Human papillomavirus infection: Epidemiology, biology, host interactions, cancer development, prevention, and therapeutics

Human papillomavirus (HPV) infection is one of the most common sexually transmitted infections worldwide. It is caused by the HPV, a DNA virus that infects epithelial cells in various mucous membranes and skin surfaces. HPV can be categorised into high-risk and low-risk types based on their association with the development of certain cancers. High-risk HPV types, such as HPV-16 and HPV-18, are known to be oncogenic and are strongly associated with the development of cervical, anal, vaginal, vulvar, penile, and oropharyngeal cancers. These types of HPV can persist in the body for an extended period and, in some cases, lead to the formation of precancerous lesions that may progress to cancer if left untreated. Low-risk HPV types, such as HPV-6 and HPV-11, are not typically associated with cancer but can cause benign conditions like genital warts. Genital warts are characterised by the growth of small, cauliflower-like bumps on the genital and anal areas. Although not life-threatening, they can cause discomfort and psychological distress. HPV is primarily transmitted through sexual contact, including vaginal, anal, and oral sex. It can also be transmitted through non-penetrative sexual activities that involve skin-to-skin contact. In addition to sexual transmission, vertical transmission from mother to child during childbirth is possible but relatively rare. Prevention of HPV infection includes vaccination and safe sexual practices. HPV vaccines, such as Gardasil and Cervarix, are highly effective in preventing infection with the most common high-risk HPV types. These vaccines are typically administered to adolescents and young adults before they become sexually active. Safe sexual practices, such as consistent and correct condom use and limiting the number of sexual partners, can also reduce the risk of HPV transmission. Diagnosis of HPV infection can be challenging because the infection is often asymptomatic, especially in men. In women, HPV testing can be done through cervical screening programs, which involve the collection of cervical cells for analysis. Abnormal results may lead to further diagnostic procedures, such as colposcopy or biopsy, to detect precancerous or cancerous changes. Overall, HPV infection is a prevalent sexually transmitted infection with significant implications for public health. Vaccination, regular screening, and early treatment of precancerous lesions are key strategies to reduce the burden of HPV-related diseases and their associated complications. Education and awareness about HPV and its prevention are crucial in promoting optimal sexual health. This study aimed to carry out a literature review considering several aspects involving HPV infection: Global distribution, prevalence, biology, host interactions, cancer development, prevention, therapeutics, coinfection with other viruses, coinfection with bacteria, association with head and neck squamous cell carcinomas, and association with anal cancer.

Mechanistic Contributions of lncRNAs to Cellular Signaling Pathways Crucial to the Lifecycle of Human Papillomaviruses

Papillomaviruses are ubiquitous epitheliotropic viruses with double-stranded circular DNA genomes of approximately 8000 base pairs. The viral life cycle is somewhat unusual in that these viruses can establish persistent infections in the mitotically active basal epithelial cells that they initially infect. High-level viral genome replication ("genome amplification"), the expression of capsid proteins, and the formation of infectious progeny are restricted to terminally differentiated cells where genomes are synthesized at replication factories at sites of double-strand DNA breaks. To establish persistent infections, papillomaviruses need to retain the basal cell identity of the initially infected cells and restrain and delay their epithelial differentiation program. To enable high-level viral genome replication, papillomaviruses also need to hold the inherently growth-arrested terminally differentiated cells in a replication-competent state. To provide ample sites for viral genome synthesis, they target the DNA damage and repair machinery. Studies focusing on delineating cellular factors that are targeted by papillomaviruses may aid the development of antivirals. Whilst most of the current research efforts focus on protein targets, the majority of the human transcriptome consists of noncoding RNAs. This review focuses on one specific class of noncoding RNAs, long noncoding RNAs (lncRNAs), and summarizes work on lncRNAs that may regulate the cellular processes that are subverted by papillomavirus to enable persistent infections and progeny synthesis.

Investigating immune and non-immune cell interactions in head and neck tumors by single-cell RNA sequencing

Head and neck squamous cell carcinoma (HNSCC) is characterized by complex relations between stromal, epithelial, and immune cells within the tumor microenvironment (TME). To enable the development of more efficacious therapies, we aim to study the heterogeneity, signatures of unique cell populations, and cell-cell interactions of non-immune and immune cell populations in 6 human papillomavirus (HPV)+ and 12 HPV- HNSCC patient tumor and matched peripheral blood specimens using single-cell RNA sequencing. Using this dataset of 134,606 cells, we show cell type-specific signatures associated with inflammation and HPV status, describe the negative prognostic value of fibroblasts with elastic differentiation specifically in the HPV+ TME, predict therapeutically targetable checkpoint receptor-ligand interactions, and show that tumor-associated macrophages are dominant contributors of PD-L1 and other immune checkpoint ligands in the TME. We present a comprehensive single-cell view of cell-intrinsic mechanisms and cell-cell communication shaping the HNSCC microenvironment.

Impact of human papillomavirus infection on semen parameters and reproductive outcomes

BACKGROUND

Human papillomavirus (HPV) has been shown to adversely affect human reproduction. We aimed to evaluate the prevalence of human papillomavirus (HPV) infection in men and its correlation with semen parameters and reproductive outcomes.

METHODS

Semen samples and penile swabs were collected from potential sperm donors (SD, n = 97) and male partners of infertile couples (IM, n = 328). The presence of HPV DNA in semen samples and penile swabs was analyzed. Associations between hrHPV positive status and fertility outcomes as well as socio-behavioral and health characteristics were evaluated using the R software package.

RESULTS

High-risk HPV (hrHPV) genotypes were detected in 28.9% of SD and 35.1% of IM (P = 0.312). Penile swabs were more frequently positive for hrHPV genotypes than semen samples in both IM (32.3% vs. 11.9%, P < 0.001) and SD (26.8% vs. 6.2%, P = 0.006). Men with hrHPV positive semen samples had lower semen volume (median volume 2.5 ml vs. 3 ml, P = 0.009), sperm concentration (median concentration 16 × 10⁶/ml vs. 31 × 10⁶/ml, P = 0.009) and total sperm count (median count 46 × 10⁶ vs. 82 × 10⁶, P = 0.009) than men with hrHPV negative samples. No association was identified between penile hrHPV status and semen parameters.

CONCLUSIONS

Our findings indicate that penile HPV infection is common in both potential sperm donors and men from infertile couples. Although HPV positivity is higher in penile swabs, only HPV infection in semen samples affects sperm parameters. However, there was no association between hrHPV positivity in semen and fertility outcomes including abortion rate.

Mouse Papillomavirus L1 and L2 Are Dispensable for Viral Infection and Persistence at Both Cutaneous and Mucosal Tissues

Papillomavirus L1 and L2, the major and minor capsid proteins, play significant roles in viral assembly, entry, and propagation. In the current study, we investigate the impact of L1 and L2 on viral life cycle and tumor growth with a newly established mouse papillomavirus (MmuPV1) infection model. MmuPV1 L1 knockout, L2 knockout, and L1 plus L2 knockout mutant genomes (designated as L1ATGko-4m, L2ATGko, and L1-L2ATGko respectively) were generated. The mutants were examined for their ability to generate lesions in athymic nude mice. Viral activities were examined by qPCR, immunohistochemistry (IHC), in situ hybridization (ISH), and transmission electron microscopy (TEM) analyses. We demonstrated that viral DNA replication and tumor growth occurred at both cutaneous and mucosal sites infected with each of the mutants. Infections involving L1ATGko-4m, L2ATGko, and L1-L2ATGko mutant genomes generally resulted in smaller tumor sizes compared to infection with the wild type. The L1 protein was absent in L1ATGko-4m and L1-L2ATGko mutant-treated tissues, even though viral transcripts and E4 protein expression were robust. Therefore, L1 is not essential for MmuPV1-induced tumor growth, and this finding parallels our previous observations in the rabbit papillomavirus model. Very few viral particles were detected in L2ATGko mutant-infected tissues. Interestingly, the localization of L1 in lesions induced by L2ATGko was primarily cytoplasmic rather than nuclear. The findings support the hypothesis that the L2 gene influences the expression, location, transport, and assembly of the L1 protein in vivo.

Episome partitioning and symmetric cell divisions: Quantifying the role of random events in the persistence of HPV infections

Human Papillomaviruses (HPV) are one of the most prevalent sexually transmitted infections (STI) and the most oncogenic viruses known to humans. The vast majority of HPV infections clear in less than 3 years, but the underlying mechanisms, especially the involvement of the immune response, are still poorly known. Building on earlier work stressing the importance of randomness in the type of cell divisions in the clearance of HPV infection, we develop a stochastic mathematical model of HPV dynamics that combines the previous aspect with an explicit description of the intracellular level. We show that the random partitioning of virus episomes upon stem cell division and the occurrence of symmetric divisions dramatically affect viral persistence. These results call for more detailed within-host studies to better understand the relative importance of stochasticity and immunity in HPV infection clearance.

Every year, infections by Human Papillomaviruses (HPV) are responsible for a large share of infectious cancers. The prevalence of HPVs is very high, which makes it a major public health issue. Fortunately, most HPV infections (80 to 90%) are cleared naturally within three years. Among the few that persist into chronic infections, the majority also naturally regress. Hence for a given HPV infection, the risk of progression towards cancerous status is low. The immune response is often invoked to explain HPV clearance in non-persisting infections, but many uncertainties remain. Besides immunity, randomness was also suggested to play an important role. Here, we examine how random events occurring during the life cycle of the virus could alter the persistence of the virus inside the host. We develop a mechanistic model that explicitly follows the dynamic of viral copies inside host cells, as well as the dynamics of the epithelium. In our model, infection extinction occurs when all viral copies end up in differentiated cells and migrate towards the surface. This can happen upon cell division during the random allocation of the episomes (i.e. independent circular DNA copies of the viral genome) or when a stem cell divides symmetrically to generate two differentiated cells. We find that the combination of these random events drastically affects infection persistence. More generally, the importance of random fluctuations could match that of immunity and calls for further studies at the within-host and the epidemiological level.

K-Mer Analyses Reveal Different Evolutionary Histories of Alpha, Beta, and Gamma Papillomaviruses

Papillomaviruses (PVs) are a heterogeneous group of DNA viruses that can infect fish, birds, reptiles, and mammals. PVs infecting humans (HPVs) phylogenetically cluster into five genera (Alpha-, Beta-, Gamma-, Mu- and Nu-PV), with differences in tissue tropism and carcinogenicity. The evolutionary features associated with the divergence of Papillomaviridae are not well understood. Using a combination of k-mer distributions, genetic metrics, and phylogenetic algorithms, we sought to evaluate the characteristics and differences of Alpha-, Beta- and Gamma-PVs constituting the majority of HPV genomes. A total of 640 PVs including 442 HPV types, 27 non-human primate PV types, and 171 non-primate animal PV types were evaluated. Our analyses revealed the highest genetic diversity amongst Gamma-PVs compared to the Alpha and Beta PVs, suggesting reduced selective pressures on Gamma-PVs. Using a sequence alignment-free trimer (k = 3) phylogeny algorithm, we reconstructed a phylogeny that grouped most HPV types into a monophyletic clade that was further split into three branches similar to alignment-based classifications. Interestingly, a subset of low-risk Alpha HPVs (the species Alpha-2, 3, 4, and 14) split from other HPVs and were clustered with non-human primate PVs. Surprisingly, the trimer-constructed phylogeny grouped the Gamma-6 species types originally isolated from the cervicovaginal region with the main Alpha-HPV clade. These data indicate that characterization of papillomavirus heterogeneity via orthogonal approaches reveals novel insights into the biological understanding of HPV genomes.

The ability of post-chemoradiotherapy DWI ADCmean and 18F-FDG SUVmax to predict treatment outcomes in head and neck cancer: impact of human papilloma virus oropharyngeal cancer status

OBJECTIVES

To evaluate the ability of post-chemo-radiotherapy (CRT) diffusion-weighted-MRI apparent diffusion coefficient (ADCmean) and 18F-FDG PET maximum standardized uptake value (SUVmax) to predict disease-free survival (DFS) in head and neck squamous cell carcinoma (HNSCC), and to determine whether this ability is influenced by human papillomavirus oropharyngeal cancer (HPV-OPC) status.

METHODS

This prospective cohort observational study included 65 participants (53 male, mean ± SD age 59.9 ± 7.9 years, 46 HPV-OPC) with stage III or IV HNSCC. Primary tumour and nodal ADCmean (pre-treatment, 6- and 12-weeks post-CRT) and SUVmax (12-weeks post-CRT) were measured. Variables were compared with 2-year DFS (independent t-test/Mann-Whitney test) and overall DFS (Cox regression), before and after accounting for HPV-OPC status. Variables were also compared between HPV-OPC and other HNSCC subgroups after stratifying for DFS.

RESULTS

Absolute post-CRT ADCmean values predicted 2-year DFS and overall DFS for all participants (p = 0.03/0.03, 6-week node; p = 0.02/0.03 12-week primary tumour) but not in the HPV-OPC subgroup. In participants with DFS, percentage interval changes in primary tumour ADCmean at 6- and 12-weeks were higher in HPV-OPC than other HNSCC (p = 0.01, 6 weeks; p = 0.005, 12 weeks). The 12-week post-CRT SUVmax did not predict DFS.

CONCLUSION

Absolute post-CRT ADCmean values predicted DFS in HNSCC but not in the HPV-OPC subgroup. Amongst participants with DFS, post-CRT percentage interval changes in primary tumour ADCmean were significantly higher in HPV-OPC than in other HNSCC. Knowledge of HPV-OPC status is crucial to the clinical utilisation of post-CRT DWI-MRI for the prediction of outcomes.

Humans with inherited T cell CD28 deficiency are susceptible to skin papillomaviruses but are otherwise healthy

We study a patient with the human papilloma virus (HPV)-2-driven "tree-man" phenotype and two relatives with unusually severe HPV4-driven warts. The giant horns form an HPV-2-driven multifocal benign epithelial tumor overexpressing viral oncogenes in the epidermis basal layer. The patients are unexpectedly homozygous for a private CD28 variant. They have no detectable CD28 on their T cells, with the exception of a small contingent of revertant memory CD4+ T cells. T cell development is barely affected, and T cells respond to CD3 and CD2, but not CD28, costimulation. Although the patients do not display HPV-2- and HPV-4-reactive CD4+ T cells in vitro, they make antibodies specific for both viruses in vivo. CD28-deficient mice are susceptible to cutaneous infections with the mouse papillomavirus MmuPV1. The control of HPV-2 and HPV-4 in keratinocytes is dependent on the T cell CD28 co-activation pathway. Surprisingly, human CD28-dependent T cell responses are largely redundant for protective immunity.

A Retrospective Study and Literature Review of Cervical Villoglandular Adenocarcinoma: A Candidate Paradigm of Silva System Pattern A

The aim was to investigate the clinicopathologic characters of cervical villoglandular adenocarcinoma (VGA), the authors retrospectively reviewed 4 cases of VGA, including clinical characteristics, pathology, managements, together with outcome information. The median age of the patients was 42 (range: 37 to 58), with 3 of them presenting with stage IB disease and 1 presenting with IVB. Human papillomavirus infection was tested in 3 of the patients, with all positive with high-risk type. Three of the patients underwent a radical hysterectomy with bilateral salpingo-oophorectomy plus bilateral pelvic lymphadenectomy, and 2 of them underwent subsequent chemotherapy. One patient received a bilateral salpingo-oophorectomy plus pelvic and periaortic lymphadenectomy and postoperative radiochemotherapy. Lymph node metastasis was detected in 1 patient. The follow-up time ranged from 56 to 120 months (median: 70 mo). Except for 1 person who experienced recurrence, all patients are alive at present and no recurrence occurred. In conclusion, VGA is a rare subtype of adenocarcinoma of the uterine cervix with distinct exophytic, villous-papillary growth pattern and extremely excellent prognosis, which corresponds with pattern A in Silva system, while its underlying mechanism and genetic background is still far from well known.

HPV and Other Microbiota; Who's Good and Who's Bad: Effects of the Microbial Environment on the Development of Cervical Cancer-A Non-Systematic Review

Cervical cancer is responsible for around 5% of all human cancers worldwide. It develops almost exclusively from an unsolved, persistent infection of the squamocolumnar transformation zone between the endo- and ecto-cervix with various high-risk (HR) human papillomaviruses (HPVs). The decisive turning point on the way to persistent HPV infection and malignant transformation is an immune system weakened by pathobionts and oxidative stress and an injury to the cervical mucosa, often caused by sexual activities. Through these injury and healing processes, HPV viruses, hijacking activated keratinocytes, move into the basal layers of the cervical epithelium and then continue their development towards the distal prickle cell layer (Stratum spinosum). The microbial microenvironment of the cervical tissue determines the tissue homeostasis and the integrity of the protective mucous layer through the maintenance of a healthy immune and metabolic signalling. Pathological microorganisms and the resulting dysbiosis disturb this signalling. Thus, pathological inflammatory reactions occur, which manifest the HPV infection. About 90% of all women contract an HPV infection in the course of their lives. In about 10% of cases, the virus persists and cervical intra-epithelial neoplasia (CIN) develops. Approximately 1% of women with a high-risk HPV infection incur a cervical carcinoma after 10 to 20 years. In this non-systematic review article, we summarise how the sexually and microbial mediated pathogenesis of the cervix proceeds through aberrant immune and metabolism signalling via CIN to cervical carcinoma. We show how both the virus and the cancer benefit from the same changes in the immune and metabolic environment.

Analysis of HPV Integrations in Mexican Pre-Tumoral Cervical Lesions Reveal Centromere-Enriched Breakpoints and Abundant Unspecific HPV Regions

Human papillomavirus (HPV) DNA integration is a crucial event in cervical carcinogenesis. However, scarce studies have focused on studying HPV integration (HPVint) in early-stage cervical lesions. Using HPV capture followed by sequencing, we investigated HPVint in pre-tumor cervical lesions. Employing a novel pipeline, we analyzed reads containing direct evidence of the integration breakpoint. We observed multiple HPV infections in most of the samples (92%) with a median integration rate of 0.06% relative to HPV mapped reads corresponding to two or more sequence breakages. Unlike cancer studies, most integrations events were unique (supported by one read), consistent with the lack of clonal selection. Congruent to other studies, we found that breakpoints could occur, practically, in any part of the viral genome. We noted that L1 had a higher frequency of rupture integration (25%). Based on host genome integration frequencies, we found previously reported integration sites in cancer for genes like FHIT, CSMD1, and LRP1B and putatively many new ones such as those exemplified in CSMD3, ROBO2, and SETD3. Similar host integrations regions and genes were observed in diverse HPV types within many genes and even equivalent integration positions in different samples and HPV types. Interestingly, we noted an enrichment of integrations in most centromeres, suggesting a possible mechanism where HPV exploits this structural machinery to facilitate integration. Supported by previous findings, overall, our analysis provides novel information and insights about HPVint.

Persistent Human Papillomavirus Infection

Simple Summary

The success of HPV as an infectious agent lies not within its ability to cause disease, but rather in the adeptness of the virus to establish long-term persistent infection. The ability of HPV to replicate and maintain its genome in a stratified epithelium is contingent on the manipulation of many host pathways. HPVs must abrogate host anti-viral defense programs, perturb the balance of cellular proliferation and differentiation, and hijack DNA damage signaling and repair pathways to replicate viral DNA in a stratified epithelium. Together, these characteristics contribute to the ability of HPV to achieve long-term and persistent infection and to its evolutionary success as an infectious agent.

Abstract

Persistent infection with oncogenic human papillomavirus (HPV) types is responsible for ~5% of human cancers. The HPV infectious cycle can sustain long-term infection in stratified epithelia because viral DNA is maintained as low copy number extrachromosomal plasmids in the dividing basal cells of a lesion, while progeny viral genomes are amplified to large numbers in differentiated superficial cells. The viral E1 and E2 proteins initiate viral DNA replication and maintain and partition viral genomes, in concert with the cellular replication machinery. Additionally, the E5, E6, and E7 proteins are required to evade host immune responses and to produce a cellular environment that supports viral DNA replication. An unfortunate consequence of the manipulation of cellular proliferation and differentiation is that cells become at high risk for carcinogenesis.

Conjunctival cancer in people living with HIV

PURPOSE OF REVIEW

Historically, conjunctival cancer has been associated with HIV particularly in sub-Saharan Africa. The human papilloma virus (HPV) has been implicated as a potential causative agent without conclusive evidence. This review covers recent evidence of the epidemiology, diagnosis and treatment of conjunctival cancer in people living with HIV (PLWH).

RECENT FINDINGS

HIV infection has been attributed to 33% of squamous cell carcinoma of the conjunctiva in sub-Saharan Africa. Although clear evidence of the effect of immunodeficiency on conjunctival cancer risk has been demonstrated, the role of HPV on conjunctival cancer development is still unclear. Biomarkers such as the p16 protein are not always indicative of HPV infection. The Epstein-Barr virus (EBV) might potentially be another infectious agent of interest in the development of conjunctival cancer. There is some evidence of increased conjunctival cancer recurrence post treatment as well as increased probability of metastasis in PLWH.

SUMMARY

Immunodeficiency increases the risk of conjunctival cancer in PLWH. Symptomatic screening of conjunctival cancer in PLWH should be encouraged. Research on HPV involvement should remain a priority and EBV considered as another etiologic agent of interest. More studies on treatment modalities in PLWH should be considered.

The environmental pollutant and tobacco smoke constituent dibenzo[def,p]chrysene is a co-factor for malignant progression of mouse oral papillomavirus infections

HPV infections in the oral cavity that progress to cancer are on the increase in the USA. Model systems to study co-factors for progression of these infections are lacking as HPVs are species-restricted and cannot grow in preclinical animal models. We have recently developed a mouse papillomavirus (MmuPV1) oral mucosal infection model that provides opportunities to test, for the first time, the hypothesis that tobacco carcinogens are co-factors that can impact the progression of oral papillomas to squamous cell carcinoma (SCC). Four cohorts of mice per sex were included: (1) infected with MmuPV1 and treated orally with DMSO-saline; (2) infected with MmuPV1 and treated orally with the tobacco carcinogen, dibenzo[def,p]chrysene (DBP); (3) uninfected and treated orally with DMSO-saline, and (4) uninfected and treated orally with DBP. Oral swabs were collected monthly for subsequent assessment of viral load. Oral tissues were collected for in situ viral DNA/RNA detection, viral protein staining, and pathological assessment for hyperplasia, papillomas and SCC at study termination. We observed increased rates of SCC in oral tissue infected with MmuPV1 and treated with DBP when compared to mice treated with DBP or virus individually, each of which showed minimal disease. Virally-infected epithelium showed strong levels of viral DNA/RNA and viral protein E4/L1 staining. In contrast, areas of SCC showed reduced viral DNA staining indicative of lower viral copy per nucleus but strong RNA signals. Several host markers (p120 ctn, p53, S100A9) were also examined in the mouse oral tissues; of particular significance, p120 ctn discriminated normal un-infected epithelium from SCC or papilloma epithelium. In summary, we have confirmed that our infection model is an excellent platform to assess the impact of co-factors including tobacco carcinogens for oral PV cancerous progression. Our findings can assist in the design of novel prevention/treatment strategies for HPV positive vs. HPV negative disease.

Dynamics of papillomavirus in vivo disease formation & susceptibility to high-level disinfection-Implications for transmission in clinical settings

BACKGROUND

High-level disinfection protects tens-of-millions of patients from the transmission of viruses on reusable medical devices. The efficacy of high-level disinfectants for preventing human papillomavirus (HPV) transmission has been called into question by recent publications, which if true, would have significant public health implications.

METHODS

Evaluation of the clinical relevance of these published findings required the development of novel methods to quantify and compare: (i) Infectious titres of lab-produced, clinically-sourced, and animal-derived papillomaviruses, (ii) The papillomavirus dose responses in the newly developed in vitro and in vivo models, and the kinetics of in vivo disease formation, and (iii) The efficacy of high-level disinfectants in inactivating papillomaviruses in these systems.

FINDINGS

Clinical virus titres obtained from cervical lesions were comparable to those obtained from tissue (raft-culture) and in vivo models. A mouse tail infection model showed a clear dose-response for disease formation, that papillomaviruses remain stable and infective on fomite surfaces for at least 8 weeks without squames and up to a year with squames, and that there is a 10-fold drop in virus titre with transfer from a fomite surface to a new infection site. Disinfectants such as ortho-phthalaldehyde and hydrogen peroxide, but not ethanol, were highly effective at inactivating multiple HPV types in vitro and in vivo.

INTERPRETATION

Together with comparable results presented in a companion manuscript from an independent laboratory, this work demonstrates that high-level disinfectants inactivate HPV and highlights the need for standardized and well-controlled methods to assess HPV transmission and disinfection.

FUNDING

Advanced Sterilization Products, UK-MRC (MR/S024409/1 and MC-PC-13050) and Addenbrookes Charitable Trust.

Potential Effects of Human Papillomavirus Type Substitution, Superinfection Exclusion and Latency on the Efficacy of the Current L1 Prophylactic Vaccines

There are >200 different types of human papilloma virus (HPV) of which >51 infect genital epithelium, with ~14 of these classed as high-risk being more commonly associated with cervical cancer. During development of the disease, high-risk types have an increased tendency to develop a truncated non-replicative life cycle, whereas low-risk, non-cancer-associated HPV types are either asymptomatic or cause benign lesions completing their full replicative life cycle. HPVs can also be present as non-replicative so-called “latent” infections and they can also show superinfection exclusion, where cells with pre-existing infections with one type cannot be infected with a different HPV type. Thus, the HPV repertoire and replication status present in an individual can form a complex dynamic meta-community which changes with respect to both time and exposure to different HPV types. In light of these considerations, it is not clear how current prophylactic HPV vaccines will affect this system and the potential for iatrogenic outcomes is discussed in light of recent outcome data.

Human papillomavirus E6: Host cell receptor, GRP78, binding site prediction

Human papillomavirus (HPV) is the main cervical cancer-promoting element that is transmitted through sexual routes. Anal, head, and throat cancers are also reported to be accompanied by HPV infection. E6 is one of the HPV nonstructural proteins, which is responsible for cell differentiation by targeting tumor suppressor genes, p105Rb and p53. E6 was reported to be stabilized by two chaperone proteins; glucose-regulated protein 78 (GRP78) and heat shock protein 90. GRP78 is responsible for the unfolded protein response of the cells, and it was reported to be upregulated in many cancers, including cervical cancer. It was reported that knocking out GRP78 destabilizes E6 leading to faster degradation of E6 in vivo. The current work predicts the possible binding mode between E6 and GRP78 based on sequence and structural similarities.

Long-term protection of HPV test in women at risk of cervical cancer

Objective

To evaluate the 9-year incidence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and cumulative adherence to perform a next test in a cohort of women aged 40+ years with no cervical screening cytology within a window of 5 years (underscreened women), after baseline cervical cytology and HPV tests.

Methods

In Catalonia, Spain, co-testing with cytology and HPV test has been recommended in the Public Health system since 2006 for underscreened women. In 2007, 1,594 women with underscreened criteria were identified and followed through medical records form Pathological Department. 9-year cumulative incidence of histologically confirmed CIN2+ and cumulative adherence to perform a next test were estimated using Kaplan-Meier statistics.

Results

Follow-up was available for 1,009 women (63.3%) resulting in 23 women with. CIN2+ (2.3%). Of them, 4 women (17%) had both tests negative at baseline (3CIN2 and 1CIN3) with cumulative incidence of CIN2+ of 0.4% (95% CI: 0.1–1.4) at 5-years and 1.3% (95% CI: 0.4–3.7) at 9-years. During the first year, the prevalence among women with both tests positive was 27.0% (95% CI: 13.0–50.6) for CIN2+. Lost to follow-up was higher among women with both tests negative compared to those with both positive tests (38.7% vs 4.2%, p-value <0.001). 40.5% of the women HPV-/cyto- had a re-screening test during the 4 years following the baseline, increasing until 53.5% during the 6 years of follow-up.

Conclusions

HPV detection shows a high longitudinal predictive value at 9-year to identify women at risk to develop CIN2+. The data validate a safe extension of the 3-year screening intervals (current screening interval) to 5-year intervals in underscreened women that had negative HPV result at baseline. It is necessary to establish mechanisms to ensure screening participation and adequate follow-up for these women.

Expression of different L1 isoforms of Mastomys natalensis papillomavirus as mechanism to circumvent adaptive immunity

Although many high-risk mucosal and cutaneous human papillomaviruses (HPVs) theoretically have the potential to synthesize L1 isoforms differing in length, previous seroepidemiological studies only focused on the short L1 variants, co-assembling with L2 to infectious virions. Using the multimammate mouse Mastomys coucha as preclinical model, this is the first study demonstrating seroconversion against different L1 isoforms during the natural course of papillomavirus infection. Intriguingly, positivity with the cutaneous MnPV was accompanied by a strong seroresponse against a longer L1 isoform, but to our surprise, the raised antibodies were non-neutralizing. Only after a delay of around 4 months, protecting antibodies against the short L1 appeared, enabling the virus to successfully establish an infection. This argues for a novel humoral immune escape mechanism that may also have important implications on the interpretation of epidemiological data in terms of seropositivity and protection of PV infections in general.

Activation of DNA damage repair factors in HPV positive oropharyngeal cancers

The mechanisms regulating viral pathogenesis of human papillomavirus (HPV) associated oropharyngeal squamous cell cancers (OPSCC) are not well understood. In the cervix, activation of DNA damage repair pathways is critical for viral replication but little is known about their role in OPSCC. APOBEC factors have been shown to be increased in OPSCC but the significance of this is unclear. We therefore examined activation of DNA damage and APOBEC factors in HPV-induced OPSCC. Our studies show significantly increased levels of pCHK1, FANCD2, BRCA1, RAD51, pSMC1 and γH2AX foci in HPV-positive samples as compared to HPV-negative while the ATM effector kinase, pCHK2, was not increased. Similar differences were observed when the levels of proteins were examined in OPSCC cell lines. In contrast, the levels of APOBEC3B and 3A were found to be similar in both HPV-positive and -negative OPSCC. Our studies suggest members of ATR pathway and FANCD2 may be important in HPV-induced OPSCC.

YRNAs: New Insights and Potential Novel Approach in Head and Neck Squamous Cell Carcinoma

YRNAs are a class of non-coding RNAs that are components of the Ro60 ribonucleoprotein particle and are essential for initiation of DNA replication. Ro60 ribonucleoprotein particle is a target of autoimmune antibodies in patients suffering from systemic lupus erythematosus and Sjögren’s syndrome. Deregulation of YRNAs has been confirmed in many cancer types, but not in head and neck squamous cell carcinoma (HNSCC). The main aim of this study was to determine the biological role of YRNAs in HNSCC, the expression of YRNAs, and their usefulness as potential HNSCC biomarkers. Using quantitative reverse transcriptase (qRT)-PCR, the expression of YRNAs was measured in HNSCC cell lines, 20 matched cancer tissues, and 70 FFPETs (Formaline-Fixed Paraffin-Embedded Tissue) from HNSCC patients. Using TCGA (The Cancer Genome Atlas) data, an analysis of the expression levels of selected genes, and clinical-pathological parameters was performed. The expression of low and high YRNA1 expressed groups were analysed using gene set enrichment analysis (GSEA). YRNA1 and YRNA5 are significantly downregulated in HNSCC cell lines. YRNA1 was found to be significantly downregulated in patients’ tumour sample. YRNAs were significantly upregulated in T4 stage. YRNA1 showed the highest sensitivity, allowing to distinguish healthy from cancer tissue. An analysis of TCGA data revealed that expression of YRNA1 was significantly altered in the human papilloma virus (HPV) infection status. Patients with medium or high expression of YRNA1 showed better survival outcomes. It was noted that genes correlated with YRNA1 were associated with various processes occurring during cancerogenesis. The GSEA analysis showed high expression enrichment in eight vital processes for cancer development. YRNA1 influence patients’ survival and could be used as an HNSCC biomarker. YRNA1 seems to be a good potential biomarker for HNSCC, however, more studies must be performed and these observations should be verified using an in vitro model.

Human Papillomavirus 58 E7 T20I/G63S Variant Isolated from an East Asian Population Possesses High Oncogenicity

Human papillomavirus (HPV) type 58 is the third most commonly detected HPV type in cervical cancer among Eastern Asians. Our previous international epidemiological studies revealed that HPV58 carrying an E7 natural variant, T20I/G63S (designated V1), was associated with a higher risk of cervical cancer. We recently showed that V1 possesses a greater ability to immortalize and transform primary cells, as well as degrading pRB more effectively, than the prototype and other common variants. In this study, we performed a series of phenotypic and molecular assays using physiologically relevant in vitro and in vivo models to compare the oncogenicity of V1 with that of the prototype and other common natural variants. Through activation of the AKT and K-Ras/extracellular signal-regulated kinase (ERK) signaling pathways, V1 consistently showed greater oncogenicity than the prototype and other variants, as demonstrated by increased cell proliferation, migration, and invasion, as well as induction of larger tumors in athymic nude mice. This study complements our previous epidemiological and molecular observations pinpointing the higher oncogenicity of V1 than that of the prototype and all other common variants. Since V1 is more commonly found in eastern Asia, our report provides insight into the design of HPV screening assays and selection of components for HPV vaccines in this region.IMPORTANCE Epidemiological studies have revealed that a wild-type variant of HPV58 carrying an E7 variation, T20I/G63S (V1), is associated with a higher risk of cervical cancer. We previously reported that this increased oncogenicity could be the result of the virus's greater ability to degrade pRB, thereby leading to an increased ability to grow in an anchorage-independent manner. In addition to this, this report further showed that this HPV variant induced activation of the AKT and K-Ras/ERK signaling pathways, thereby explaining its genuine oncogenicity in promoting cell proliferation, migration, invasion, and formation of tumors, all to a greater extent than the prototype HPV58 and other common variants.

Is Human Papillomavirus and Helicobacter pylori Related in Gastric Lesions?

BACKGROUND

Human papillomavirus (HPV), the causative agent of cervical cancer, is also suggested as a risk factor for gastric adenocarcinoma. Many infectious agents besides Helicobacter pylori have been associated with gastritis. The aim of this study was to investigate HPV DNA and genotyping HPV type 16 DNA in gastric adenocarcinoma and Helicobacter pylori gastritis cases.

METHODS

A hundred and six gastric adenocarcinoma and Helicobacter pylori gastritis samples and 26 controls were included. After deparaffinization by xylene, DNA extraction was performed by the phenol-chloroform-isoamyl alcohol method and 106 samples were studied with a G6PDH control kit (Eurogentec, Seraing, Belgium). Fifty-three adenocarcinoma and 43 Helicobacter pylori samples were thought to have enough tissue and were studied for HPV DNA. HPV types other than 16 and HPV type 16 DNA were detected by Real Time PCR using the L1 region. Amplifications of MY09/11 products were done by GP5+/GP6+ primers and Cyanine-5 labeled HPV DNA and HPV 16 DNA specific probe in Light Cycler 2.0 (Roche Diagnostics, Germany) device.

RESULTS

Among gastric adenocarcinoma and Helicobacter pylori gastritis samples, 20/53 (38%) and 18/43 (41.8%) were HPV DNA positive, respectively. Five (19.2%) of 26 controls were HPV DNA positive.

CONCLUSIONS

Our 38% positive result in the gastric carcinoma group is in concordance with previous reports. This is the first study revealing the HPV-H. pylori relationship in gastritis cases and we concluded that with regard to the nearly three-fold higher HPV DNA (41.8%) in gastritis cases compared to controls, Helicobacter pylori positive cases should also be evaluated in favor of HPV in the gastritis group.

CD8 infiltration is associated with disease control and tobacco exposure in intermediate-risk oropharyngeal cancer

Oropharyngeal squamous cell carcinoma (OPSCC) incidence is increasing at a nearly epidemic rate, largely driven by the human papillomavirus (HPV). Despite the generally favorable clinical outcomes of patients with HPV driven (HPV+) OPSCC, a significant subset of HPV tumors associated with tobacco exposure have diminished treatment response and worse survival. The tumor immune microenvironment (TIME) has been shown to be a critical driver of treatment response and oncologic outcomes in OPSCC generally and HPV+ OPSCC more specifically. However, the impact of tobacco exposure on the TIME in OPSCC patients remains unclear. We analyzed the relationship between TIME, tobacco exposure and clinical outcomes in OPSCC patients (n = 143) with extensive tobacco exposure (median pack-years = 40). P16 overexpression, a surrogate marker of HPV association, was a strong predictor of relapse-free (RFS) and overall survival (OS) (p < 0.001, p < 0.001 respectively) regardless of tobacco exposure and associated strongly with differential infiltration of the tumor by both CD3 and CD8 lymphocytes measured via immunohistochemistry (p < 001, p < 0.001 respectively). CD3 and CD8 infiltration was a strong predictor of RFS and OS and associated strongly with disease stage (AJCC 8th Edition Staging Manual). Tobacco exposure correlated significantly (p < 0.001) with decreased CD8 infiltration in p16+ OPSCC tumors. Our findings demonstrate that the HPV+ OPSCC clinical outcomes are strongly correlated with the TIME, which is potentially modulated by tobacco exposure. Immunomodulatory strategies targeting this disease in smokers must take into consideration the potential modifying effects of tobacco exposure on treatment effectiveness and clinical outcomes.

IFI16 promotes cervical cancer progression by upregulating PD-L1 in immunomicroenvironment through STING-TBK1-NF-kB pathway

Cervical cancer remains one of the leading causes of cancer death worldwide. Immunotherapy is the most promising cancer therapeutics in recent years and has gain positive results in several cancers in the clinic. This study was aimed to investigate the roles and mechanism of IFI16 in cervical cancer immunotherapy. We observed an abnormally high expression of Programmed cell death 1 ligand 1 (PD-L1) and Interferon-inducible 16 (IFI16) in Human papillomavirus (HPV) positive cervical cancer cells compared with HPV negative cervical cancer cells. Moreover, IFI16 promotes cervical cancer development in vitro and in vivo as the oncogenic role of PD-L1. In the subsequent mechanism investigation, we found that IFI16 activated STING-TBK1-mediated immunoregulation, and subsequently activated downstream NF-kB pathway, which interacted with the proximal region of PD-L1 promoter to facilitate PD-L1 expression. In conclusion, we found that IFI16 positively regulate PD-L1 through STING-TBK1-NF-kB pathway, thus promoting cervical cancer progression. The roles of IFI16 in cervical cancer progression deserve further investigation and hold the promise of being developed as a novel immunotherapy target in the future.

ADAR1 function affects HPV replication and is associated to recurrent human papillomavirus-induced dysplasia in HIV coinfected individuals

Infection by human papillomavirus (HPV) alters the microenvironment of keratinocytes as a mechanism to evade the immune system. A-to-I editing by ADAR1 has been reported to regulate innate immunity in response to viral infections. Here, we evaluated the role of ADAR1 in HPV infection in vitro and in vivo. Innate immune activation was characterized in human keratinocyte cell lines constitutively infected or not with HPV. ADAR1 knockdown induced an innate immune response through enhanced expression of RIG-I-like receptors (RLR) signaling cascade, over-production of type-I IFNs and pro-inflammatory cytokines. ADAR1 knockdown enhanced expression of HPV proteins, a process dependent on innate immune function as no A-to-I editing could be identified in HPV transcripts. A genetic association study was performed in a cohort of HPV/HIV infected individuals followed for a median of 6 years (range 0.1-24). We identified the low frequency haplotype AACCAT significantly associated with recurrent HPV dysplasia, suggesting a role of ADAR1 in the outcome of HPV infection in HIV+ individuals. In summary, our results suggest that ADAR1-mediated innate immune activation may influence HPV disease outcome, therefore indicating that modification of innate immune effectors regulated by ADAR1 could be a therapeutic strategy against HPV infection.

Positivity and prevalence of human papillomavirus among a large population of women in southeastern China

Objective

To formulate strategies for prevention of cervical cancer, we investigated the prevalence of human papillomavirus (HPV) infection and the age-specific distribution among female participants in southeastern China.

Methods

From January 2016 to July 2018, 36,871 women from Meizhou People’s Hospital (Huangtang Hospital), Meizhou Hospital Affiliated to Sun Yat-sen University were enrolled in this prospective study. HPV genotypes were detected using Luminex technology.

Results

HPV infection was observed in 18.34% of the participants, and 79.98% were infected with high-risk HPVs. The five most prevalent genotypes were HPV52 (18.18%), HPV16 (16.06%), HPV58 (11.37%), HPV53 (8.82%), and HPV39 (6.42%). The 9-valent HPV vaccine efficiently reduced the HPV infection rate by more than 10%, which is twofold the rate of other vaccines. Most HPV infections were observed in women age 40 to 49 years, and those age 30 to 59 years accounted for 79.62% of positive patients.

Conclusion

Our findings regarding HPV genotypes and the age-specific distribution of HPV infection in the study area will contribute to the development of cervical cancer screening programs and vaccine strategies.

Untangling the dynamics of persistence and colonization in microbial communities

A central goal of community ecology is to infer biotic interactions from observed distributions of co-occurring species. Evidence for biotic interactions, however, can be obscured by shared environmental requirements, posing a challenge for statistical inference. Here, we introduce a dynamic statistical model, based on probit regression, that quantifies the effects of spatial and temporal covariance in longitudinal co-occurrence data. We separate the fixed pairwise effects of species occurrences on persistence and colonization rates, a potential signal of direct interactions, from latent pairwise correlations in occurrence, a potential signal of shared environmental responses. We first validate our modeling framework with several simulation studies. Then, we apply the approach to a pressing epidemiological question by examining how human papillomavirus (HPV) types coexist. Our results suggest that while HPV types respond similarly to common host traits, direct interactions are sparse and weak, so that HPV type diversity depends largely on shared environmental drivers. Our modeling approach is widely applicable to microbial communities and provides valuable insights that should lead to more directed hypothesis testing and mechanistic modeling.

Differential phosphorylation determines the repressor and activator potencies of GLI1 proteins and their efficiency in modulating the HPV life cycle

The Sonic Hedgehog (Shh) signalling pathway plays multiple roles during embryonic development and under pathological conditions. Although the core components of the Shh pathway are conserved, the regulation of signal transduction varies significantly among species and cell types. Protein kinases Ulk3 and Pka are involved in the Shh pathway as modulators of the activities of Gli transcription factors, which are the nuclear mediators of the signal. Here, we investigate the regulation and activities of two GLI1 isoforms, full-length GLI1 (GLI1FL) and GLI1ΔN. The latter protein lacks the first 128 amino acids including the conserved phosphorylation cluster and the binding motif for SUFU, the key regulator of GLI activity. Both GLI1 isoforms are co-expressed in all human cell lines analysed and possess similar DNA binding activity. ULK3 potentiates the transcriptional activity of both GLI1 proteins, whereas PKA inhibits the activity of GLI1ΔN, but not GLI1FL. In addition to its well-established role as a transcriptional activator, GLI1FL acts as a repressor by inhibiting transcription from the early promoters of human papillomavirus type 18 (HPV18). Additionally, compared to GLI1ΔN, GLI1FL is a more potent suppressor of replication of several HPV types. Altogether, our data show that the N-terminal part of GLI1FL is crucial for the realization of its full potential as a transcriptional regulator.

Gene Expression Profiling of MicroRNAs in HPV-Induced Warts and Normal Skin

: Infection with the human papillomavirus (HPV) is a common occurrence among the global population, with millions of new cases emerging on an annual basis. Dysregulated microRNA (miRNA) expression is increasingly being identified to play a role in a number of different diseases, especially in the context of high-risk HPV infection. The present study investigated the miRNA expression profiles of warts induced by low-risk HPV. In warts, miR-27b, miR-24-1, miR-3654, miR-647, and miR-1914 were downregulated while miR-612 was upregulated compared to normal skin. Using miRTargetLink Human, experimentally supported evidence was obtained showing that miR-27b targeted the vascular endothelial growth factor C (VEGFC) and CAMP-responsive element binding protein 1 (CREB1) genes. The VEGFC and CREB1 genes have been reported to be involved in tumorigenesis and wart formation, respectively. Similarly, the oxidized low-density lipoprotein receptor 1 (OLR1) gene, which plays an important role in the humoral immunity of the skin, and the plexin D1 (PLXND1) gene, which is highly expressed in tumor vasculature, were both found to be common targets of miR-27b, miR-1914, and miR-612.

HPV infection and the genital cytokine milieu in women at high risk of HIV acquisition

Human papillomavirus (HPV) infection correlates with higher rates of HIV acquisition, but the underlying biological mechanisms are unclear. Here we study associations between HPV and HIV acquisition and relate these to vaginal cytokine profiles in an observational cohort of women at high risk of HIV infection (CAPRISA 004, n = 779) and with 74% HPV prevalence. We report here that HPV infection associates with a 2.5-fold increase in HIV acquisition risk in this population (95% CI: 1.2-5.3). Among 48 vaginal cytokines profiled, cytokines associated with HPV infection overlap substantially with cytokines associated with HIV risk, but are distinct from those observed in HPV negative women. Although our data do not establish a causative link between HPV status and the risk of HIV, we suggest that increasing HPV vaccination coverage may carry an additional benefit of reducing the risk of contracting HIV infection, particularly in regions with high HPV prevalence.

Recent advances in invasive adenocarcinoma of the cervix

Endocervical adenocarcinomas (ECAs) are currently classified according to the 2014 World Health Organization (WHO) system, which is predominantly based on descriptive morphologic characteristics, considers factors bearing minimal etiological, clinical, or therapeutic relevance, and lacks sufficient reproducibility. The 2017 International Endocervical Adenocarcinoma Criteria and Classification (IECC) system was developed by a group of international collaborators to address these limitations. The IECC system separates ECAs into two major groups-those that are human papillomavirus-associated (HPVA) and those that are non-HPV-associated (NHPVA)-based on morphology (linked to etiology) alone, precluding the need for an expensive panel of immunohistochemical markers for most cases. The major types of HPVA ECA include the usual (with villoglandular and micropapillary architectural variants) and mucinous types (not otherwise specified [NOS], intestinal, signet-ring, and invasive stratified mucin-producing carcinoma). Invasive adenocarcinoma NOS is morphologically uninformative, yet considered part of this group when HPV positive. NHPVA ECAs include gastric, clear cell, endometrioid, and mesonephric types. The IECC system is supported by demographic and clinical features (HPVA ECAs develop in younger patients, are smaller, and are diagnosed at an earlier stage), p16/HPV status (almost all HPVA ECAs are p16 and/or HPV positive), prognostic parameters (NHPVA ECAs more often have lymphovascular invasion, lymph node metastases, and are Silva pattern C), and survival data (NHPVA ECAs are associated with worse survival). A move from the morphology-based WHO system to the IECC system will likely provide clinicians with an improved means to diagnose and classify ECAs, and ultimately, to better personalize treatment for these patients.

Carbon-ion irradiation overcomes HPV-integration/E2 gene-disruption induced radioresistance of cervical keratinocytes

To date, only few data exist on mechanisms underlying the human papillomavirus (HPV)-associated irradiation response. It has been suggested, that the viral E2 gene plays an important role in that context. The aim of the current study is to compare the effect of photon- and carbon-ion (12C)-radiation therapy (RT) on cells with different HPV and E2 gene status. We hypothesized that 12C-RT might overcome the radioresistance of E2 gene-disrupted cells. We analyzed four different cell lines that differed in HPV status or E2 gene status. Cells were irradiated with either photons or 12C. Clonogenic survival, cell cycle and expression of Rb and p53 were analyzed. Radiosensitivity seemed to be dependent on E2 gene status and type of RT. 12C-RT led to lower surviving fractions, indicating higher radiosensitivity even in cells with disrupted E2 gene. The observed relative biological effectiveness (RBE) of 12C-RT for C33a/Caski and W12/S12 was 1.3/4 and 2.7/2.5, respectively. Cell cycle regulation after both photon- and 12C-RT was dependent on HPV status and on E2 gene status. Furthermore, the effect of RT on expression of p53 and Rb seemed to be dependent on E2 gene status and type of RT. We showed that 12C-RT overcomes HPV-integration induced radioresistance. The effect of RT on cell cycle regulation as well as on expression of p53 and Rb seemed to be dependent on HPV status, E2 gene status and type of RT. Differences in Rb expression and cell cycle regulation may play a role for enhanced radiosensitivity to 12C-RT of cells with disrupted E2 gene.

Patient factors affecting successful linkage to treatment in a cervical cancer prevention program in Kenya: A prospective cohort study

Objective

To identify patient factors associated with whether women who screened positive for high-risk human papillomavirus (hrHPV) successfully accessed treatment in a cervical cancer prevention program in Kenya.

Methods

A prospective cohort study was conducted as part of a trial of implementation strategies for hrHPV-based cervical cancer screening in western Kenya from January 2018 to February 2019. In this larger trial, women underwent hrHPV testing during community health campaigns (CHCs), and hrHPV+ women were referred to government facilities for cryotherapy. For this analysis, we looked at rates of and predictors of presenting for treatment and presenting within 30 days of receiving positive hrHPV results (“timely” presentation). Data came from questionnaires completed at the time of screening and treatment. Multivariable logistic regression was used to identify factors associated with each outcome.

Results

Of the 505 hrHPV+ women, 266 (53%) presented for treatment. Cryotherapy was performed in 236 (89%) of the women who presented, while 30 (11%) were not treated: 15 (6%) due to gas outage, six (2%) due to pregnancy, five (2%) due to concern for cervical cancer, and four (2%) due to an unknown or other reason. After adjusting for other factors in the multivariable analysis, higher education level and missing work to come to the CHC were associated with presenting for treatment. Variables that were associated with increased likelihood of timely presentation were missing work to come to the CHC, absence of depressive symptoms, told by someone important to come to the CHC, and shorter distance to the treatment site.

Conclusion

The majority of hrHPV+ women who did not get treated were lost at the stage of decision-making or accessing treatment, with a small number encountering barriers at the treatment sites. Patient education and financial support are potential areas for intervention to increase rates of hrHPV+ women seeking treatment.

The association of integration patterns of human papilloma virus and single nucleotide polymorphisms on immune- or DNA repair-related genes in cervical cancer patients

The present study investigated the association between single nucleotide polymorphisms (SNPs) in immune- or DNA repair-related genes and the integration pattern of human papillomavirus (HPV), a promising prognostic marker in cervical cancer. The HPV integration patterns of cervical cancer patients were determined by polymerase chain reaction and in situ hybridization, and categorized as episomal (group A), single-copy or multi-copy tandem repetition integrated (group B), and undetectable HPV types (group C). After sample and SNP quality control, 166,505 SNPs in 161 samples (38, 111, and 12 patients in groups A, B, and C, respectively) were examined. None of the SNPs reached genome-wide significance, and several candidate SNPs for future study were selected, including rs10999435 on chromosome 10q22, rs1322054 on chromosome 9q32-33, and rs10902171 on chromosome 11p15. Luciferase assay identified rs1322054 as the primary functional variant to regulate gene expression in immune cell. Further studies are needed to determine the genetic background of different integration patterns of HPV in cervical cancer patients.

Comparison of a Newly Developed HPV Genotyping Assay (Mojin HPV Kit) with Cobas 4800 HPV Test for Detection of High-Risk HPV in Specimens Collected in SurePath Solution

BACKGROUND

Human papillomavirus (HPV) detection based on cervical cytology specimens is useful for cervical cancer screening. The aim of this study was to compare Mojin HPV kit (a newly developed HPV genotyping assay) with the Cobas 4800 HPV test in detecting high-risk (HR) HPV.

METHODS

A total of 347 cervical exfoliated cell specimens were tested using the Mojin HPV kit and Cobas 4800 HPV test. When the results from the two tests were inconsistent, gene sequencing was performed for correction.

RESULTS

For HR-HPV, the results of the two assays agreed by 96.3% [Kappa = 0.911; 95% confidence interval (CI): 0.863 - 0.958)]. The positive and negative coincidence rates between the two tests were 96.0% (95% CI: 92.7% - 98.0%) and 97.0% (95% CI: 91.5% - 99.4%), respectively. Of the 13 samples with discordant results, 3 samples were false positive and 10 samples were true negative for Mojin HPV test, according to the identification by sequencing. For HPV16 genotyping, the total coincidence rate between the 2 tests was 100% (Kappa = 1.000), and 99.7% (Kappa = 0.973; 95% CI: 0.905 - 1.000) for HPV18.

CONCLUSIONS

Mojin HPV kit may be as effective as Cobas 4800 HPV assay in detecting the total HR-HPV, especially HPV16 or HPV18.

Label-free cervicovaginal fluid proteome profiling reflects the cervix neoplastic transformation

Cervicovaginal fluid (CVF) is a valuable source of clinical information about the female reproductive tract in both nonpregnant and pregnant women. The aim of this study is to specify the CVF proteome at different stages of cervix neoplastic transformation by label-free quantitation approach based on liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The proteome composition of CVF from 40 women of reproductive age with human papillomavirus (HPV)-associated cervix neoplastic transformation (low-grade squamous intraepithelial lesion [LSIL], high-grade squamous intraepithelial lesion [HSIL], and CANCER) was investigated. Hierarchical clustering and principal component analysis (PCA) of the proteomic data obtained by a label-free quantitation approach show the distribution of the sample set between four major clusters (no intraepithelial lesion or malignancy [NILM], LSIL, HSIL and CANCER) depending on the form of cervical lesion. Multisample ANOVA with subsequent Welch's t test resulted in 117 that changed significantly across the four clinical stages, including 27 proteins significantly changed in cervical cancer. Some of them were indicated as promising biomarkers previously (ACTN4, VTN, ANXA1, CAP1, ANXA2, and MUC5B). CVF proteomic data from the discovery stage were analyzed by the partial least squares-discriminant analysis (PLS-DA) method to build a statistical model, allowing to differentiate severe dysplasia (HSIL and CANCER) from the mild/normal stage (NILM and LSIL), and receiver operating characteristic (ROC) area under the curve (AUC) were obtained on an independent set of 33 samples. The sensitivity of the model was 77%, and the specificity was 94%; AUC was equal to 0.87. CVF proteome proved to be reflect the stage of cervical epithelium neoplastic process.

Endocervical adenocarcinoma in situ (AIS) with ovarian and pulmonary involvement: report of a case and review of the literature suggesting a "seed and soil hypothesis"

PURPOSE

Cervical cancer metastases to the ovary may occur with advanced tumor stage, deep cervical stromal involvement and corpus involvement. Endocervical adenocarcinoma in situ (AIS) with ovarian involvement is exceptionally rare with about twelve reported cases.

METHODS

Here we present a case of endocervical AIS with ovarian and pulmonary involvement 39 months after the initial diagnosis. The characteristics of that case were compared and summarized with the eleven previously published cases.

RESULTS

The patients' age ranged between 30 and 40 years (median 37.4 years). The time interval between the diagnosis of AIS and ovarian involvement was 26.7 months (range 2-84 months). Majority of the patients are alive without evidence of disease after a median time of 63.4 months (range 9-156 months). All reported cases were positive for high-risk HPV which was associated with strong p16 expression on immunohistochemistry.

CONCLUSIONS

The ovarian involvement by endocervical AIS suggests the concept of a transtubal spread of the neoplastic cervical cells with or without previous colonization within the endometrium without evidence of invasive growth, suggesting a seed and soil spread of the disease. In cases with ovarian involvement by the AIS and without additional extragenital spread, the prognosis may be favorable.

How non-enveloped viruses hijack host machineries to cause infection

Viruses must navigate the complex endomembranous network of the host cell to cause infection. In the case of a non-enveloped virus that lacks a surrounding lipid bilayer, endocytic uptake from the plasma membrane is not sufficient to cause infection. Instead, the virus must travel within organelle membranes to reach a specific cellular destination that supports exposure or arrival of the virus to the cytosol. This is achieved by viral penetration across a host endomembrane, ultimately enabling entry of the virus into the nucleus to initiate infection. In this review, we discuss the entry mechanisms of three distinct non-enveloped DNA viruses-adenovirus (AdV), human papillomavirus (HPV), and polyomavirus (PyV)-highlighting how each exploit different intracellular transport machineries and membrane penetration apparatus associated with the endosome, Golgi, and endoplasmic reticulum (ER) membrane systems to infect a host cell. These processes not only illuminate a highly-coordinated interplay between non-enveloped viruses and their host, but may provide new strategies to combat non-enveloped virus-induced diseases.

Human Papilloma Virus-Associated Cervical Cancer and Health Disparities

Cervical cancer develops through persistent infection with high-risk human papilloma virus (hrHPV) and is a leading cause of death among women worldwide and in the United States. Periodic surveillance through hrHPV and Pap smear-based testing has remarkably reduced cervical cancer incidence worldwide and in the USA. However, considerable discordance in the occurrence and outcome of cervical cancer in various populations exists. Lack of adequate health insurance appears to act as a major socioeconomic burden for obtaining cervical cancer preventive screening in a timely manner, which results in disparate cervical cancer incidence. On the other hand, cervical cancer is aggressive and often detected in advanced stages, including African American and Hispanic/Latina women. In this context, our knowledge of the underlying molecular mechanism and genetic basis behind the disparate cervical cancer outcome is limited. In this review, we shed light on our current understanding and knowledge of racially disparate outcomes in cervical cancer.

HPV-based screening for cervical cancer among women 55-59 years of age

AIM

Many cervical cancers occurs among women over 65 and prevalence of HPV genotypes in this age cohort is sparingly studied. One aim of this study was to study the prevalence and distribution of HPV genotypes in women 55-59 years, with normal cytology when exiting the screening program. Secondly, HPV clearance as well as the value of HPV genotyping and/or liquid based cytology as triage tests for identifying histological dysplasia among women with persistent HPV was studied.

METHODS

Women that exited the screening program with normal cytology, between the years 2012-2014, in Örebro County, Sweden, were invited to this study. A total of 2946 samples were analyzed with a broad-spectrum assay to detect both hrHPV and lrHPV in order to investigate the distribution of genotypes. In the consent group, women with a positive hrHPV test were offered a follow-up test and a cone biopsy for histological confirmation, and a follow up sample 6 months post cone.

RESULTS

The overall prevalence of hrHPV was 7.4% and 59% of them remained hrHPV positive in a follow-up test after 12 months. A total of 99 women had a cone biopsy done, where 19% showed histological dysplasia. HPV 53 was the most common genotype, and among women with histology confirmed LSIL or HSIL, HPV 31 was most common. A positive hrHPV result showed a PPV of 25% for LSIL+ and 12.5%for HSIL+. Using detection of HPV 16/18 genotypes as a triage test for hrHPV positive tests, indicated FNR for histological LSIL+ and HSIL+ of 94% and 87.5% respectively, whilst triage based on cervical cytology had a FNR of 69% for LSIL+ and 37.5% for HSIL+.

CONCLUSION

The most common hrHPV genotypes among women 55-59 years of age were non HPV16/18 genotypes, and in this population, these genotypes represented most of the histological verified HSIL lesions. This result does not support the proposition of a HPV 16/18 triaging test after a positive hrHPV test as a marker of histological HSIL+ cervical lesions in women over 55 years of age. Similarly, cytological triage after a positive hrHPV showed no additional benefit in this population. Specific triaging tests should be validated to follow post-menopausal women with a positive hrHPV test.

Composite Analysis of the Virome and Bacteriome of HIV/HPV Co-Infected Women Reveals Proxies for Immunodeficiency

The human cervical microbiome is complex, and its role in health and disease has just begun to be elucidated. In this study, 57 cervical swab samples from 19 HIV/HPV co-infected women were analyzed for both virome and bacteriome composition. Virome analysis focused on circular DNA viruses through rolling circle amplification followed by next-generation sequencing (NGS). Data were assigned to virus families and genera, and HPV types were identified. NGS data of bacterial 16S from a subset of 24 samples were assigned to operational taxonomic units and classified according to vaginal microbiome community state types (CSTs). Four viral families were found: Papillomaviridae, Anelloviridae, Genomoviridae, and Herpesviridae. Papillomavirus reads were more abundant in women with premalignant cervical lesions, which were also strongly associated with multiple (≥3) high-risk HPV infection. Anellovirus read abundance was negatively correlated with host CD4+ T-cell counts. The bacteriome revealed the presence of CST III and CST IV, and women with ≥1% frequency of genomovirus or herpesvirus reads displayed an increased risk of carrying CST IV. By characterizing the composition of the cervical circular DNA viruses and the bacteriome of HIV/HPV co-infected women, we identified putative interactions between these two microorganism communities and their associations with patients’ clinical characteristics, notably immunodeficiency status.

5-aminolevulinic acid photodynamic therapy reduces HPV viral load via autophagy and apoptosis by modulating Ras/Raf/MEK/ERK and PI3K/AKT pathways in HeLa cells

Human papillomavirus (HPV) infection is linked to several diseases, the most prominent of which are cervical cancer and genital condyloma acuminatum. Previous studies have suggested an effective role for 5-aminolevulinic acid photodynamic therapy (ALA-PDT) against various cancers by the induction of autophagy and apoptosis. However, few reports have focused on the effectiveness of ALA-PDT on HPV related disorders. To identify the role of ALA-PDT in the context of HPV infection, we initially investigated 111 patients suffering from genital condyloma acuminatum. HPV viral load detected before and after ALA-PDT treatment was compared during this procedure; a significant difference was noted. HeLa (HPV18) cells were exposed to ALA-PDT in vitro to further explore the underlying mechanisms. Western blot analysis showed that ALA-PDT induces LC3II and p62 expression, along with the up regulation of caspase-3 and cleaved caspase-3. Our study also demonstrated that ALA-PDT treatment inhibits the proliferation of HeLa cells in a dose dependent manner and effectively reduces HPV viral load via autophagy and apoptosis by regulating the Ras/Raf/MEK/ERK and PI3K/AKT/mTOR pathways. Hydroxychloroquine (HCQ), although it inhibited autophagy degradation, functioned to activate reactive oxygen species (ROS) levels of ALA-PDT to enhance the observed effect. These findings suggest strategies for the improvement of PDT efficacy in patients.

The APOBEC3 genes and their role in cancer: insights from human papillomavirus

The interaction between human papillomaviruses (HPV) and the apolipoprotein-B mRNA-editing catalytic polypeptide-like (APOBEC)3 (A3) genes has garnered increasing attention in recent years, with considerable efforts focused on understanding their apparent roles in both viral editing and in HPV-driven carcinogenesis. Here, we review these developments and highlight several outstanding questions in the field. We consider whether editing of the virus and mutagenesis of the host are linked or whether both are essentially separate events, coincidentally mediated by a common or distinct A3 enzymes. We discuss the viral mechanisms and cellular signalling pathways implicated in A3 induction in virally infected cells and examine which of the A3 enzymes might play the major role in HPV-associated carcinogenesis and in the development of therapeutic resistance. We consider the parallels between A3 induction in HPV-infected cells and what might be causing aberrant A3 activity in HPV-independent cancers such as those arising in the bladder, lung and breast. Finally, we discuss the implications of ongoing A3 activity in tumours under treatment and the therapeutic opportunities that this may present.