinguish targets. The assay detects all 14 hrHPV types, of which 16, 18, 31, 33, 35, 39, 45, 52, 56 and 58 individually. HrHPV types 51, 59, 66 and 68 are detected in an hrHPV pool, and low-risk (lr) HPV types 6, 11, 40, 42, 43 and 44 in an lrHPV pool.

STUDY DESIGN

The method was tested on HPV plasmid models, WHO and QCMD proficiency panels and a series of clinical cytological samples (n=45), the latter in comparison with a clinically validated real-time quantitative PCR.

RESULTS

Type-specificity of the test was 100% using plasmids, the WHO and QCMD panels. Sensitivity for hrHPV in single infections was 100% using the WHO and QCMD panels and cytological samples, with an analytical sensitivity of 10-25 copies per reaction for all HPV types tested. Of the 34 HPV types present in the 8 multiple infections in the WHO panel, 30 were detected. In all cytological samples at least one hrHPV type was found, in concordance with the clinically validated method. Only when the viral load of the dominant HPV types in multiple infections greatly exceeded that of the other types in the infection, those other types were not always detected.

CONCLUSIONS

PapillomaFinder® SMART 20 is a rapid, easy to perform, single tube HPV typing assay. The assay detects the 14 hrHPV types, and the 6 most important lrHPV types with a high sensitivity and type-specificity.

HPV Prevalence and Detection of Rare HPV Genotypes in Hong Kong Women from Southern China with Cytological Abnormalities

Human papillomavirus (HPV) has been identified as the primary cause of cervical squamous intraepithelial lesion and invasive cervical cancer. The emergence of various commercial HPV genotyping kits with different characteristics facilitates the detection of most high-risk and low-risk HPV genotypes, but the rare HPV types are usually underdiagnosed. In the present study, HPV detection was performed using the GenoFlow HPV Array Test kit (DiagCor Bioscience), which can identify 33 HPV subtypes by specific probes. Besides, a HPV consensus probe (universal probe) was designed to capture not only the 33 genotypes but also rare subtypes. Of the 1643 Southern Chinese women tested between 2012 and 2013, the HPV prevalence was 42.3%, with HPV 52 (139/1643, 8.5%), HPV 81 (89/1643, 5.4%), and HPV 16 (63/1643, 3.8%) being the most frequent subtypes detected. Among all 695 HPV-positive cases, 56 (8.1%) cases were only detected by the universal probe, in which 5 were either ASCUS or LSIL cases. Sequencing results confirmed HPV types 30, 91, and 74, and the intratypic variants of HPV 72 and 82 were present in the 5 cases. The result suggests that some rare HPV subtypes might be involved in cervical lesions.

Prevalence of low-risk HPV types and genital warts in women born 1988/89 or 1983/84 -results of WOLVES, a population-based epidemiological study in Wolfsburg, Germany

BACKGROUND

Wolfsburg HPV Epidemiological Study (WOLVES) is a population-based cohort study on HPV infections and associated diseases in the pre-vaccination era in young women in Wolfsburg, Germany.

METHODS

Women born 1983/84 or 1988/89 were invited to participate. Participants were recruited in gynecology practices, and completed a questionnaire with socioeconomic, sexual and medical data including vaccination status. Pelvic examination with Pap smear and HPV testing (HC2 = Hybrid Capture 2) was obligatory. HC2-positive and 10% of HC2-negative samples were tested for specific HPV types with SPF-10-PCR, and in inconclusive cases with DNA sequencing. Women with genital warts (GW) and those with atypical Pap smears were transferred for colposcopy. GWs were classified as typical condylomata acuminata (TCA), flat condyloma (FC) and seborrheic wart-like (SWL).

RESULTS

In total, 1258 subjects were recruited from the target population of 2850 (44.1%). Overall the prevalence of HC2 low-risk (LR) types was 8.5%. HPV6 was the most frequent LR type (2.1%), followed by HPV42 (1.1%), HPV11 and HPV44 (each 0.4%). LiPA showed a low sensitivity for HPV types 42, 90 and 91, which were detected only by HC2 and HPV sequencing. Nine women (0.7%) were transferred with incident GW: five TCA, two FC and two SWL. All TCA were associated with HPV6 in corresponding cervical swabs and warts. Tissues of SWL contained HPV6 (n = 1) and HPV16 (n = 1). The cumulative life-risk for GW was 1.4% in the 1988/89 and 4.8% in the 1983/84 cohort. Eight of 107 HC2-LR + and five of nine cases of GW had concomitant abnormal Pap smears. All CIN lesions could be linked to high-risk HPV types but borderline and low-grade abnormal smears were explained by vaginal and cervical TCA in four cases.

CONCLUSIONS

HC2 was a specific test for the detection of established and potential LR types. In this first WOLVES analysis, HPV6 was the most frequent HPV type and the single LR type linked to disease. The observed GW incidence of 715 per 100,000 fits well with estimates of healthcare providers. Although life risks for GW were lower than in Scandinavian analyses, the societal burden within the WOLVES populations was considerable.

Prevalence of human papillomavirus in Indonesia: a population-based study in three regions

Cervical cancer is the most common cancer among women in the Indonesian population, yet little is known about the prevalence of human papillomavirus (HPV). We investigated age-specific prevalence of HPV types and possible risk factors of HPV positivity in a population-based sample of 2686 women, aged 15–70 years, in Jakarta, Tasikmalaya, and Bali, Indonesia. The overall HPV prevalence was 11.4%, age-standardized to the world standard population 11.6%. The most prevalent types found were HPV 52, HPV 16, HPV 18, and HPV 39, respectively, 23.2, 18.0, 16.1, and 11.8% of the high-risk HPV types. In 20.7% of infections, multiple types were involved. Different age-specific prevalence patterns were seen: overall high in Jakarta, and in Tasikmalaya, and declining with age in Bali. The number of marriages was most associated with HPV positivity (OR 1.81 95% CI 1.31–2.51)). Remarkably, in Indonesia HPV 16 and HPV 18 are equally common in the general population, as they are in cervical cancer. HPV 52 was the most prevalent type in the general population, suggesting that this type should be included when prophylactic HPV vaccination is introduced in Indonesia.

Structures of a human papillomavirus (HPV) E6 polypeptide bound to MAGUK proteins: mechanisms of targeting tumor suppressors by a high-risk HPV oncoprotein

Human papillomavirus (HPV) E6 oncoprotein targets certain tumor suppressors such as MAGI-1 and SAP97/hDlg for degradation. A short peptide at the C terminus of E6 interacts specifically with the PDZ domains of these tumor suppressors, which is a property unique to high-risk HPVs that are associated with cervical cancer. The detailed recognition mechanisms between HPV E6 and PDZ proteins are unclear. To understand the specific binding of cellular PDZ substrates by HPV E6, we have solved the crystal structures of the complexes containing a peptide from HPV18 E6 bound to three PDZ domains from MAGI-1 and SAP97/Dlg. The complex crystal structures reveal novel features of PDZ peptide recognition that explain why high-risk HPV E6 can specifically target these cellular tumor suppressors for destruction. Moreover, a new peptide-binding loop on these PDZs is identified as interacting with the E6 peptide. Furthermore, we have identified an arginine residue, unique to high-risk HPV E6 but outside the canonical core PDZ recognition motif, that plays an important role in the binding of the PDZs of both MAGI-I and SAP97/Dlg, the mutation of which abolishes E6's ability to degrade the two proteins. Finally, we have identified a dimer form of MAGI-1 PDZ domain 1 in the cocrystal structure with E6 peptide, which may have functional relevance for MAGI-1 activity. In addition to its novel insights into the biochemistry of PDZ interactions, this study is important for understanding HPV-induced oncogenesis; this could provide a basis for developing antiviral and anticancer compounds.

The use of nested polymerase chain reaction and restriction fragment length polymorphism for the detection and typing of mucosal human papillomaviruses in samples containing low copy numbers of viral DNA

Mucosal human papillomaviruses (HPVs) that infect the genital area have also been shown to infect the oral cavity. In this study a restriction fragment length polymorphism (RFLP) method was developed on a nested polymerase chain reaction (PCR) product to identify ten high risk HPV types 16, 18, 31, 33, 35, 45, 51, 52, 58 and 59 as well as the low risk HPV 11. HPV DNA was detected in 23/31 (74%) of buccal specimens using a sensitive nested PCR employing degenerate consensus primers (Williamson and Rybicki, 1991). Consensus PCR using the PGMy09/11 primers. was able to detect HPV in only 29% of the specimens that had tested positive using the nested HPV PCR primers. HPV 11 type specific primers detected HPV 11 DNA in only 66% of the specimens showing HPV 11 DNA by means of nested PCR and RFLP. A Genbank search revealed that the PCR primers could detect a wide range of mucosal HPV types including types HPV 70, 72 and 73 which have all been isolated from immunocompromised patients. Of the 23 buccal specimens that were positive for HPV DNA, 13 were single infections, five were dual infections and three were triple infections. The HPV types identified by RFLP were: HPV 11 (18/23), HPV 18 (8/23), HPV 16 (3/23), and HPV 33 (1/23). HPV 13 (2/23) was identified by direct sequencing of the inner amplicon of the PCR product.

Human papillomavirus: a review

Human papillomavirus infection remains a great source of morbidity and mortality. Progress in understanding the structure of HPV and its pathogenesis has led to a wide variety of possible new treatment modalities to combat HPV-related disease. Most HPV infections (whether high risk or low risk) resolve without any medical intervention. Persistent or progressive disease, however, remains difficult to treat. Although currently available therapies have proved efficacious and tolerable in the treatment of nongenital and genital warts, no single therapy is uniformly effective in eradicating persistent HPV infection. Cytodestructive methods, such as cryotherapy, remain the primary treatment modality for nongenital warts. Immune response modifiers, such as imiquimod, currently show the greatest promise in treating HPV-induced anogenital lesions, both with respect to complete response and in preventing recurrence. Human papillomavirus infection is one of the most common sexually transmitted diseases in the world, and cervical cancer still causes significant morbidity and mortality. Pap smear tests have greatly reduced the incidence and mortality of cervical cancer in developed countries. Additional research will focus on primary and secondary prevention strategies. Vaccines against high-risk HPV types are promising modalities currently under investigation to prevent HPV infections and possibly to treat them.

Identification of six putative novel human papillomaviruses (HPV) and characterization of candidate HPV type 87

Six putative novel human papillomavirus (HPV) types were detected by using general primers for a conserved L1 HPV region in patients examined in gynecologic centers. One of the isolates, detected in samples from 4 patients with koilocytic atypia at cervical cytology (3 of whom were also infected with human immunodeficiency virus type 1), was completely sequenced, identified as a new HPV genotype, and designated candidate HPV87 (candHPV87) by the Reference Center for Human Papillomavirus. candHPV87 shows the classic HPV genome organization and the absence of a functional E5 coding region. Phylogenetic analysis documented that the candHPV87 genome clusters within the A3 group of HPVs, together with HPV61, HPV72, HPV83, HPV84 and candHPV86, which have been completely sequenced, and a number of other putative novel genotypes (two of which are described in this work), which have been partially characterized. To address the growth-enhancing potential of candHPV87, the E6 and E7 putative coding regions were cloned and expressed in tissue cultures. The data indicate that both proteins stimulate cell division in tissue cultures more than those of low-risk HPVs, though not as much as those of HPV16. Taken together, the clinical, molecular, and biological data suggest that the novel papillomavirus characterized in the present study is a low- to intermediate-risk HPV.

Papilomavírus humano associado a lesões de cérvice uterina

Estudou-se a prevalência do papilomavírus humano (HPV) em 228 mulheres portadoras de lesões em cérvice uterina, atendidas no Instituto Ofir Loiola, em Belém, Pará, no período de março de 1992 a maio de 1996. As pacientes foram submetidas à biópsia de colo uterino, sendo o material encaminhado para histopatologia e pesquisa de HPV por PCR e hibridização por dot-blot. Distribuíram-se as participantes em três grupos, conforme diagnóstico histopatológico. O grupo A constituiu-se de 155 mulheres com carcinoma epidermóide invasor ou com adenocarcinoma, o grupo B de 54 portadoras de neoplasia intra-epitelial cervical grau II ou III, e o grupo C de 19 pacientes com cervicite crônica. Observaram-se prevalências de HPV em 70,3%, 63,0% e 36,8% das mulheres dos grupamentos A, B e C, respectivamente, sendo o HPV 16 registrado em 60,4% das amostras positivas do grupo A e 54,5% daquelas do grupo B. Os tipos 16, 18 e 33 representaram 71,4% dos detectados no grupo C.

A two-tier polymerase chain reaction direct sequencing method for detecting and typing human papillomaviruses in pathological specimens

An in-house polymerase chain reaction direct sequencing (PCR-DS) approach for HPV detection and typing was developed, taking advantage of two widely used pairs of human papillomavirus (HPV)-specific PCR primers, MY09/MY11 and GP5/GP6, and 33P-labeled dideoxynucleotides. In this study, 105 pathological specimens were examined: 89% were diagnosed as cervical intraepithelial neoplasia (CIN) grade I-III, 76.2% were HPV-positive by PCR-DS. The PCR using GP5/GP6 (first tier) and MY09/MY11 primers (second tier for the GP5/GP6-negative samples) detected additional 15%-25% HPV-positive samples compared with each pair used separately. Direct sequencing was then used to type the HPV. A readout of a sequence as short as 34 nucleotides within a specific region in the L1 gene is sufficient to type known or novel sequences. Because of its high sensitivity and cost-effectiveness, the two-tier PCR-DS was adopted by the authors as the current method of choice for HPV diagnosis with ultimate sequence precision.

Genomic diversity and evolution of papillomaviruses in rhesus monkeys

We are studying the diversity of and relationships among papillomaviruses (PVs) to understand the modes and timescales of PV evolution and in the hope of finding animal PVs that may serve as model systems for disease caused by human PVs (HPVs). Toward this goal, we have examined 326 genital samples from rhesus monkeys and long-tailed macaques with a PCR protocol optimized for detecting genital HPV types. In 28 of the rhesus monkey samples, we found amplicons derived from 12 different and novel PV genomes, RhPV-a to RhPV-m, with the likely taxonomic status of "type." The frequency with which novel RhPVs were detected suggests that rhesus monkeys may play host to PVs with a diversity similar to that of humans. In phylogenetic trees, all 12 of the different RhPVs and the previously described type RhPV-1 were members of the genital HPV supergroup and formed three minor branches distinct from the 11 branches formed by genital HPVs. We also identified a novel PV amplicon, MfPV-a, from a long-tailed macaque, a species belonging to the same genus as rhesus monkeys. MfPV-a turned out to be a close relative of five RhPVs. It appears that the evolution of primate lineages leading to the genus Macaca and to humans created transmission barriers for PVs, resulting in viral evolution closely linked to the host. Additional support for the linked-evolution hypothesis comes from considering the phylogenetic association of two other ape and monkey PVs with the genital HPVs, the supergroup formed by at least seven ungulate PVs, and the isolated phylogenetic position of the only known bird PV.

Genital papillomaviruses (PVs) and epidermodysplasia verruciformis PVs occur in the same monkey species: implications for PV evolution

Portions of the genome from two different papillomaviruses (PVs) of the Abyssinian Colobus monkey were sequenced and phylogenetically analyzed. This revealed that the major evolutionary separation between genital PVs and epidermodysplasia verruciformis-associated PVs (EV-PVs) hitherto found only in human papillomaviruses (HPVs) also exists in animal PVs. The sequence of the long control region (LCR) of Colobus monkey PV type 2 (CgPV-2) reveals a small size and an arrangement of potential cis-responsive elements typical of the EV-HPVs; namely four binding sites for the viral E2 protein, with one of them being located within the L1 gene, a cluster of nuclear factor I (NFI)- and AP-1-binding sites and a 50-bp sequence upstream of the E6 gene consisting only of the nucleotides A and T. This level of conservation of functional elements within the highly variable LCR suggests that CgPV-2 could be adopted as a model for studying human skin cancer associated with EV-HPVs. Although isolated from the same monkey species, the other Colobus monkey PV, CgPV-1, is a typical genital PV as shown by E1 and L1 sequence comparisons. The presence of these two major phylogenetic divisions of PVs in both human and monkey hosts strongly suggests that this diversification predated the evolutionary split between monkeys and apes. In other words, at least two different groups of PVs have been evolving separately in their respective primate hosts for more than 22 million years with only moderate sequence changes since their genesis.