Human papillomavirus 45 genetic variation and cervical cancer risk worldwide

Global evaluation of lineage-specific human papillomavirus capsid antigenicity using antibodies elicited by natural infection

Human Papillomavirus (HPV) type variants have been classified into lineages and sublineages based upon their whole genome sequence. Here we have examined the specificity of antibodies generated following natural infection with lineage variants of oncogenic types (HPV16, 18, 31, 33, 45, 52 and 58) by testing serum samples assembled from existing archives from women residing in Africa, The Americas, Asia or Europe against representative lineage-specific pseudoviruses for each genotype. We have subjected the resulting neutralizing antibody data to antigenic clustering methods and created relational antigenic profiles for each genotype to inform the delineation of lineage-specific serotypes. For most genotypes, there was evidence of differential recognition of lineage-specific antigens and in some cases of a sufficient magnitude to suggest that some lineages should be considered antigenically distinct within their respective genotypes. These data provide compelling evidence for a degree of lineage specificity within the humoral immune response following natural infection with oncogenic HPV.

In silico analysis of HLA-1 and HLA-2 recognition of a designed recombinant human papillomavirus vaccine based on L1 protein HPV subtype 45

BACKGROUND

Human leukocyte antigen (HLA) can bind and present the processed antigenic peptide derived from the vaccine to the T cell receptor, and this capability is crucial in determining the effectivity of the vaccine to terminate virus-infected cells, activate macrophages, and induce B cells to produce antibodies. A recombinant vaccine candidate based on protein L1 HPV45 was designed and analysed whether it is recognisable by T cells through the binding of their epitopes to HLAs.

METHODS

The study consisted of two parts: part one was the analysis of the L1 recombinant protein binding to HLA-1 and 2 epitopes, whereas part two was the distribution analysis of HPV-linked HLA allele. HLA allele sets found at high frequency in the general population and in specific Indonesian population were listed for the binding analysis of the recombinant L1 HPV45 protein. In part one, immunoepitope servers from IEDB were used to predict the binding of the designed proteins to HLA alleles. The prediction method for MHC-I binding prediction was the NetMHCpan EL 4.1 whilst for MHC-II binding prediction was the Consensus approach. Antigenicity analysis for each peptide was conducted using VaxiJen 2.0 with the threshold 1.0 to select the highly antigenic peptides, and positions of these epitopes in the secondary and tertiary structure of the recombinant protein were also predicted. The percent population coverage of the alleles capable of binding to these epitopes worldwide was also estimated. In part two, the worldwide distribution and frequency of HPV-related HLA-1 and 2 were studied.

RESULT

Two highly antigenic peptides (EEYDLQFIF and KLKFWTVDLK) were recognised by high-frequency HLA-1 alleles in both, the general and Western Javanese. In addition to these two epitopes, a few more peptides are also recognised by the high-frequency Western Javanese HLA-1 alleles, which are not in Weiskopf's list of high-frequency HLA-1 alleles in the general population. Analysis of the highly antigenic epitopes binding to HLA-DRB1 alleles in general (YIKGTSANM) and Western Javanese (LRRRPTIGP) populations showed that these peptide cores associate to HLA-DRB1*04, albeit the different sub-types, due to the presence of different allele in each population group. Analysis of the epitopes and the positive binding alleles showed on average 25.65% population coverage.

CONCLUSION

The recombinant vaccine candidate based on protein L1 HPV45 is presumed to contain highly antigenic peptides that can bind to high-frequency HLA-1 and 2 alleles present in general and Western Javanese populations. It was expected that the protein is capable of eliciting T cell-mediated responses in both populations; however, in vitro study is needed to prove the protectiveness of the designed recombinant protein.

Mechanical profile of human keratinocytes expressing HPV-18 oncogenes

During tumorigenesis, the mechanical properties of cancer cells change markedly, with decreased stiffness often accompanying a more invasive phenotype. Less is known about the changes in mechanical parameters at intermediate stages in the process of malignant transformation. We have recently developed a pre-tumoral cell model by stably transducing the immortalized but non-tumorigenic human keratinocyte cell line HaCaT with the E5, E6 and E7 oncogenes from HPV-18, one of the leading causes of cervical cancer and other types of cancer worldwide. We have used atomic force microscopy (AFM) to measure cell stiffness and to obtain mechanical maps of parental HaCaT and HaCaT E5/E6/E7-18 cell lines. We observed a significant decrease in Young's modulus in HaCaT E5/E6/E7-18 cells measured by nanoindentation in the central region, as well as decreased cell rigidity in regions of cell-cell contact measured by Peakforce Quantitative Nanomechanical Mapping (PF-QNM). As a morphological correlate, HaCaT E5/E6/E7-18 cells displayed a significantly rounder cell shape than parental HaCaT cells. Our results therefore show that decreased stiffness with concomitant perturbations in cell shape are early mechanical and morphological changes during the process of malignant transformation.

Genomic Risk Factors for Cervical Cancer

Cervical cancer is the fourth common cancer amongst women worldwide. Infection by high-risk human papilloma virus is necessary in most cases, but not sufficient to develop invasive cervical cancer. Despite a predicted genetic heritability in the range of other gynaecological cancers, only few genomic susceptibility loci have been identified thus far. Various case-control association studies have found corroborative evidence for several independent risk variants at the 6p21.3 locus (HLA), while many reports of associations with variants outside the HLA region remain to be validated in other cohorts. Here, we review cervical cancer susceptibility variants arising from recent genome-wide association studies and meta-analysis in large cohorts and propose 2q14 (PAX8), 17q12 (GSDMB), and 5p15.33 (CLPTM1L) as consistently replicated non-HLA cervical cancer susceptibility loci. We further discuss the available evidence for these loci, knowledge gaps, future perspectives, and the potential impact of these findings on precision medicine strategies to combat cervical cancer.

Lineage analysis of human papillomavirus types 31 and 45 in cervical samples of Iranian women

Knowing the regional lineages/sublineages of human papillomavirus 31 (HPV 31) and 45 would be of great importance for further evolutionary, epidemiological, and biological analysis. In this regard, to characterize more common lineages and sublineages of HPV 31 and 45, the sequence variations of E6 gene were investigated in normal, premalignant, and malignant samples collected from the cervix in Iran. In total, 54 HPV 31- and 24 HPV 45-positive samples were analyzed by hemi-nested polymerase chain reaction (PCR) and nested-PCR, respectively. All PCR products were subjected to direct sequencing analysis. The results indicated that all three lineages A, B, and C were detected in HPV 31-positive samples; among which HPV 31 lineage A was dominant as it was found in 66.7% of all samples. HPV 31 lineages B and C were identified in 5.5% and 27.8% of samples, respectively. In HPV 45-infected samples, lineage B comprised of 62.5% of all samples and the remaining 37.5%  belonged to lineage A. In conclusion, our findings showed that lineage A of HPV 31 was predominant in Iran. Lineage B of HPV 45 was also dominant among Iranian women. However, further studies with larger sample size should be addressed to estimate the pathogenicity risk of HPV 31 or HPV 45 lineages/sublineages in the development of cervical cancer among Iranian women.

Epidemiology and Burden of Human Papillomavirus and Related Diseases, Molecular Pathogenesis, and Vaccine Evaluation

Diagnosed in more than 90% of cervical cancers, the fourth deadliest cancer in women, human papillomavirus (HPV) is currently the most common pathogen responsible for female cancers. Moreover, HPV infection is associated with many other diseases, including cutaneous and anogenital warts, and genital and upper aerodigestive tract cancers. The incidence and prevalence of these pathologies vary considerably depending on factors including HPV genotype, regional conditions, the study population, and the anatomical site sampled. Recently, features of the cervicovaginal microbiota are found to be associated with the incidence of HPV-related diseases, presenting a novel approach to identify high-risk women through both blood and cervical samples. Overall, the HPV repartition data show that HPV infection and related diseases are more prevalent in developing countries. Moreover, the available (2-, 4-, and 9-valent) vaccines based on virus-like particles, despite their proven effectiveness and safety, present some limitations in terms of system development cost, transport cold chain, and oncogenic HPV variants. In addition, vaccination programs face some challenges, leading to a considerable burden of HPV infection and related diseases. Therefore, even though the new (9-valent) vaccine seems promising, next-generation vaccines as well as awareness programs associated with HPV vaccination and budget reinforcements for immunization are needed.

High-Risk Human Papillomavirus Identification in Precancerous Cervical Intraepithelial Lesions

OBJECTIVE

This review aims to summarize the currently available human papillomavirus (HPV) testing methods for precancerous cervical intraepithelial lesions.

MATERIALS AND METHODS

A literature search of PubMed using key words "high-risk HPV, precancerous cervical intraepithelial lesions, FDA-approved HPV tests, p16 IHC, Ki 67 IHC, fluorescent in situ hybridization for HPV, Pap smear, HPV vaccines, HPV tests using self-collected samples, and next-generation sequencing" was performed between January 1 and June 14, 2019. The package inserts of the Food and Drug Administration-approved HPV tests were obtained from the companies' Web sites.

RESULTS

Multiple morphology-based, immunohistochemical staining and nucleic acid HPV tests were reviewed, including the material required, methodologies, result interpretations, as well as their advantages, limitations, and futures. The structure of HPV and its natural history of infection and transmission were touched on as well for a better understanding of these testing methods.

CONCLUSIONS

Human papillomavirus tests are a critical component for cervical cancer screening, and understanding of these tests helps test results interpretation and patients' triage.

Human Papillomavirus Selected Properties and Related Cervical Cancer Prevention Issues

High-risk human papillomavirus strains are widely known to be the causative agents responsible for cervical cancer development. Aggregated damage caused by papillomaviruses solely is estimated in at least 5% of all malignancies of the human body and 16% in cancers that affect the female genital area. Enhanced understanding of the complex issue on how the high extent of carcinogenicity is eventually formed due to the infection by the Papoviridae family would contribute to enhancing current prevention strategies not only towards cervical cancer, but also other HPV associated cancers. This review article is aimed at presenting the key points in two directions: the current cervical cancer prevention and related aspects of HPV behavior. Virtually all applied technologies related to HPV diagnostics and screening programs, such as HPV tests, colposcopy-based tests (VIA/VILI), conventional and liquid-based cytology, currently available are presented. Issues of availability, advantages, and drawbacks of the screening programs, as well as vaccination strategies, are also reviewed in the article based on the analyzed sources. The current point of view regarding HPV is discussed with emphasis on the most problematic aspect of the HPV family concerning the observed increasing number of highly carcinogenic types. Present trends in HPV infection diagnostics throughout the human fluids and tissues are also reported, including the latest novelties in this field, such as HPV assay/self-sample device combinations. Besides, a brief outline of the related prevention issues in Kazakhstan, the leading country of Central Asia, is presented. Kazakhstan, as one of the post-soviet middle-income countries, may serve as an example of the current situation in those terrains, concerning the implementation of globally accepted cervical cancer prevention strategies. Along with positive achievements, such as the development of a nationwide screening program, a range of drawbacks is also analyzed and discussed.

Comprehensive Assessment of the Antigenic Impact of Human Papillomavirus Lineage Variation on Recognition by Neutralizing Monoclonal Antibodies Raised against Lineage A Major Capsid Proteins of Vaccine-Related Genotypes

Human papillomavirus (HPV) is the causative agent of cervical and other epithelial cancers. Naturally occurring variants of HPV have been classified into lineages and sublineages based on their whole-genome sequences, but little is known about the impact of this diversity on the structure and function of viral gene products. The HPV capsid is an icosahedral lattice comprising 72 pentamers of the major capsid protein (L1) and the associated minor capsid protein (L2). We investigated the potential impact of this genome variation on the capsid antigenicity of lineage and sublineage variants of seven vaccine-relevant, oncogenic HPV genotypes by using a large panel of monoclonal antibodies (MAbs) raised against the L1 proteins of lineage A antigens. Each genotype had at least one variant that displayed a ≥4-fold reduced neutralizing antibody sensitivity against at least one MAb, demonstrating that naturally occurring variation can affect one or more functional antigenic determinants on the HPV capsid. For HPV16, HPV18, HPV31, and HPV45, the overall impact was of a low magnitude. For HPV33 (sublineages A2 and A3 and lineages B and C), HPV52 (lineage D), and HPV58 (lineage C), however, variant residues in the indicated lineages and sublineages reduced their sensitivity to neutralization by all MAbs by up to 1,000-fold, suggesting the presence of key antigenic determinants on the surface of these capsids. These determinants were resolved further by site-directed mutagenesis. These data improve our understanding of the impact of naturally occurring variation on the antigenicity of the HPV capsid of vaccine-relevant oncogenic HPV genotypes.IMPORTANCE Human papillomavirus (HPV) is the causative agent of cervical and some other epithelial cancers. HPV vaccines generate functional (neutralizing) antibodies that target the virus particles (or capsids) of the most common HPV cancer-causing genotypes. Each genotype comprises variant forms that have arisen over millennia and which include changes within the capsid proteins. In this study, we explored the potential for these naturally occurring variant capsids to impact recognition by neutralizing monoclonal antibodies. All genotypes included at least one variant form that exhibited reduced recognition by at least one antibody, with some genotypes affected more than others. These data highlight the impact of naturally occurring variation on the structure of the HPV capsid proteins of vaccine-relevant oncogenic HPV genotypes.

Phylogeny and In Silico Structure Analysis of Major Capsid Protein (L1) Human Papillomavirus 45 from Indonesian Isolates

BACKGROUND

Human papillomavirus (HPV)-45 genotype circulates in high percentage in Bandung area - Indonesia, after HPV-16 and HPV-18. The aim of this study was to analyse variations of major capsid (L1) HPV-45 and its phylogeny. Furthermore in silico protein structure and epitope prediction was explored.

METHODS

L1 gene of HPV-45 was amplified, sequenced and aligned. Phylogenetic tree had been built and compared with a complete L1 HPV-45 sequence. Structure and epitope prediction of L1 protein were then developed in silico.

RESULTS

Of 5 L1 HPV-45 sequences collected, we have detected one variant of sub lineage A2 which was considered as a new variant, and two variants of B2. Superimposition of structure of these two variants with reference showed very similar structure. Furthermore, seven amino acid substitutions were found within these L1 variants of which two substitutions might change the polarity of corresponding amino acid I329T and S383G. The S383G occurred in surface loop (HI-Loop) of new L1 HPV-45 variant.

CONCLUSION

Similar structure of Indonesian variants indicates that amino acids variations do not affect the L1 structure. However, one substitution with altered amino acid polarity found within the area of surface loop suggests a potential impact in antibody recognition and neutralization.

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.

Self-Collected Specimens Revealed a Higher Vaccine- and Non-Vaccine-Type Human Papillomavirus Prevalences in a Cross-Sectional Study in Akuse

Background

Population-specific epidemiologic data on human Papillomavirus infection, which are limited in most of the SubSaharan African countries, are necessary for effective cervical cancer prevention. This study aimed to generate population-specific data on human Papillomavirus infections, and determine which of these, self-collected and provider-collected specimens, gives a higher estimate of the prevalence of human Papillomaviruses, including vaccine and non-vaccine-type human Papillomavirus.

Methods

In this cross-sectional study, following a questionnaire-based collection of epidemiological data, self-, and provider-collected specimens, obtained from women 15−65 years of age, were analysed for human Papillomavirus types by a nested-multiplex polymerase chain reaction, and for cervical lesions by Pap testing. HPV data were categorised according to risk type and vaccine types for further analysis.

Results

The difference between the overall human Papillomavirus infection prevalences obtained with the self-collected specimens, 43.1% (95% CI of 38.0–51.0%) and that with the provider-collected samples, 23.3% (95% CI of 19.0–31.0%) were significant (p ≤ 0.001). The prevalence of quadrivalent vaccine-type human Papillomaviruses was 12.3% with self-collected specimens, but 6.0% with provider-collected specimens. For the nonavalent vaccine-types, the prevalences were 26.6% and 16.7% respectively. There were multiple infections involving both vaccine-preventable and nonvaccine preventable high-risk human Papillomavirus genotypes.

Conclusion

The Akuse subdistrict can, therefore, be said to have a high burden of human Papillomavirus infections, which included nonvaccine types, as detected with both self-collected and provider-collected specimens. These imply that self-collection is to be given a higher consideration as a means for a population-based high-risk human Papillomavirus infections burdens assessment/screening. Additionally, even with a successful implementation of the HPV vaccination, if introduced in Ghana, there is still the need to continue with the screening of women.

Mucosal and Cutaneous Human Papillomavirus Infections and Cancer Biology

Papillomaviridae is a family of small non-enveloped icosahedral viruses with double-stranded circular DNA. More than 200 different human papillomaviruses (HPVs) have been listed so far. Based on epidemiological data, a subgroup of alphapapillomaviruses (alpha HPVs) was referred to as high-risk (HR) HPV types. HR HPVs are the etiological agents of anogenital cancer and a subset of head and neck cancers. The cutaneous HPV types, mainly from beta and gamma genera, are widely present on the surface of the skin in the general population. However, there is growing evidence of an etiological role of betapapillomaviruses (beta HPVs) in non-melanoma skin cancer (NMSC), together with ultraviolet (UV) radiation. Studies performed on mucosal HR HPV types, such as 16 and 18, showed that both oncoproteins E6 and E7 play a key role in cervical cancer by altering pathways involved in the host immune response to establish a persistent infection and by promoting cellular transformation. Continuous expression of E6 and E7 of mucosal HR HPV types is essential to initiate and to maintain the cellular transformation process, whereas expression of E6 and E7 of cutaneous HPV types is not required for the maintenance of the skin cancer phenotype. Beta HPV types appear to play a role in the initiation of skin carcinogenesis, by exacerbating the accumulation of UV radiation-induced DNA breaks and somatic mutations (the hit-and-run mechanism), and they would therefore act as facilitators rather than direct actors in NMSC. In this review, the natural history of HPV infection and the transforming properties of various HPV genera will be described, with a particular focus on describing the state of knowledge about the role of cutaneous HPV types in NMSC.

Genetic diversity of human papillomavirus types 35, 45 and 58 in cervical cancer in Brazil

In Brazil, most studies of intra-type variants of human papillomavirus (HPV) have focused on HPV16 and HPV18, but other high-risk HPV types have not been studied. Here, we report the prevalence of lineages and variants of HPV35, HPV45 and HPV58 in cervical cancers from the Amazonian and Southeast Brazilian regions. The most frequent sublineages were A1 for HPV35, B2 for HPV45, and A2 for HPV58. The Southeast region had a higher frequency of the B2 sublineage of HPV45, and for HPV35, the genetic and nucleotide sequence diversity were higher in the Southeast region, suggesting that regional factors are influencing the diversity and lineage prevalence.

Unique LCR variations among lineages of HPV16, 18 and 45 isolates from women with normal cervical cytology in Ghana

Background

In addition to being useful for classification, sequence variations of human Papillomavirus (HPV) genotypes have been implicated in differential oncogenic potential and a differential association with the different histological forms of invasive cervical cancer. These associations have also been indicated for HPV genotype lineages and sub-lineages. In order to better understand the potential implications of lineage variation in the occurrence of cervical cancers in Ghana, we studied the lineages of the three most prevalent HPV genotypes among women with normal cytology as baseline to further studies.

Methods

Of previously collected self- and health personnel-collected cervical specimen, 54, which were positive for HPV16, 18 and 45, were selected and the long control region (LCR) of each HPV genotype was separately amplified by a nested PCR. DNA sequences of 41 isolates obtained with the forward and reverse primers by Sanger sequencing were analysed.

Results

Nucleotide sequence variations of the HPV16 genotypes were observed at 30 positions within the LCR (7460 – 7840). Of these, 19 were the known variations for the lineages B and C (African lineages), while the other 11 positions had variations unique to the HPV16 isolates of this study. For the HPV18 isolates, the variations were at 35 positions, 22 of which were known variations of Africa lineages and the other 13 were unique variations observed for the isolates obtained in this study (at positions 7799 and 7813). HPV45 isolates had variations at 35 positions and 2 (positions 7114 and 97) were unique to the isolates of this study.

Conclusion

This study provides the first data on the lineages of HPV 16, 18 and 45 isolates from Ghana. Although the study did not obtain full genome sequence data for a comprehensive comparison with known lineages, these genotypes were predominately of the Africa lineages and had some unique sequence variations at positions that suggest potential oncogenic implications. These data will be useful for comparison with lineages of these genotypes from women with cervical lesion and all the forms of invasive cervical cancers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-017-0755-z) contains supplementary material, which is available to authorized users.

Identification of novel human papillomavirus lineages and sublineages in HIV/HPV-coinfected pregnant women by next-generation sequencing

Infection by human papillomavirus (HPV) is a necessary condition for development of cervical cancer, and has also been associated with malignancies of other body anatomical sites. Specific HPV types have been associated with premalignant lesions and invasive carcinoma, but mounting evidence suggests that within-type lineages and sublineages also display distinct biological characteristics associated with persistent infections and evolution to cervical cancer. In the present study, we have assessed HPV multiple infection and variation from a cohort of highly susceptible, HIV(+) pregnant women using next-generation sequencing and an in-house pipeline for HPV full-length genome assembly. Seventy-two consensus sequences representing complete or near-complete (>97%) HPV genomes were assembled, spanning 28 different types. Genetic distance and phylogenetic analyses allowed us to propose the classification of novel HPV lineages and sublineages across nine HPV types, including two high-risk types. HPV diversity may be a hallmark of immunosuppressed patients upon HIV infection and AIDS progression.

Characterization of Intra-Type Variants of Oncogenic Human Papillomaviruses by Next-Generation Deep Sequencing of the E6/E7 Region

Different human papillomavirus (HPV) types are characterized by differences in tissue tropism and ability to promote cell proliferation and transformation. In addition, clinical and experimental studies have shown that some genetic variants/lineages of high-risk HPV (HR-HPV) types are characterized by increased oncogenic activity and probability to induce cancer. In this study, we designed and validated a new method based on multiplex PCR-deep sequencing of the E6/E7 region of HR-HPV types to characterize HPV intra-type variants in clinical specimens. Validation experiments demonstrated that this method allowed reliable identification of the different lineages of oncogenic HPV types. Advantages of this method over other published methods were represented by its ability to detect variants of all HR-HPV types in a single reaction, to detect variants of HR-HPV types in clinical specimens with multiple infections, and, being based on sequencing of the full E6/E7 region, to detect amino acid changes in these oncogenes potentially associated with increased transforming activity.

Genetic diversity of HPV16 and HPV18 in Brazilian patients with invasive cervical cancer

Cervical cancer is the fourth most common cancer among women, and ∼70-80% of these cancers are associated with two human papillomavirus types: HPV16 and HPV18. Several studies have reported that intra-type diversity is associated with the progression of infection to invasive cancer. Herein, we report the genetic diversity of HPV16 and HPV18 in a cohort of 594 Brazilian women with invasive cervical cancer and describe the prevalence of lineages and intra-type diversity prior to the implementation of the public immunization program in Brazil. HPV detection and genotyping were performed using PCR, PGMY/GP primers, and DNA extracted from fresh tumors. The HPV16 (378 women) and HPV18 (80 women) lineages were identified by PCR and sequencing of the LCR and E6 fragments, followed by SNV comparison and phylogenetic analysis. In our cohort, was found a higher frequency of the lineage A (in 217 women), followed by lineage D (in 97 women) and lineages B and C (in 10 women each) for HPV16; and a higher frequency of lineage A (in 56 women) followed by lineage B (in 15 women) in HPV18. The genetic diversity of HPV16 indicated a recent expansion of specific variants or a selective advantage that is associated with invasive cancer; this pattern was not observed for HPV18.

Naturally Occurring Major and Minor Capsid Protein Variants of Human Papillomavirus 45 (HPV45): Differential Recognition by Cross-Neutralizing Antibodies Generated by HPV Vaccines

We investigated naturally occurring variation within the major (L1) and minor (L2) capsid proteins of human papillomavirus genotype 45 (HPV45). Pseudoviruses (PsVs) representing HPV45 sublineages A1, A2, A3, B1, and B2 exhibited comparable particle-to-infectivity ratios and morphologies but demonstrated both increased (A2, A3, and B1) and decreased (B2) sensitivities to cross-neutralization by HPV vaccine antibodies compared to that of the A1 sublineage. Mutant PsVs identified HI loop residue 357 as being critical for conferring this differential sensitivity.

Human papillomavirus variants among Inuit women in northern Quebec, Canada

Background

Inuit communities in northern Quebec have high rates of human papillomavirus (HPV) infection, cervical cancer and cervical cancer–related mortality as compared to the Canadian population. HPV types can be further classified as intratypic variants based on the extent of homology in their nucleotide sequences. There is limited information on the distribution of intratypic variants in circumpolar areas.

Objective

Our goal was to describe the HPV intratypic variants and associated baseline characteristics.

Design

We collected cervical cell samples in 2002–2006 from 676 Inuit women between the ages of 15 and 69 years in Nunavik. DNA isolates from high-risk HPVs were sequenced to determine the intratypic variant.

Results

There were 149 women that were positive for HPVs 16, 18, 31, 33, 35, 45, 52, 56 or 58 during follow-up. There were 5 different HPV16 variants, all of European lineage, among the 57 women positive for this type. There were 8 different variants of HPV18 present and all were of European lineage (n=21). The majority of samples of HPV31 (n=52) were of lineage B. The number of isolates and diversity of the other HPV types was low. Age was the only covariate associated with HPV16 variant category.

Conclusions

These frequencies are similar to what was seen in another circumpolar region of Canada, although there appears to be less diversity as only European variants were detected. This study shows that most variants were clustered in one lineage for each HPV type.

Human Papillomavirus 18 Genetic Variation and Cervical Cancer Risk Worldwide

Human papillomavirus 18 (HPV18) is the second most carcinogenic HPV type, after HPV16, and it accounts for approximately 12% of squamous cell carcinoma (SCC) as well as 37% of adenocarcinoma (ADC) of the cervix worldwide. We aimed to evaluate the worldwide diversity and carcinogenicity of HPV18 genetic variants by sequencing the entire long control region (LCR) and the E6 open reading frame of 711 HPV18-positive cervical samples from 39 countries, taking advantage of the International Agency for Research on Cancer biobank. A total of 209 unique HPV18 sequence variants were identified that formed three phylogenetic lineages (A, B, and C). A and B lineages each divided into four sublineages, including a newly identified candidate B4 sublineage. The distribution of lineages varied by geographical region, with B and C lineages found principally in Africa. HPV18 (sub)lineages were compared between 453 cancer cases and 236 controls, as well as between 81 ADC and 160 matched SCC cases. In region-stratified analyses, there were no significant differences in the distribution of HPV18 variant lineages between cervical cancer cases and controls or between ADC and SCC. In conclusion, our findings do not support the role of HPV18 (sub)lineages for discriminating cancer risk or explaining why HPV18 is more strongly linked with ADC than SCC.

IMPORTANCE

This is the largest and most geographically/ethnically diverse study of the genetic variation of HPV18 to date, providing a comprehensive reference for phylogenetic classification of HPV18 sublineages for epidemiological and biological studies.

Lineage distribution and E2 sequence variation of high-risk human papillomavirus types isolated from patients with cervical cancer in Sichuan province, China

To explore the nucleotide sequence variability of the E2 gene in high-risk HPV types in cervical cancer patients from Sichuan province, China, the E2 genes of eight high-risk HPV types were amplified and sequenced. Several novel nucleotide substitutions and deletions were observed. The lineages to which the isolates belonged were determined by phylogenetic analysis, employing the sequence of the representative lineages/sublineages in the coherent classification and nomenclature system as references. This study updates the lineage distribution data on high-risk HPV types in Southwest China and helps broaden understanding of the polymorphism of the E2 gene.