Identification of a novel human gammapapillomavirus species

Case control study comparing the HPV genome in patients with oral cavity squamous cell carcinoma to normal patients using metagenomic shotgun sequencing

The aim of this study was to carry out a case control study comparing the HPV genome in patients with oral cavity squamous cell carcinoma (OC-SCC) to normal patients using metagenomic shotgun sequencing. We recruited 50 OC-SCC cases which were then matched with a control patient by age, gender, race, smoking status and alcohol status. DNA was extracted from oral wash samples from all patients and whole genome shotgun sequencing performed. The raw sequence data was cleaned, reads aligned with the human genome (GRCH38), nonhuman reads identified and then HPV genotypes identified using HPViewer. In the 50 patients with OC-SCC, the most common subsite was tongue in 26 (52%). All patients were treated with primary resection and neck dissection. All but 2 tumors were negative on p16 immunohistochemistry. There were no statistically significant differences between the cases and controls in terms of gender, age, race/ethnicity, alcohol drinking, and cigarette smoking. There was no statistically significant difference between the cancer samples and control samples in the nonhuman DNA reads (medians 4,228,072 vs. 5,719,715, P value = 0.324). HPV was detected in 5 cases (10%) of OC-SCC (genotypes 10, 16, 98) but only 1 tumor sample (genotype 16) yielded a high number of reads to suggest a role in the etiology of OC-SCC. HPV was detected in 4 control patients (genotypes 16, 22, 76, 200) but all had only 1–2 HPV reads per human genome. Genotypes of HPV are rarely found in patients with oral cancer.

Emerging biomarkers and clinical significance of HPV genotyping in prevention and management of cervical cancer

Cervical cancer is a growing and serious problem world-wide in women, but more acute in developing countries especially in Indian subcontinent. The main causative agent for the disease is Human Papilloma Virus (HPV). The history of the cervical cancer goes back to eighteenth century as the HPV infection is reported since 1800s. Presently, the genetic structure of HPV is well defined. Several screening tests including cytology and visual based screening and high risk HPV testing are available. Also available are various clinical and commercial diagnostic tests. However due to the lack of awareness and population-based screening programs, the morbidity and mortality rate is alarmingly high. There are new emerging biomarkers including E6/E7 mRNA, p16^ink4a, markers of aberrant S-phase induction, chromosomal abnormalities and miRNAs along with advanced genotyping methods. These markers have clinical significance and are helpful in disease prevention and management. Further, recent advancement in the field of metagenomics has increased the prospects of identifying newer microbes, viruses hitherto reported thus far in the context of HPV infection. Analysis of HPV cases using modern tools including genotyping using more powerful biomarkers is envisaged to enhance the prospects of early diagnosis, better prognosis, more reliable treatment and eventual management of the disease.

Human Viruses: Emergence and Evolution

Many new viruses have emerged in the last five decades. These newer genetically active agents have a major impact on the public health systems worldwide. Most emerging infections appear to be caused by pathogens already present in the environment, brought out of obscurity or given a selective advantage by changing conditions and afforded an opportunity to infect new host populations. Also on rare occasions, a new variant may evolve and cause a new disease. Altered virus transmission because of deforestation and environment change, ecological changes and agricultural development, commerce, technology, microbial adaptation and change, breakdown of public health measures, and deficiencies in public health infrastructure are the reasons for emergence and reemergence of infectious diseases in general and viral infections in particular.

Specific factors precipitating disease emergence can be identified in virtually all cases. Moreover, these factors are increasing in prevalence. This increase, together with the ongoing evolution of viral and microbial variants and selection for drug resistance, suggests that infections will continue to emerge and probably increase and emphasize the urgent need for effective surveillance and control. These viruses are rich source of emerging diseases due to the introduction of infections from other species in the zoonotic pool. In the near future, there is an urgent need to monitor collaboration between human–animal interface so that public health risks can be understood. A number of activities increase microbial traffic from animals to humans or disseminate microbes from isolated groups into new populations and as a result promote emergence and epidemics. In some cases, including many of the most novel infections, the agents are zoonotic crossing from their natural hosts into the human population because of many similarities. Vector-borne diseases also have a natural advantage of dissemination.

Discovery, characterisation and genomic variation of six novel Gammapapillomavirus types from penile swabs in South Africa

Six novel human papillomaviruses from penile swabs were characterised. Multiple full genome clones for each novel type were generated, and complete genome sizes were: HPV211 (7253bp), HPV212 (7208bp), HPV213 (7096bp), HPV214 (7357), HPV215 (7186bp) and HPV216 (7233bp). Phylogenetically the novel papillomaviruses all clustered with Gammapapillomaviruses: HPV211 is most closely related to HPV168 (72% identity in the L1 nucleotide sequence) of the Gamma-8 species, HPV212 is most closely related to HPV144 (82.9%) of the Gamma-17 species, HPV213 is most closely related to HPV153 (71.8%) of the Gamma-13 species, HPV214 is most closely related to HPV103 (75.3%) of the Gamma-6 species, HPV215 and HPV216 are most closely related to HPV129 (76.8% and 79.2% respectively) of the Gamma-9 species. The novel HPV types demonstrated the classical genomic organisation of Gammapapillomavirusess, with seven open reading frames (ORFs) encoding five early (E1, E2, E4, E6 and E7) and two late (L1 and L2) proteins. Typical of Gammapapillomavirusess the novel types all lacked the E5 ORF and HPV214 also lacked the E6 ORF. HPV212 had nine unique variants, HPV213 had five and HPV215 had four variants. Conserved domains observed among the novel types are the Zinc finger Binding Domain and PDZ domains. A retinoblastoma binding domain (pRB) binding domain in E7 protein was additionally identified in HPV214. This study expands the knowledge of the rapidly growing Gammapapillomavirus genus.

Laboratory Methods in Molecular Epidemiology: Viral Infections

Viruses, which are the most abundant biological entities on the planet, have been regarded as the "dark matter" of biology in the sense that despite their ubiquity and frequent presence in large numbers, their detection and analysis are not always straightforward. The majority of them are very small (falling under the limit of 0.5 μm), and collectively, they are extraordinarily diverse. In fact, the majority of the genetic diversity on the planet is found in the so-called virosphere, or the world of viruses. Furthermore, the most frequent viral agents of disease in humans display an RNA genome, and frequently evolve very fast, due to the fact that most of their polymerases are devoid of proofreading activity. Therefore, their detection, genetic characterization, and epidemiological surveillance are rather challenging. This review (part of the Curated Collection on Advances in Molecular Epidemiology of Infectious Diseases) describes many of the methods that, throughout the last few decades, have been used for viral detection and analysis. Despite the challenge of having to deal with high genetic diversity, the majority of these methods still depend on the amplification of viral genomic sequences, using sequence-specific or sequence-independent approaches, exploring thermal profiles or a single nucleic acid amplification temperature. Furthermore, viral populations, and especially those with RNA genomes, are not usually genetically uniform but encompass swarms of genetically related, though distinct, viral genomes known as viral quasispecies. Therefore, sequence analysis of viral amplicons needs to take this fact into consideration, as it constitutes a potential analytic problem. Possible technical approaches to deal with it are also described here. *This article is part of a curated collection.

Quito's virome: Metagenomic analysis of viral diversity in urban streams of Ecuador's capital city

In Quito, the microbiological contamination of surface water represents a public health problem, mainly due to the lack of sewage treatment from urban wastewater. Contaminated water contributes to the transmission of many enteric pathogens through direct consumption, agricultural and recreational use. Among the different pathogens present in urban discharges, viruses play an important role on disease, being causes of gastroenteritis, hepatitis, meningitis, respiratory infections, among others. This study analyzes the presence of viruses in highly impacted surface waters of urban rivers using next-generation sequencing techniques. Three representative locations of urban rivers, receiving the main discharges from Quito sewerage system, were selected. Water samples of 500 mL were concentrated by skimmed-milk flocculation method and the viral nucleic acid was extracted and processed for high throughput sequencing using Illumina MiSeq. The results yielded very relevant data of circulating viruses in the capital of Ecuador. A total of 29 viral families were obtained, of which 26 species were associated with infections in humans. Among the 26 species identified, several were related to gastroenteritis: Human Mastadenovirus F, Bufavirus, Sapporovirus, Norwalk virus and Mamastrovirus 1. Also detected were: Gammapapillomavirus associated with skin infections, Polyomavirus 1 related to cases of kidney damage, Parechovirus A described as cause of neonatal sepsis with neurological affectations and Hepatovirus A, the etiologic agent of Hepatitis A. Other emergent viruses identified, of which its pathogenicity remains to be fully clarified, were: Bocavirus, Circovirus, Aichi Virus and Cosavirus. The wide diversity of species detected through metagenomics gives us key information about the public health risks present in the urban rivers of Quito. In addition, this study describes for the first time the presence of important infectious agents not previously reported in Ecuador and with very little reports in Latin America.

Utility of high-throughput DNA sequencing in the study of the human papillomaviruses

The Papillomaviridae family is probably the most diverse group of viruses that affect vertebrates. The study of the relationship between infection by certain types of human papillomavirus (HPV) and the development of neoplastic epithelial lesions is of particular interest because of the high prevalence of HPV-related carcinomas in populations of developing countries. To understand the mechanisms of infection and their association with different clinical manifestations, molecular tools play an important role in the description of new types of HPV, the characterization of effector properties of the viral factors, the specific diagnosis and monitoring of HPV types, and the alteration patterns at genetic level in the host. Technological advances in the field of DNA sequencing have led to the development of different next-generation sequencing systems, allowing obtaining a large amount of data and broadening the applications to study viral diseases. In this review, we summarize the main approaches and their perspectives where the use of massively parallel sequencing has been proved as a useful tool in the research of the HPV infection.

Complete Genome Sequence of a Novel Human Gammapapillomavirus Isolated from Skin

A novel human papillomavirus (HPV ICB1) was fully characterized from a skin swab by using a sensitive degenerate PCR protocol combined with next-generation sequencing. The L1 open reading frame of HPV ICB1 shares 70.54% nucleotide homology with its closest relative, HPV164, and thus constitutes a novel human gammapapillomavirus.

Characterization of two novel gammapapillomaviruses, HPV179 and HPV184, isolated from common warts of a renal-transplant recipient

Gammapapillomavirus (Gamma-PV) is a diverse and rapidly expanding PV-genus, currently consisting of 76 fully characterized human papillomavirus (HPV) types. In this study, DNA genomes of two novel HPV types, HPV179 and HPV184, obtained from two distinct facial verrucae vulgares specimens of a 64 year-old renal-transplant recipient, were fully cloned, sequenced and characterized. HPV179 and HPV184 genomes comprise 7,228-bp and 7,324-bp, respectively, and contain four early (E1, E2, E6 and E7) and two late genes (L1 and L2); the non-coding region is typically positioned between L1 and E6 genes. Phylogenetic analysis of the L1 nucleotide sequence placed both novel types within the Gamma-PV genus: HPV179 was classified as a novel member of species Gamma-15, additionally containing HPV135 and HPV146, while HPV184 was classified as a single member of a novel species Gamma-25. HPV179 and HPV184 type-specific quantitative real-time PCRs were further developed and used in combination with human beta-globin gene quantitative real-time PCR to determine the prevalence and viral load of the novel types in the patient's facial warts and several follow-up skin specimens, and in a representative collection, a total of 569 samples, of HPV-associated benign and malignant neoplasms, hair follicles and anal and oral mucosa specimens obtained from immunocompetent individuals. HPV179 and HPV184 viral loads in patients' facial warts were estimated to be 2,463 and 3,200 genome copies per single cell, respectively, suggesting their active role in the development of common warts in organ-transplant recipients. In addition, in this particular patient, both novel types had established a persistent infection of the skin for more than four years. Among immunocompetent individuals, HPV179 was further detected in low-copy numbers in a few skin specimens, indicating its cutaneous tissue tropism, while HPV184 was further detected in low-copy numbers in one mucosal and a few skin specimens, suggesting its dual tissue tropism.

Frequency and distribution of simple and compound microsatellites in forty-eight Human papillomavirus (HPV) genomes

Simple sequence repeats (SSRs) are tandem-repeated sequences ubiquitously present but differentially distributed across genomes. Present study is a systematic analysis for incidence, composition and complexity of different microsatellites in 48 representative Human papillomavirus (HPV) genomes. The analysis revealed a total of 1868 SSRs and 120 cSSRs. However, four genomes (HPV-60, HPV-92, HPV-112 and HPV-136) lacked any cSSR content; while HPV-31 accounted for a maximum of 10 cSSRs. An overall increase in cSSR% with higher dMAX was observed. The SSRs and cSSRs were prevalent in coding regions. Poly(A/T) repeats were significantly more abundant than poly(G/C) repeats possibly due to high (A/T) content of the HPV genomes. Further, higher prevalence of di-nucleotide repeats over tri-nucleotide repeats may be attributed to instability of former because of higher slippage rate. An in-depth study of the satellite sequences would provide an insight into the imperfections and evolution of microsatellites.

Characterization of human papillomavirus type 154 and tissue tropism of gammapapillomaviruses

The novel human papillomavirus type 154 (HPV154) was characterized from a wart on the crena ani of a three-year-old boy. It was previously designated as the putative HPV type FADI3 by sequencing of a subgenomic FAP amplicon. We obtained the complete genome by combined methods including rolling circle amplification (RCA), genome walking through an adapted method for detection of integrated papillomavirus sequences by ligation-mediated PCR (DIPS-PCR), long-range PCR, and finally by cloning of four overlapping amplicons. Phylogenetically, the HPV154 genome clustered together with members of the proposed species Gammapapillomavirus 11, and demonstrated the highest identity in L1 to HPV136 (68.6%). The HPV154 was detected in 3% (2/62) of forehead skin swabs from healthy children. In addition, the different detection sites of 62 gammapapillomaviruses were summarized in order to analyze their tissue tropism. Several of these HPV types have been detected from multiple sources such as skin, oral, nasal, and genital sites, suggesting that the gammapapillomaviruses are generalists with a broader tissue tropism than previously appreciated. The study expands current knowledge concerning genetic diversity and tropism among HPV types in the rapidly growing gammapapillomavirus genus.

Human papillomavirus community in healthy persons, defined by metagenomics analysis of human microbiome project shotgun sequencing data sets

Human papillomavirus (HPV) causes a number of neoplastic diseases in humans. Here, we show a complex normal HPV community in a cohort of 103 healthy human subjects, by metagenomics analysis of the shotgun sequencing data generated from the NIH Human Microbiome Project. The overall HPV prevalence was 68.9% and was highest in the skin (61.3%), followed by the vagina (41.5%), mouth (30%), and gut (17.3%). Of the 109 HPV types as well as additional unclassified types detected, most were undetectable by the widely used commercial kits targeting the vaginal/cervical HPV types. These HPVs likely represent true HPV infections rather than transitory exposure because of strong organ tropism and persistence of the same HPV types in repeat samples. Coexistence of multiple HPV types was found in 48.1% of the HPV-positive samples. Networking between HPV types, cooccurrence or exclusion, was detected in vaginal and skin samples. Large contigs assembled from short HPV reads were obtained from several samples, confirming their genuine HPV origin. This first large-scale survey of HPV using a shotgun sequencing approach yielded a comprehensive map of HPV infections among different body sites of healthy human subjects.

IMPORTANCE

This nonbiased survey indicates that the HPV community in healthy humans is much more complex than previously defined by widely used kits that are target selective for only a few high- and low-risk HPV types for cervical cancer. The importance of nononcogenic viruses in a mixed HPV infection could be for stimulating or inhibiting a coexisting oncogenic virus via viral interference or immune cross-reaction. Knowledge gained from this study will be helpful to guide the designing of epidemiological and clinical studies in the future to determine the impact of nononcogenic HPV types on the outcome of HPV infections.

Cross-roads in the classification of papillomaviruses

Acceptance of an official classification for the family Papillomaviridae based purely on DNA sequence relatedness, was achieved as late as 2003. The rate of isolation and characterization of new papillomavirus types has greatly depended on and subjected to the development of new laboratory techniques. Introduction of every new technique led to a temporarily burst in the number of new isolates. In the following, the bumpy road towards achieving a classification system combined with the controversies of implementing and accepting new techniques will be summarized. An update of the classification of the 170 human papillomavirus (HPV) types presently known is presented. Arguments towards the implementation of metagenomic sequencing for this rapidly growing family will be presented.

Human viruses: discovery and emergence

There are 219 virus species that are known to be able to infect humans. The first of these to be discovered was yellow fever virus in 1901, and three to four new species are still being found every year. Extrapolation of the discovery curve suggests that there is still a substantial pool of undiscovered human virus species, although an apparent slow-down in the rate of discovery of species from different families may indicate bounds to the potential range of diversity. More than two-thirds of human viruses can also infect non-human hosts, mainly mammals, and sometimes birds. Many specialist human viruses also have mammalian or avian origins. Indeed, a substantial proportion of mammalian viruses may be capable of crossing the species barrier into humans, although only around half of these are capable of being transmitted by humans and around half again of transmitting well enough to cause major outbreaks. A few possible predictors of species jumps can be identified, including the use of phylogenetically conserved cell receptors. It seems almost inevitable that new human viruses will continue to emerge, mainly from other mammals and birds, for the foreseeable future. For this reason, an effective global surveillance system for novel viruses is needed.

Characterization of novel cutaneous human papillomavirus genotypes HPV-150 and HPV-151

DNA from two novel HPV genotypes, HPV-150 and HPV-151, isolated from hair follicles of immuno-competent individuals, was fully cloned, sequenced and characterized. The complete genomes of HPV-150 and HPV-151 are 7,436-bp and 7,386-bp in length, respectively. Both contain genes for at least six proteins, namely E6, E7, E1, E2, L2, L1, as well as a non-coding upstream regulatory region located between the L1 and E6 genes: spanning 416-bp in HPV-150 (genomic positions 7,371 to 350) and 322-bp in HPV-151 (genomic positions 7,213 to 148). HPV-150 and HPV-151 are phylogenetically placed within the Betapapillomavirus genus and are most closely related to HPV-96 and HPV-22, respectively. As in other members of this genus, the intergenic E2-L2 region is very short and does not encode for an E5 gene. Both genotypes contain typical zinc binding domains in their E6 and E7 proteins, but HPV-151 lacks the regular pRb-binding core sequence within its E7 protein. In order to assess the tissue predilection and clinical significance of the novel genotypes, quantitative type-specific real-time PCR assays were developed. The 95% detection limits of the HPV-150 and HPV-151 assays were 7.3 copies/reaction (range 5.6 to 11.4) and 3.4 copies/reaction (range 2.5 to 6.0), respectively. Testing of a representative collection of HPV-associated mucosal and cutaneous benign and malignant neoplasms and hair follicles (total of 540 samples) revealed that HPV-150 and HPV-151 are relatively rare genotypes with a cutaneous tropism. Both genotypes were found in sporadic cases of common warts and SCC and BCC of the skin as single or multiple infections usually with low viral loads. HPV-150 can establish persistent infection of hair follicles in immuno-competent individuals. A partial L1 sequence of a putative novel HPV genotype, related to HPV-150, was identified in a squamous cell carcinoma of the skin obtained from a 64-year old immuno-compromised male patient.

Metagenomics and the molecular identification of novel viruses

There have been rapid recent developments in establishing methods for identifying and characterising viruses associated with animal and human diseases. These methodologies, commonly based on hybridisation or PCR techniques, are combined with advanced sequencing techniques termed ‘next generation sequencing’. Allied advances in data analysis, including the use of computational transcriptome subtraction, have also impacted the field of viral pathogen discovery. This review details these molecular detection techniques, discusses their application in viral discovery, and provides an overview of some of the novel viruses discovered. The problems encountered in attributing disease causality to a newly identified virus are also considered.

Classification of papillomaviruses (PVs) based on 189 PV types and proposal of taxonomic amendments

We present an expansion of the classification of the family Papillomaviridae, which now contains 29 genera formed by 189 papillomavirus (PV) types isolated from humans (120 types), non-human mammals, birds and reptiles (64, 3 and 2 types, respectively). To accommodate the number of PV genera exceeding the Greek alphabet, the prefix "dyo" is used, continuing after the Omega-PVs with Dyodelta-PVs. The current set of human PVs is contained within five genera, whereas mammalian, avian and reptile PVs are contained within 20, 3 and 1 genera, respectively. We propose standardizations to the names of a number of animal PVs. As prerequisite for a coherent nomenclature of animal PVs, we propose founding a reference center for animal PVs. We discuss that based on emerging species concepts derived from genome sequences, PV types could be promoted to the taxonomic level of species, but we do not recommend implementing this change at the current time.