Human Papillomavirus E7 Oncoprotein Promotes Proliferation and Migration through the Transcription Factor E2F1 in Cervical Cancer Cells.

BACKGROUND: High-Risk Human Papillomavirus (HR-HPV) persistent infection is the main cause of cervical cancer and its precancerous lesions. A previous study showed that HPV16 and HPV58 infections were the most common infection types in the local region. Some studies also declared that HPV58 E7 variants increased the risk of cervical cancer among Asian populations. OBJECTIVE: This study aimed to determine whether the HPV58 E7 T20I (C632T) variant promotes the malignant behavior of cervical cancer cells and the underlying mechanism of the HR-HPV E7 oncoprotein involved in the development of cervical cancer. METHODS: CCK-8 and clone formation assays were used to detect cell proliferation ability. Transwell assays and cell wound healing assays were used to evaluate cell migration ability. Targeted knockdown of E2F1 expression using specific siRNA, RT-qPCR and Western blot were performed to assess gene expression changes. A chromatin immunoprecipitation assay was used to verify that E2F1 interacted with the TOP2A promoter region. RESULTS: HPV58 E7 and HPV58 E7M oncoproteins increased the proliferation and migration ability of cervical cancer cells. However, the HPV58 E7 T20I variant did not promote malignant behaviors compared with wildtype HPV58 E7. HPV E7 and E7M oncoproteins increased the expression of TOP2A, BIRC5 and E2F1, and knockdown of HPV E7 decreased their expression. Low E2F1 expression reduced the expression of TOP2A and BIRC5 and inhibited the proliferation and migration ability of cervical cancer cells. E2F1 interacted with the TOP2A gene promoter region to promote its transcriptional expression. CONCLUSION: The HPV58 E7 T20I variant did not promote malignant behaviors compared with wild-type HPV58 E7. The HR-HPV E7 oncoprotein enhanced the proliferation and migration of cervical cancer cells, which was considered to be due to the HPV E7 oncoprotein, increasing the expression of BIRC5 and TOP2A by upregulating the transcription factor E2F1.

Combined prophylactic and therapeutic immune responses against human papillomaviruses induced by a thioredoxin-based L2-E7 nanoparticle vaccine.

Global burden of cervical cancer, the most common cause of mortality caused by human papillomavirus (HPV), is expected to increase during the next decade, mainly because current alternatives for HPV vaccination and cervical cancer screening programs are costly to be established in low-and-middle income countries. Recently, we described the development of the broadly protective, thermostable vaccine antigen Trx-8mer-OVX313 based on the insertion of eight different minor capsid protein L2 neutralization epitopes into a thioredoxin scaffold from the hyperthermophilic archaeon Pyrococcus furiosus and conversion of the resulting antigen into a nanoparticle format (median radius ~9 nm) upon fusion with the heptamerizing OVX313 module. Here we evaluated whether the engineered thioredoxin scaffold, in addition to humoral immune responses, can induce CD8+ T-cell responses upon incorporation of MHC-I-restricted epitopes. By systematically examining the contribution of individual antigen modules, we demonstrated that B-cell and T-cell epitopes can be combined into a single antigen construct without compromising either immunogenicity. While CD8+ T-cell epitopes had no influence on B-cell responses, the L2 polytope (8mer) and OVX313-mediated heptamerization of the final antigen significantly increased CD8+ T-cell responses. In a proof-of-concept experiment, we found that vaccinated mice remained tumor-free even after two consecutive tumor challenges, while unvaccinated mice developed tumors. A cost-effective, broadly protective vaccine with both prophylactic and therapeutic properties represents a promising option to overcome the challenges associated with prevention and treatment of HPV-caused diseases.

Carcinogenesis Associated with Human Papillomavirus Infection. Mechanisms and Potential for Immunotherapy.

Human papillomavirus (HPV) infection is responsible for approximately 5% of all cancers and is associated with 30% of all pathogen-related cancers. Cervical cancer is the third most common cancer in women worldwide; about 70% of cervical cancer cases are caused by the high-risk HPVs (HR HPVs) of genotypes 16 and 18. HPV infection occurs mainly through sexual contact; however, viral transmission via horizontal and vertical pathways is also possible. After HPV infection of basal keratinocytes or ecto-endocervical transition zone cells, viral DNA persists in the episomal form. In most cases, infected cells are eliminated by the immune system. Occasionally, elimination fails, and HPV infection becomes chronic. Replication of HPVs in dividing epithelial cells is accompanied by increased expression of the E6 and E7 oncoproteins. These oncoproteins are responsible for genomic instability, disruption of the cell cycle, cell proliferation, immortalization, and malignant transformation of HPV-infected cells. Besides, E6 and E7 oncoproteins induce immunosuppression, preventing the detection of HPV-infected and transformed cells by the immune system. HPV integration into the genome of the host cell leads to the upregulation of E6 and E7 expression and contributes to HPV-associated malignization. Prophylactic HPV vaccines can prevent over 80% of HPV-associated anogenital cancers. The vaccine elicits immune response that prevents initial infection with a given HPV type but does not eliminate persistent virus once infection has occurred and does not prevent development of the HPV-associated neoplasias, which necessitates the development of therapeutic vaccines to treat chronic HPV infections and HPV-associated malignancies.

One-step detection of human papilloma viral infection using quantum dot-nucleotide interaction specificity.

Due to the close relationship between carcinogenesis and human papillomavirus (HPV), and since they are transmitted via huge number of asymptomatic carriers, the detection of HPV is really needed to reduce the risk of developing cancer. According to the best of our knowledge, our study provides the very first method for one-step detection of viral infection and if it has initiated the subsequent cancer proliferation. The proposed novel nanosystem consists of magnetic glass particles (MGPs), which were attached with DNA probe on their surface to hybridize with target DNAs. The MGP-probe-DNA hybrid was finally conjugated with CdTe/ZnSe core/shell quantum dots (QDs). The proposed detection system is based on a novel mechanism in which the MGPs separate out the target DNAs from different biological samples using external magnetic field for better and clear detection and the QDs give different fluorescent maxima for different target DNAs due to their ability to interact differently with different nucleotides. Firstly, the method was optimized using HPV genes cloned into synthetic plasmids. Then it was applied directly on the samples from normal and cancerous cells. After that, the real hospital samples of head and neck squamous cell carcinoma (HNSCC) with or without the infection of HPV were also analyzed. Our novel nano-system is proved successful in detecting and distinguishing between the patients suffering by HPV infection with or without subsequent cancer having detection limit estimated as 1.0 x 109 (GEq/mL). The proposed methodology is faster and cost-effective, which can be applied at the clinical level to help the doctors to decide the strategy of medication that may save the life of the patients with an early treatment.

E6 Oncoproteins from High-Risk Human Papillomavirus Induce Mitochondrial Metabolism in a Head and Neck Squamous Cell Carcinoma Model.

Head and neck squamous cell carcinoma (HNSCC) cells that are positive for human papillomavirus (HPV+) favor mitochondrial metabolism rather than glucose metabolism. However, the involvement of mitochondrial metabolism in HNSCC HPV+ cells is still unknown. The aim of this work was to evaluate the role of E6 oncoproteins from HPV16 and HPV18 in the mitochondrial metabolism in an HNSCC model. We found that E6 from both viral types abates the phosphorylation of protein kinase B-serine 473 (pAkt), which is associated with a shift in mitochondrial metabolism. E6 oncoproteins increased the levels of protein subunits of mitochondrial complexes (I to IV), as well as the ATP synthase and the protein levels of the voltage dependent anion channel (VDAC). Although E6 proteins increased the basal and leak respiration, the ATP-linked respiration was not affected, which resulted in mitochondrial decoupling. This increase in leak respiration was associated to the induction of oxidative stress (OS) in cells expressing E6, as it was observed by the fall in the glutathione/glutathione disulfide (GSH/GSSG) rate and the increase in reactive oxygen species (ROS), carbonylated proteins, and DNA damage. Taken together, our results suggest that E6 oncoproteins from HPV16 and HPV18 are inducers of mitochondrial metabolism.

Structure, Genome, Infection Cycle and Clinical Manifestations Associated with Human Papillomavirus.

A small, non-enveloped, obligatory parasite, Human papillomavirus (HPV) is known to be the cause of a range of malignancies. These entail benign infections like genital warts as well as malignant, life-threatening conditions such as cervical cancer. Since a very high mortality rate is associated with HPV caused cancers (cervical cancer is a 2nd leading cause of death caused due to cancer among women globally), there is an escalating need to understand and search for ways to combat such medical conditions. Under the same light, the given article provides an insight into the world of this versatile pathogen. Distinct aspects related to HPV have been discussed here. Emphasis has been laid upon the composition, function and assembly of capsid proteins (structural studies) and various genetic elements and their gene products (genomic studies). The essence of the mechanism behind the development of persistent infection and modes responsible for the transmission of the infectious particles has been briefly covered. Finally, the review outlines various infections and diseases caused by HPV with a major focus on their clinical and histological manifestations.

HPV-negative tumors of the uterine cervix.

Human papillomaviruses (HPV) are the causative agents of virtually all cervical carcinomas. Nevertheless, a small proportion of cervical cancer are negative for HPV, although the significance of this finding remains unclear. We aimed to provide insight into the differential clinico-pathological characteristics of this unusual subset of HPV-negative cervical cancer. We performed HPV-DNA detection using a highly sensitive PCR test (SPF10) and p16 immunostaining in 214 cervical carcinomas specimens from women treated at the Gynecological Oncology Unit of the Hospital Clinic (Barcelona, Spain) from 2012 to 2015. The clinical and pathological characteristics, including disease-free survival and overall survival, of HPV-negative and -positive cervical carcinomas were compared. Twenty-one out of 214 tumors (10%) were negative for HPV DNA. HPV-negative tumors were more frequently of the non-squamous type (9/21, 43% vs. 37/193, 19%; p < 0.01) and showed negative p16 staining (9/21; 43% vs. 7/193; 4%; p < 0.01). HPV-negative tumors were more frequently diagnosed at advanced FIGO stage (19/21, 91% vs. 110/193, 57%; p < 0.01) and more frequently had lymph node metastases (14/21, 67% vs. 69/193, 36%; p < 0.01). Patients with HPV-negative cervical cancer had a significantly worse disease-free survival (59.8 months, 95% confidence interval 32.0-87.6 vs. 132.2 months, 95% confidence interval 118.6-145.8; p < 0.01) and overall survival (77.0 months, 95% confidence interval 47.2-106.8 vs. 153.8 months, 95% confidence interval 142.0-165.6; p = 0.01) than women with HPV-positive tumors. However, only advanced FIGO stage and lymph node metastases remained associated with a poor disease-free survival and overall survival on multivariate analysis. In conclusion, our results suggest that a low percentage of cervical cancer arise via an HPV-independent pathway. These HPV-negative tumors are diagnosed at advanced stages, show higher prevalence of lymph nodes metastases and have an impaired prognosis.

Human papillomaviruses' proteins with clinical utility.

Cervical cancer, the fourth leading cause of cancer-associated deaths among women worldwide, is associated with human papilloma virus (HPV) infection. Despite the prophylactic HPV vaccination and the implementation of cervical and HPV-based screening programs, a significant increase in cervical cancer incidence is estimated by the year 2020. Thus, further development of diagnostic tools that allow detection and risk assesment in genital HPV infection is necessary. A special interest is focused on the HPV viral proteins whose expression might be of use either as primary screening tool or in conjunction with other markers (cellular proteins, HPV DNA, PAP test).

N-terminal truncations on L1 proteins of human papillomaviruses promote their soluble expression in Escherichia coli and self-assembly in vitro.

Human papillomavirus (HPV) is the causative agent in genital warts and nearly all cervical, anogenital, and oropharyngeal cancers. Nine HPV types (6, 11, 16, 18, 31, 33, 45, 52, and 58) are associated with about 90% of cervical cancers and 90% of genital warts. HPV neutralization by vaccine-elicited neutralizing antibodies can block viral infection and prevent HPV-associated diseases. However, there is only one commercially available HPV vaccine, Gardasil 9, produced from Saccharomyces cerevisiae that covers all nine types, raising the need for microbial production of broad-spectrum HPV vaccines. Here, we investigated whether N-terminal truncations of the major HPV capsid proteins L1, improve their soluble expression in Escherichia coli. We found that N-terminal truncations promoted the soluble expression of HPV 33 (truncated by 10 amino acids [aa]), 52 (15 aa), and 58 (10 aa). The resultant HPV L1 proteins were purified in pentamer form and extensively characterized with biochemical, biophysical, and immunochemical methods. The pentamers self-assembled into virus-like particles (VLPs) in vitro, and 3D cryo-EM reconstructions revealed that all formed T = 7 icosahedral particles having 50-60-nm diameters. Moreover, we formulated a nine-valent HPV vaccine candidate with aluminum adjuvant and L1 VLPs from four genotypes used in this study and five from previous work. Immunogenicity assays in mice and non-human primates indicated that this HPV nine-valent vaccine candidate elicits neutralizing antibody titers comparable to those induced by Gardasil 9. Our study provides a method for producing a nine-valent HPV vaccine in E. coli and may inform strategies for the soluble expression of other vaccine candidates.

Purification of human papillomavirus-like particles expressed in silkworm using a Bombyx mori nucleopolyhedrovirus bacmid expression system.

A three-stage chromatography protocol for the purification of human papillomavirus-like particles (HPV-LPs) from the silkworm-based Bombyx mori nucleopolyhedrovirus bacmid expression system was developed. For host cell DNA separation, anion exchange chromatography was used after screening for a suitable stationary phase. Using the two separation principles of cation exchange chromatography and metal affinity of ceramic hydroxyapatite (CHT) as a second stage, the amount of baculovirus in the sample was reduced to less than the detection limit of qPCR. The CHT separation was optimized with respect to the elution buffer used; 150-600 mM sodium phosphate, pH 7.2, resulted in the highest recovery of HPV-LPs. Using heparin chromatography, it was possible to reduce the sample volume and to thus highly concentrate the target protein during the separation of contaminating proteins. During the second purification stage, over 99.3% of the DNA was removed, and no infectious baculoviruses remained. After concentration by heparin column chromatography, over 99.9% of the DNA and protein had been removed. The purity achieved by this method exceeds that obtained by DDDDK-tag-based affinity chromatography and sucrose gradient ultracentrifugation, which were used as comparative purification methods. The 3-stage purification of HPV-LPs from silkworm fat bodies described here was a proof of concept and is a scalable method, but the overall yield remains to be improved.

Identification of G-quadruplex forming sequences in three manatee papillomaviruses.

The Florida manatee (Trichechus manatus latirotris) is a threatened aquatic mammal in United States coastal waters. Over the past decade, the appearance of papillomavirus-induced lesions and viral papillomatosis in manatees has been a concern for those involved in the management and rehabilitation of this species. To date, three manatee papillomaviruses (TmPVs) have been identified in Florida manatees, one forming cutaneous lesions (TmPV1) and two forming genital lesions (TmPV3 and TmPV4). We identified DNA sequences with the potential to form G-quadruplex structures (G4) across the three genomes. G4 were located on both DNA strands and across coding and non-coding regions on all TmPVs, offering multiple targets for viral control. Although G4 have been identified in several viral genomes, including human PVs, most research has focused on canonical structures comprised of three G-tetrads. In contrast, the vast majority of sequences we identified would allow the formation of non-canonical structures with only two G-tetrads. Our biophysical analysis confirmed the formation of G4 with parallel topology in three such sequences from the E2 region. Two of the structures appear comprised of multiple stacked two G-tetrad structures, perhaps serving to increase structural stability. Computational analysis demonstrated enrichment of G4 sequences on all TmPVs on the reverse strand in the E2/E4 region and on both strands in the L2 region. Several G4 sequences occurred at similar regional locations on all PVs, most notably on the reverse strand in the E2 region. In other cases, G4 were identified at similar regional locations only on PVs forming genital lesions. On all TmPVs, G4 sequences were located in the non-coding region near putative E2 binding sites. Together, these findings suggest that G4 are possible regulatory elements in TmPVs.

Diverse papillomaviruses identified in Weddell seals.

Papillomaviridae is a diverse family of circular, double-stranded DNA (dsDNA) viruses that infect a broad range of mammalian, avian and fish hosts. While papillomaviruses have been characterized most extensively in humans, the study of non-human papillomaviruses has contributed greatly to our understanding of their pathogenicity and evolution. Using high-throughput sequencing approaches, we identified 7 novel papillomaviruses from vaginal swabs collected from 81 adult female Weddell seals (Leptonychotes weddellii) in the Ross Sea of Antarctica between 2014-2017. These seven papillomavirus genomes were amplified from seven individual seals, and six of the seven genomes represented novel species with distinct evolutionary lineages. This highlights the diversity of papillomaviruses among the relatively small number of Weddell seal samples tested. Viruses associated with large vertebrates are poorly studied in Antarctica, and this study adds information about papillomaviruses associated with Weddell seals and contributes to our understanding of the evolutionary history of papillomaviruses.

Presence or Absence of Significant HPVE4 Expression in High-grade Anal Intraepithelial Neoplasia With p16/Ki-67 Positivity Indicates Distinct Patterns of Neoplasia: A Study Combining Immunohistochemistry and Laser Capture Microdissection PCR.

Progression of anal intraepithelial neoplasia (AIN) involves transition from productive to transforming human papillomavirus (HPV) infection. Grading aims to distinguish productive low-grade AIN from high-grade anal intraepithelial neoplasia (HGAIN) with risk of cancer. We describe immunohistochemical patterns in AIN adding a novel marker for initiation of the productive phase of the HPV life cycle (panHPVE4) to those for cell cycle activity (Ki-67) and transforming activity of HPVE7 gene (p16). We studied 67 anal biopsies for suspected anal neoplasia (17 normal, 15 AIN1, 20 AIN2, 15 AIN3) from 54 men who have sex with men at New York Presbyterian Hospital, USA. Two pathologists generated consensus AIN and immunogrades. Whole tissue and laser capture microdissection samples from multiple HPV-infected biopsies were tested for HPV with SPF10-PCR-DEIA-LiPA25, version 1. (Para)basal Ki-67 expression distinguished normal from AIN (≥lower-third Ki-67) with sensitivity 0.92 and specificity 1.0. Ki-67 did not distinguish grades of AIN. Null/patchy p16 versus diffuse ≥lower-third patterns discriminated HGAIN (sensitivity, 1.0; specificity, 0.84). There was marked heterogeneity in E4 expression within HGAIN. Most AIN2 (14/20) was E4 versus 0/15 AIN3 (sensitivity, 0.70; specificity 1.0). HPV was detected in 63 (94%) biopsies, with 49 (77.8%) high-risk HPV. HPV16 was the most frequent (13%). Multiple HPV genotypes were found in 15 (24%) biopsies and laser capture microdissection -polymerase chain reaction confirmed specific HPV types in E4 +/- AIN. Although Ki-67 discriminated AIN and p16 HGAIN, E4/p16 staining shows that most AIN2 is different from transformed AIN3 in showing both entry into productive HPV infection and transforming activity.

Structural Insights in Multifunctional Papillomavirus Oncoproteins.

Since their discovery in the mid-eighties, the main papillomavirus oncoproteins E6 and E7 have been recalcitrant to high-resolution structure analysis. However, in the last decade a wealth of three-dimensional information has been gained on both proteins whether free or complexed to host target proteins. Here, we first summarize the diverse activities of these small multifunctional oncoproteins. Next, we review the available structural data and the new insights they provide about the evolution of E6 and E7, their multiple interactions and their functional variability across human papillomavirus (HPV) species.

An Infrared Dye-Conjugated Virus-like Particle for the Treatment of Primary Uveal Melanoma.

The work outlined herein describes AU-011, a novel recombinant papillomavirus-like particle (VLP) drug conjugate and its initial evaluation as a potential treatment for primary uveal melanoma. The VLP is conjugated with a phthalocyanine photosensitizer, IRDye 700DX, that exerts its cytotoxic effect through photoactivation with a near-infrared laser. We assessed the anticancer properties of AU-011 in vitro utilizing a panel of human cancer cell lines and in vivo using murine subcutaneous and rabbit orthotopic xenograft models of uveal melanoma. The specificity of VLP binding (tumor targeting), mediated through cell surface heparan sulfate proteoglycans (HSPG), was assessed using HSPG-deficient cells and by inclusion of heparin in in vitro studies. Our results provide evidence of potent and selective anticancer activity, both in vitro and in vivo AU-011 activity was blocked by inhibiting its association with HSPG using heparin and using cells lacking surface HSPG, indicating that the tumor tropism of the VLP was not affected by dye conjugation and cell association is critical for AU-011-mediated cytotoxicity. Using the uveal melanoma xenograft models, we observed tumor uptake following intravenous (murine) and intravitreal (rabbit) administration and, after photoactivation, potent dose-dependent tumor responses. Furthermore, in the rabbit orthotopic model, which closely models uveal melanoma as it presents in the clinic, tumor treatment spared the retina and adjacent ocular structures. Our results support further clinical development of this novel therapeutic modality that might transform visual outcomes and provide a targeted therapy for the early-stage treatment of patients with this rare and life-threatening disease. Mol Cancer Ther; 17(2); 565-74. ©2017 AACR.

Crystal Structures of Two Immune Complexes Identify Determinants for Viral Infectivity and Type-Specific Neutralization of Human Papillomavirus.

Persistent, high-risk human papillomavirus (HPV) infection is the primary cause of cervical cancer. Neutralizing antibodies elicited by L1-only virus-like particles (VLPs) can block HPV infection; however, the lack of high-resolution structures has limited our understanding of the mode of virus infection and the requirement for type specificity at the molecular level. Here, we describe two antibodies, A12A3 and 28F10, that specifically bind to and neutralize HPV58 and HPV59, respectively, through two distinct binding stoichiometries. We show that the epitopes of A12A3 are clustered in the DE loops of two adjacent HPV58 L1 monomers, whereas 28F10 recognizes the HPV59 FG loop of a single monomer. Via structure-based mutagenesis and analysis of antibody binding, we further identified the residues HPV58 D154, S168, and N170 and HPV59 M267, Q270, E273, Y276, K278, and R283, which play critical roles in virus infection. By substituting these strategic epitope residues into other HPV genotypes, we could then redirect the type-specific binding of the antibodies to these genotypes, thus highlighting the importance of these specific residues, HPV58 R161, S168, and N308 and HPV59 Q270, E273, and D281. Overall, our findings provide molecular insights into potential structural determinants of HPV required for infectivity and type specificity.IMPORTANCE High-risk human papillomaviruses (HPVs) are considered the major causative pathogens of cancers that affect epithelial mucosa, such as cervical cancer. However, because of the lack of high-resolution structural information on the sites of neutralization, we have yet to determine the precise mode of HPV infection and how different types of HPV cause infection. Our crystal structures in this study have uncovered discrete binding stoichiometries for two different antibodies. We show that one A12A3 Fab binds to the center of one HPV58 pentamer, whereas five 28F10 Fabs bind along the top fringe of one HPV59 pentamer. Furthermore, through targeted epitope analysis, we show that 6 to 7 discontinuous residues of the L1 major capsid protein of HPV are determinants, at least in part, for virus infection and type specificity. This knowledge will help us to unravel the process of HPV infection and can potentially be used to drive the development of therapeutics that target neutralization-sensitive sites.

Clinical significance of CK7, HPV-L1, and koilocytosis for patients with cervical low-grade squamous intraepithelial lesions: a retrospective analysis.

Most cervical low-grade squamous intraepithelial lesions (LSILs) do not progress to high-grade squamous intraepithelial lesions (HSILs); however, reliable biomarkers that predict LSIL progression are lacking. We investigated the association of cytokeratin 7 (CK7), human papillomavirus-L1 capsid protein (HPV-L1), and koilocytosis with clinical outcomes of patients with LSIL. CK7, HPV-L1, Ki67, and p16-INK4A expression was determined in 72 cervical LSIL and 28 HSIL biopsy samples; koilocytosis was evaluated by reviewing biopsy slides. Fifty patients with LSIL received follow-up. CK7, HPV-L1, and koilocytosis were detected in 48.6%, 44.4%, and 52.0% of LSIL tissues and in 78.6%, 10.7%, and 64.3% of HSIL tissues, respectively. Lesion grade was correlated directly with CK7 expression (P=.007) and inversely with HPV-L1 expression (P=.004). CK7 expression in LSILs was correlated inversely with HPV-L1 expression and directly with p16-INK4A and Ki67 status. Furthermore, koilocytosis was significantly associated with HPV-L1 and p16-INK4A expression. Progression to cervical intraepithelial lesions of grades ≥2 occurred in 34% of cases. CK7 negativity and HPV-L1 positivity were significantly associated with lower HSIL progression rates. HPV-L1-positive and CK7-negative LSILs showed significantly lower progression rates compared with HPV-L1-negative and CK7-positive LSILs (6.3% v-positive cases showed a significantly lower progression rate (17.6%) compared with nonkoilocytic and HPV-L1-negative cases (50%). CK7-negative, HPV-L1-positive, and koilocytic LSILs showed a progression rate of 7.7%. Koilocytosis and p16-INK4A were not significantly associated with clinical outcomes. Hence, evaluating HPV-L1, CK7, and koilocytosis profiles combined may be more reliable for LSIL prognostication.

Quadrivalent vaccine-targeted human papillomavirus genotypes in heterosexual men after the Australian female human papillomavirus vaccination programme: a retrospective observational study.

BACKGROUND: Australia introduced a national quadrivalent human papillomavirus (4vHPV) vaccination programme for girls and young women in April, 2007. The HPV genotypes targeted by the female vaccine could also affect the protection afforded to heterosexual men. We examined the prevalence of 4vHPV targeted vaccine genotypes and the nine-valent HPV (9vHPV)-targeted vaccines genotypes among sexually active, predominantly unvaccinated heterosexual men from 2004 to 2015. METHODS: We did a retrospective, observational study of urine and urethral swab specimens from heterosexual men aged 25 years or younger attending the Melbourne Sexual Health Centre between July 1, 2004, and June 30, 2015, who tested positive for Chlamydia trachomatis. We extracted HPV DNA and used the PapType HPV assay to detect 14 high-risk HPV genotypes (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) and two low-risk genotypes (6 and 11). We calculated the prevalence of any HPV genotype, genotypes 6 or 11, genotypes 16 or 18, genotypes in the 4vHPV group (6, 11, 16, or 18), five additional genotypes in the 9vHPV group (31, 33, 45, 52, or 58), and non-vaccine-targeted genotypes (31, 33, 35, 39, 45, 51, 56, 58, 59, 66, or 68). FINDINGS: We obtained data between July 1, 2004, and June 30, 2015, and did the data analysis in December, 2015. Of 1764 specimens obtained, we included 1466 in our final analysis (the others were excluded because they had indeterminate results or were duplicates). The prevalence of any HPV genotype and genotypes 31, 33, 45, 52, and 58 did not change from 2004-05 to 2014-15, but we noted reductions in genotypes 6 and 11 (from 12% [95% CI 6-21%], to 3% [1-7%], ptrend=0·008), 16 and 18 (from 13% [95% CI 7-22%] to 3% [1-6%], ptrend<0·0001), and 4vHPV-targeted genotypes (from 22% [95% CI 14-33%] to 6% [3-10%], ptrend<0·0001). Prevalence of non-vaccine-targeted genotypes increased from 16% [95% CI 9-26%] to 22% [17-29%], ptrend<0·0001). In Australian-born men, 4vHPV-targeted genotype prevalence decreased from 11 of 55 [20%, 95% CI 10-33%] to two of 74 [3%, 0-11%], ptrend<0·0001); an even greater decline occurred in Australian-born men aged 21 years or younger (from four of 13 [31%, 95% CI 9-61%] to none of 25; ptrend<0·0001). Genotypes 16 and 18 decreased (adjusted prevalence ratio [PR] 0·32, 95% CI 0·14-0·74; p=0·008) but not genotypes 6 and 11 (adjusted PR 0·50, 0·16-1·56; p=0·234) in the postvaccination period among men who had arrived in Australia within 2 years from countries with a bivalent vaccine (2vHPV) programme (England, Scotland, Wales, Cook Islands, Northern Ireland, or the Netherlands), compared with the prevaccination period. No change was noted in 4vHPV genotypes in men born overseas in other countries. INTERPRETATION: The marked reduction in prevalence of 4vHPV genotypes among mainly unvaccinated Australian-born men suggests herd protection has occurred from the female vaccination programme. Additionally, the decline in genotypes 16 and 18, but not genotypes 6 and 11, among overseas-born men predominantly from countries with a 2vHPV vaccine programme suggests that these men received benefits from herd protection for genotypes 16 and 18 from their vaccinated female partners in their own countries. These reductions could translate to reductions in HPV-related malignant conditions in men, even in countries with female-only vaccination programmes. FUNDING: The Australian National Health and Medical Research Council Program.

Cross-reactivity of antigens and antibodies belonging to different pathogenic types of human papillomaviruses.

The analysis of the properties of a quadrivalent peroral vaccine against the cervical cancer, which was created in a plant expression system on the base of transgenic tomato fruits, by immunoassay and Western blot hybridization showed that the antibodies against human papilloma virus 16 L1 (HPV16 L1) actively interacted not only with the antigenic proteins HPV18 L1, HPV31 L1, and HPV45 L1, but also with the antigenic protein HPV6 L1, which belongs to another HPV family. Thus, new data on the possibility of crossreactivity between antibodies and antigens belonging to remote HPV families were obtained.