Sexually Transmitted Human Papillomavirus: Update in Epidemiology, Prevention, and Management.

This review presents the epidemiology, pathophysiology, prevention, and management of sexually transmitted human papillomavirus (HPV) and its associated diseases. HPV is the most common sexually transmitted infection worldwide. Prevalence varies regionally. Low-risk strains cause anogenital warts, which can be managed with patient- or provider-applied therapies. High-risk strains cause lower anogenital cancers. Primary and secondary prevention strategies include vaccination and screening for precancerous lesions, respectively. Management of abnormal screening results vary by test result, anatomic site, and individual cancer risk. Approaches include close rescreening, high-resolution visualization with biopsy, and-when biopsy-proven precancer is identified-removal or destruction of the lesion.

hTERT and IGF-1R Proteins Expression in Response to Treatment in Patients with HPV Alpha 9-Positive Cervical Cancer.

Human papillomavirus (HPV) infection is strongly associated with cervical cancer (CC). Genomic alterations caused by viral infection and subsequent dysregulation of cellular metabolism under hypoxic conditions could influence the response to treatment. We studied a possible influence of IGF-1Rb, hTERT, HIF1a, GLUT1 protein expression, HPV species presence and relevant clinical parameters on the response to treatment. In 21 patients, HPV infection and protein expression were detected using GP5+/GP6+PCR-RLB and immunohistochemistry, respectively. The worse response was associated with radiotherapy alone compared with chemoradiotherapy (CTX-RT), anemia and HIF1a expression. HPV16 type was the most frequent (57.1%) followed by HPV-58 (14.2%) and HPV-56 (9.5%). The HPV alpha 9 species was the most frequent (76.1%) followed by alpha 6 and alpha 7. IGF-1Rb (85.7%), HIF1a (61.9%), GLUT1 (52.3%), and hTERT expression [cytoplasm and nucleus (90.4%)] were detected. The MCA factorial map showed different relationships, standing out, expression of hTERT and alpha 9 species HPV, expression of hTERT and IGF-1Rb expression [Fisher's exact test (P = 0.04)]. A slight trend of association was observed between, GLUT1 and HIF1 a expression, hTERT and GLUT1 expression. A noteworthy finding was the subcellular localization of hTERT in the nucleus and cytoplasm of CC cells and its possible interaction with IGF-1R in presence of HPV alpha 9 species. Our findings suggest that the expression of HIF1a, hTERT, IGF-1Rb and GLUT1 proteins that interact with some HPV species may contribute to cervical cancer development, and the modu lation of treatment response.

Human papillomavirus associated XPF deficiency increases alternative end joining and cisplatin sensitivity in head and neck squamous cell carcinoma.

OBJECTIVES: Human papillomavirus (HPV) positive head and neck squamous cell carcinoma (HNSCC) showed a considerably better prognosis with greater cisplatin sensitivity compared to their HPV-negative counterparts. Deciphering the underlying molecular mechanisms for HPV-induced cisplatin sensitivity is imperative to improve the prognosis of HPV-negative HNSCC. MATERIALS AND METHODS: The Fanconi anemia (FA) pathway status in HNSCC cells was analysed by detecting the cell cycle and chromosomal aberrations. XPF expression was validated using PCR, western blot, and immunohistochemistry. Droplet digital PCR and GFP expressing reporter assay were used to analyse the changes in alternative end-joining (alt-EJ) levels. The cisplatin sensitization was verified by cell proliferation assay, clonogenic cell survival assay, and TUNEL. RESULTS: HPV-positive HNSCC cells showed significant prolonged G2-M cell cycle arrest and aberrant chromosome formation under interstrand crosslinker treatment. Both mRNA and protein expression of XPF were considerably decreased in HPV-positive HNSCC, according to the analysis of cellular and clinical data. XPF inhibition upregulated the activity of the alt-EJ pathway in HPV-negative HNSCC cells by 32.02% (P < 0.001) but had little effect on HPV-positive HNSCC. Consistent with this, simultaneous suppression of XPF and alt-EJ enhanced cisplatin sensitivity of HPV-negative HNSCC in vitro and in vivo. CONCLUSION: HPV-positive HNSCC cells exhibit a profound FA pathway deficiency associated with reduced XPF expression. HNSCC cells with compromised XPF function are more reliant on the alt-EJ pathway for genomic stability. Combining FA and alt-EJ inhibition may be used to cope with the hard-to-treat HPV-negative HNSCC.

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.

Special Issue: HPV and HPV Vaccines.

Our fundamental understanding of papillomaviruses and their interactions with their host, including their role in cancer and how the immune system responds to them, has made the elimination of cervical cancer a realistic global health goal [...].

Combination of IDO1high and CCL19low expression in the tumor tissue reduces survival in HPV positive cervical cancer.

The over expression of Indoleamine 2, 3-Dioxygenase (IDO1), an immune checkpoint inhibitor, is well known in cervical cancer. However, its association with chemokine signals promoting cellular infiltration in the cervical tumor microenvironment, is unknown. In the current study, we evaluated the expression and enzymatic activity of IDO1. We also profiled the expression of chemokine ligand-receptors- CCR4-CCL22, CXCR3-CXCL10, CXCR4-CXCL12, and CCR7-CCL19 using immunohistochemistry (IHC), and studied their association with IDO1, statistically. After getting an informed consent, punch biopsy samples were obtained from 105 patients diagnosed with cervical cancer. HPV typing by Sanger sequencing, realtime PCR for quantifying IDO1 mRNA expression, HPLC for determining the K/T ratio and IHC for all the above chemokine receptor-ligand pairs along with IDO1 were performed. We found a significant increase in the expression of IDO1 and K/T levels in early and locally advanced stages when compared to Stage IV disease. Among the chemokine ligand -receptor pairs profiled, we found that high CCL19 marker expression was a good prognostic indicator of patients' disease-free (p = 0.013) and overall survival (p = 0.043). Although we could not identify IDO1 as an independent prognostic factor, we found that high levels of IDO1 expression may further reduce survival outcomes in patients with low CCL19 expression. This could be vital for designing immuno therapeutic interventions targeting IDO1.

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.

Special Issue "HPV in the Head and Neck Region".

Previously, human papillomaviruses were best known for causing diseases in the genital tract, where high-risk types may cause, e.g., cancer of the cervix uteri, while low risk types could cause condylomas [...].

Investigation of the Epithelial to Mesenchymal Transition (EMT) Process in Equine Papillomavirus-2 (EcPV-2)-Positive Penile Squamous Cell Carcinomas.

Equine penile squamous cell carcinoma (epSCC) is the most frequent tumor of the external male genitalia, representing 67.5% of equine genital cancers. epSCC is associated with papilloma virus (PV) infection and has been recently proposed as a model for human PV-induced squamous cell carcinomas. It has already been suggested that epSCC might undergo epithelial-to-mesenchymal transition (EMT). This work aims to investigate in detail this process and the possible role of PV oncoproteins in epSCC. For this purpose, 18 penile SCCs were retrospectively selected and tested for both EcPV2 presence and oncoproteins (EcPV2 E6 and EcPV2 E7) expression. Moreover, immunohistochemical EMT characterization was carried out by analyzing the main epithelial markers (E-cadherin, ß-catenin, and pan-cytokeratin AE3/AE1), the main mesenchymal markers (N-cadherin and vimentin), and the main EMT-related transcription factors (TWIST-1, ZEB-1). PCR analysis was positive for EcPV2 in 16 out of 18 samples. EMT was investigated in epSCC positive for EcPV2. The immunohistochemistry results suggested the presence of EMT processes in the neoplastic cells at the tumor invasive front. Moreover, the significant upregulation of RANKL, together with BCATN1, LEF1, and FOSL1 genes, might suggest a canonical Wnt pathway activation, similarly to what is reported in human penile squamous cell carcinomas.

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.

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.

Human papillomavirus and ovarian cancer (review of literature and meta-analysis).

Many factors are involved in carcinogenesis of the ovary, such human genetic and physiological characteristics as lifestyle, existing diseases of the reproductive system, and, as suggested, the human papillomavirus (HPV). It is well known that the human papillomavirus virus of high carcinogenic risk (HCR) plays a crucial role in the onset and development of cervical cancer, as well as cases of HPV positive breast cancer and endometrial cancer. The data on the presence of HPV in ovarian cancer are ambiguous: the researchers claim that there is no complete effect of the virus on the development of this type of cancer, and the detection of HPV in 60-80% of tumors. In this regard, there is a need to systematize the currently available research results on this controversial issue and conduct a meta-analysis of the association of HPV infection with the risk of ovarian cancer.

Human Papillomavirus Types Associated with Cervical Dysplasia among HIV- and Non-HIV-Infected Women Attending Reproductive Health Clinics in Eastern Kenya.

BACKGROUND: Human papillomavirus (HPV) causes over 99% of all cervical cancer globally. In 2019, it was responsible for 3286 deaths in Kenya. Data on the epidemiological distribution of HPV genotypes by cervical dysplasia and HIV-infected women which is important in designing prevention strategy monitoring treatment and management of cervical cancer is lacking in Eastern Kenya. OBJECTIVE: To determine HPV genotype prevalence and their association with cervical dysplasia among HIV-infected (cases) and noninfected (control) women aged 18-48 years seeking reproductive healthcare. METHODS: A cervical broom was softly rotated 360 degrees five times to exfoliate cells from the region of the transformation zone, squamocolumnar junction, and endocervical canal for HPV genotyping. Social-demographic and risk factors responsible for HPV acquisition were collected using a questionnaire. Laboratory outcome and questionnaire data statistical relationships were computed using Pearson chi-square test. RESULTS: 317 women (cases: 161 (50.8%), control 156 (49.2%), mean age: 34.3,SD ± 10.4, range 18-46 years) were recruited from Embu (85/317 (26.8%)), Isiolo (64/317 (20.2%)), Kirinyaga (56/317 (17.7%)), Meru (81/317 (25.6%)), and Tharaka-Nithi (31/317 (9.8%)). The frequency HPV genotypes detected by cervical dysplasia were CIN1 (cases: HPV81 (12/317 (3.8%)), HPV11 (2/317 (0.6%)); control: HPV53 and 66 coinfection (1/317 (0.3%)), CIN2 (cases: HPV11, HPV16, HPV66 ((1/317 (0.3%) each), HPV81 (6/317 (1.9%)), and single case (1/317 (0.3%)) of HPV11 and 66, HPV81 and 44, HPV81 and 88, HPV9 and 53, and HPV16 and 58 coinfection; control: HPV81 (2/317 (0.6%)) and invasive cervical cancer (cases: HPV16 (1/317 (0.3%)) and HPV81 (3/317 (0.9%)); control: HPV16 and 66 (1/317 (0.3%))). CONCLUSIONS: There was a higher frequency of both high-risk and low-risk HPV genotypes associated with cervical dysplasia among HIV-infected than HIV-uninfected women seeking reproductive health care. This study provides epidemiological data on the existence of nonvaccine HPV types associated with cervical dysplasia in the region.

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.

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.

Papillomaviruses in Domestic Cats.

Papillomaviruses (PVs) are well established to cause hyperplastic papillomas (warts) in humans and animals. In addition, due to their ability to alter cell regulation, PVs are also recognized to cause approximately 5% of human cancers and these viruses have been associated with neoplasia in a number of animal species. In contrast to other domestic species, cats have traditionally been thought to less frequently develop disease due to PV infection. However, in the last 15 years, the number of viruses and the different lesions associated with PVs in cats have greatly expanded. In this review, the PV life cycle and the subsequent immune response is briefly discussed along with methods used to investigate a PV etiology of a lesion. The seven PV types that are currently known to infect cats are reviewed. The lesions that have been associated with PV infections in cats are then discussed and the review finishes with a brief discussion on the use of vaccines to prevent PV-induced disease in domestic cats.

Molecular Characterization of Human Papillomavirus Type 159 (HPV159).

Human papillomavirus type 159 (HPV159) was identified in an anal swab sample and preliminarily genetically characterized by our group in 2012. Here we present a detailed molecular in silico analysis that showed that the HPV159 viral genome is 7443 bp in length and divided into five early and two late genes, with conserved functional domains and motifs, and a non-coding long control region (LCR) with significant regulatory sequences that allow the virus to complete its life cycle and infect novel host cells. HPV159, clustering into the cutaneotropic Betapapillomavirus (Beta-PV) genus, is phylogenetically most similar to HPV9, forming an individual phylogenetic group in the viral species Beta-2. After testing a large representative collection of clinical samples with HPV159 type-specific RT-PCR, in addition to the anal canal from which the first HPV159 isolate was obtained, HPV159 was further detected in other muco-cutaneous (4/181, 2.2%), mucosal (22/764, 2.9%), and cutaneous (14/554, 2.5%) clinical samples, suggesting its extensive tissue tropism. However, because very low HPV159 viral loads were estimated in the majority of positive samples, it seemed that HPV159 mainly caused clinically insignificant infections of the skin and mucosa. Using newly developed, highly sensitive HPV159-specific nested PCRs, two additional HPV159 LCR viral variants were identified. Nevertheless, all HPV159 mutations were demonstrated outside important functional domains of the LCR, suggesting that the HPV159 viral variants were most probably not pathogenically different. This complete molecular characterization of HPV159 enhances our knowledge of the genome characteristics, tissue tropism, and phylogenetic diversity of Beta-PVs that infect humans.

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.

The Influence of Psychological Stress on HPV Infection Manifestations and Carcinogenesis.

Psychological stress is an important factor involved in disease manifestations of human papillomavirus (HPV) infection, and it can participate in HPV-associated carcinogenesis. The impact or effect which stress can have (exert) depends on a person's genetic pool, experiences and behaviors. Due to inconsistencies in some study results, this issue remains a subject of research. Concerning the course of HPV manifestations, it has been observed that a higher number of life stressors in at least the previous 6 months, the absence of social support and the types of personal coping mechanisms employed, all influence HPV progression. In women with cervical dysplasia, a connection between greater stress experiences and dysregulation of specific immune responses has been observed. Once HPV enters a cell via the α6 integrin there are three possible sequences: latent infection, subclinical infection, and clinically manifest disease. HPV proliferation in differentiated epithelial cells induces morphologically cytopathic changes (koilocytosis, epidermal thickening, hyperplasia, hyperkeratosis). Oncogenic transformation requires the integration of the virus genome into the host genome. In doing so, DNA in the E1 region of E2 breaks down, leading to transcription disorders of E6 and E7. For the formation of irreversible malignancy, the following sequence is necessary: initial expression of E6 and E7 genes followed by suppression of apoptosis and the stabile expression of E6 and E7 proteins that protect transformed cells from apoptosis. A successful immune response is characterized by a strong, local cell-mediated immune response. Several factors are important for the regression of HPV manifestation/infection, among which is psychological stress which can prolong the duration and severity of HPV disease. Stress hormones may reactivate latent tumor viruses, stimulate viral oncogene expression, and inhibit antiviral host responses. In the regression of HPV infection, increased activity of Th1 cells was observed. However, during psychosocial stress, a decrease in the Th1 type of immune response is seen, and there is a shift towards a Th2 response. Understanding perceived stress and biological changes in stress, as well as the evaluation of immune parameters, gives researchers a better picture of how stress influences HPV infections and how to improve disease management and outcomes.