Human papillomavirus molecular biology and disease association

Structural basis for recognition of the tumor suppressor protein PTPN14 by the oncoprotein E7 of human papillomavirus

Human papillomaviruses (HPVs) are causative agents of various diseases associated with cellular hyperproliferation, including cervical cancer, one of the most prevalent tumors in women. E7 is one of the two HPV-encoded oncoproteins and directs recruitment and subsequent degradation of tumor-suppressive proteins such as retinoblastoma protein (pRb) via its LxCxE motif. E7 also triggers tumorigenesis in a pRb-independent pathway through its C-terminal domain, which has yet been largely undetermined, with a lack of structural information in a complex form with a host protein. Herein, we present the crystal structure of the E7 C-terminal domain of HPV18 belonging to the high-risk HPV genotypes bound to the catalytic domain of human nonreceptor-type protein tyrosine phosphatase 14 (PTPN14). They interact directly and potently with each other, with a dissociation constant of 18.2 nM. Ensuing structural analysis revealed the molecular basis of the PTPN14-binding specificity of E7 over other protein tyrosine phosphatases and also led to the identification of PTPN21 as a direct interacting partner of E7. Disruption of HPV18 E7 binding to PTPN14 by structure-based mutagenesis impaired E7’s ability to promote keratinocyte proliferation and migration. Likewise, E7 binding-defective PTPN14 was resistant for degradation via proteasome, and it was much more effective than wild-type PTPN14 in attenuating the activity of downstream effectors of Hippo signaling and negatively regulating cell proliferation, migration, and invasion when examined in HPV18-positive HeLa cells. These results therefore demonstrated the significance and therapeutic potential of the intermolecular interaction between HPV E7 and host PTPN14 in HPV-mediated cell transformation and tumorigenesis.

Human papillomaviruses cause various diseases associated with cellular hyperproliferation, including cervical cancer. Structural, biochemical, and cellular analyses reveal the molecular basis and significance of the intermolecular interaction between the E7 protein of human papillomavirus 18 and the human tumor suppressor protein PTPN14.

The Humoral Immune Response Against the gB Vaccine: Lessons Learnt from Protection in Solid Organ Transplantation

Human cytomegalovirus (hCMV) is considered to be the highest priority for vaccine development. This view is underscored by the significant morbidity associated with congenital hCMV infection and viraemia in transplant patients. Although a number of vaccines have been trialed, none have been licensed. The hCMV vaccine candidate that has performed best in clinical trials to date is the recombinant glycoprotein B (gB) vaccine that has demonstrated protection, ranging from a 43% to 50% efficacy in three independent phase II trials. In this review, we focus on data from the phase II trial performed in solid organ transplant patients and the outcomes of follow-up studies attempting to identify immunological and mechanistic correlates of protection associated with this vaccine strategy. We relate this to other vaccine studies of gB as well as other vaccine strategies to determine areas of commonality and divergence. Finally, through the review, we discuss the unique challenges and opportunities presented with vaccine studies in transplant populations with recommendations that could empower subsequent trials.

Human DNA Virus Exploitation of the MAPK-ERK Cascade

The extracellular signal-regulated kinases (ERKs) comprise a particular branch of the mitogen-activated protein kinase cascades (MAPK) that transmits extracellular signals into the intracellular environment to trigger cellular growth responses. Similar to other MAPK cascades, the MAPK-ERK pathway signals through three core kinases—Raf, MAPK/ERK kinase (MEK), and ERK—which drive the signaling mechanisms responsible for the induction of cellular responses from extracellular stimuli including differentiation, proliferation, and cellular survival. However, pathogens like DNA viruses alter MAPK-ERK signaling in order to access DNA replication machineries, induce a proliferative state in the cell, or even prevent cell death mechanisms in response to pathogen recognition. Differential utilization of this pathway by multiple DNA viruses highlights the dynamic nature of the MAPK-ERK pathway within the cell and the importance of its function in regulating a wide variety of cellular fates that ultimately influence viral infection and, in some cases, result in tumorigenesis.

The Formation and Therapeutic Update of Tumor-Associated Macrophages in Cervical Cancer

Both clinicopathological and experimental studies have suggested that tumor-associated macrophages (TAMs) play a key role in cervical cancer progression and are associated with poor prognosis in the respects of tumor cell proliferation, invasion, angiogenesis, and immunosuppression. Therefore, having a clear understanding of TAMs is essential in treating this disease. In this review, we will discuss the origins and categories of macrophages, the molecules responsible for forming and reeducating TAMs in cervical cancer (CC), the biomarkers of macrophages and the therapy development targeting TAMs in CC research.

On-chip immunofluorescence analysis of single cervical cells using an electroactive microwell array with barrier for cervical screening

Several specific tests for cervical screening have been developed recently, including p16/Ki67 dual immunostaining for diagnosing high-risk human papillomavirus positive squamous intraepithelial lesion in the cervix. However, manual screening of cells in an entire glass slide is currently a standard clinical procedure for quantification and interpretation of immunocytochemical features of the cells. Here, we developed a microfluidic device containing an electroactive microwell array with barriers (EMAB) for highly efficient single-cell trapping followed by on-chip immunofluorescence analysis with minimum loss of the sample. EMAB utilizes patterned electrodes at the bottom of cell-sized microwells to trap single cells using dielectrophoresis (DEP) and cell-holding structures behind the microwells to stabilize the position of trapped cells even without DEP. Using the device, we evaluated the performance of p16/Ki67 dual immunostaining of HeLa cells on the chip. The device shows 98% cell-trapping efficiency as well as 92% cell-holding efficiency against the fixed HeLa cells, and we successfully demonstrated high-efficiency on-chip immunofluorescence analysis with minimal loss of sample. p16/Ki67 dual immunostaining using EMAB may be useful for complementary tests for cervical screening in confirming the histopathological diagnosis.

Ocular Human Papillomavirus Infections

CONTEXT

- Human papillomavirus (HPV) has a well-known role in the pathogenesis of squamous cell carcinoma and precursor lesions of the cervix, anogenital region, and head and neck, but its role in the development of squamous neoplasms of the eye, particularly the conjunctiva, remains unclear.

OBJECTIVE

- To review recent evidence implicating HPV in the pathophysiology of ocular lesions.

DATA SOURCES

- Published articles obtained from a PubMed search of the English literature were the primary sources for this review.

CONCLUSIONS

- The low-risk HPV types 6 and 11 appear to play a role in the development of at least a subset of conjunctival squamous papillomas. The role of HPV in the pathogenesis of pterygium and ocular surface squamous neoplasia is less well defined. There is evidence to suggest that HPV may be a cofactor in the development of these lesions, acting in concert with ultraviolet radiation and/or human immunodeficiency virus infection in a subgroup of cases.

Human Papillomavirus 11 Early Protein E6 Activates Autophagy by Repressing AKT/mTOR and Erk/mTOR

Low-risk human papillomaviruses (LR-HPVs) are the causative agents of genital warts, which are a widespread sexually transmitted disease. How LR-HPVs affect autophagy and the specific proteins involved are unknown. In the current study, we investigated the impact of LR-HPV11 early protein 6 (E6) on the activity of the autophagy pathway. We transfected an HPV11 E6 (11E6) plasmid into HaCaT cells, H8 cells, and NHEK cells and established a stable cell line expressing the HPV11 E6 protein. The differences in autophagy activity and upstream regulatory pathways compared with those in the parent cell lines were investigated using a Western blot analysis of the total and phosphorylated protein levels and confocal microscopy of immunostained cells and cells transfected with an mCherry-green fluorescent protein-LC3 expression plasmid. We used short hairpin RNA (shRNA) to knock down 11E6 and showed that these effects require continued 11E6 expression. Compared with its expression in the control cells, the expression of HPV11 E6 in the cells activated the autophagy pathway. The increased autophagy activity was the result of the decreased phosphorylation levels of the canonical autophagy repressor mammalian target of rapamycin (mTOR) at its Ser2448 position (the mTOR complex 1 [mTORC1] phosphorylation site) and decreased AKT and Erk phosphorylation. Therefore, these results indicate that HPV11 E6 activates autophagy through the AKT/mTOR and Erk/mTOR pathways. Our findings provide novel insight into the relationship between LR-HPV infections and autophagy and could help elucidate the pathogenic mechanisms of LR-HPV.IMPORTANCE We transfected an HPV11 E6 plasmid into HaCaT cells, H8 cells, and NHEK cells and established a stable cell line expressing the HPV11 E6 protein. Then, we confirmed that HPV11 E6 induces autophagy by suppressing the AKT/mTOR and Erk/mTOR pathways. In contrast to the high-risk HPV E6 genes, HPV11 E6 did not affect the expression of p53. To the best of our knowledge, this study represents the first direct in-depth investigation of the relationship between the LR-HPV E6 gene and autophagy, which may help to reveal the pathogenesis of LR-HPV infection.

Abundance of HPV L1 Intra-Genotype Variants With Capsid Epitopic Modifications Found Within Low- and High-Grade Pap Smears With Potential Implications for Vaccinology

Background: The aim of this study was to explore the Human Papillomavirus (HPV) genotype composition and intra-genotype variants within individual samples of low- and high-grade cervical cytology by deep sequencing. Clinical, cytological, sequencing, and functional/structural data were forged into an integrated variant profiling pipeline for the detection of potentially vaccine-resistant genotypes or variants.

Methods: Low- and high-grade intraepithelial lesion (LSIL and HSIL) cytology samples with +HPV were subjected to amplicon (L1 gene fragment) sequencing by dideoxy (Sanger) and deep methods. Taxonomic, abundance, diversity, and phylogenetic analyses were conducted to determine HPV genotypes/sub-lineages, relative abundance, species diversity and phylogenetic distances within and between samples. Variant detection and functional analysis of translated L1 amino acid sequences determined structural variations of interest.

Results: Pure and mixed HPV infections were common among LSIL (n = 6) and HSIL (n = 6) samples. Taxonomic profiling revealed loss of species richness and gain of dominance by carcinogenic genotypes in HSIL samples. Phylogenetic analysis showed excellent correlation between HPV-type specific genetic distances and carcinogenic potential. For combined LSIL/HSIL samples (n = 12), 11 HPV genotypes and 417 mutations were detected: 375 single-nucleotide variants (SNV), 29 insertion/deletion (indel), 12 multi-nucleotide variants (MNV), and 1 replacement variant. The proportion of nonsynonymous mutations was lower for HSIL (0.38) than for LSIL samples (0.51) (p < 0.05). HPV variant analysis pinpointed nucleotide-level mutations and amino acid-level structural modifications.

Conclusion: HPV L1 intra-host and intra-genotype variants are abundant in LSIL and HSIL samples with potential functional/structural consequences. An integrated multi-omics approach to variant analysis may provide a sensitive and practical means of detecting changes in HPV evolution and dynamics within individuals or populations.

Phosphorylation of a Conserved Tyrosine in the Papillomavirus E2 Protein Regulates Brd4 Binding and Viral Replication

The papillomavirus (PV) E2 protein coordinates viral transcription and genome replication. Following a strategy to identify amino acids in E2 that are posttranslationally modified, we reported that tyrosine kinase fibroblast growth factor receptor 3 (FGFR3) complexes with and phosphorylates E2, which inhibits viral DNA replication. Here, we present several lines of evidence indicating that tyrosine (Y) 138 of HPV-31 E2 is a substrate of FGFR3. The active form of FGFR3 bound to and phosphorylated the region of amino acids (aa) 107 to 175 in HPV-31 E2. The E2 phenylalanine (F) mutant Y138F displayed reduced FGFR3-induced phosphotyrosine. A constitutive kinase-active FGFR3 inhibited wild-type (WT) E2-induced E1-dependent DNA replication, while the 138F mutant retained activity. The tyrosine to glutamic acid (E) mutant Y138E, which can mimic phosphotyrosine, failed to induce transient DNA replication, although it maintained the ability to bind and localize the viral DNA helicase E1 to the viral origin. The bromodomain-containing protein 4 (Brd4) binds to E2 and is necessary for initiation of viral DNA synthesis. Interestingly, the Y138E protein coimmunoprecipitated with full-length Brd4 but was defective for association with its C-terminal domain (CTD). These results imply that the activity of the FGFR3 kinase in the infected epithelial cell restricts the HPV replication program through phosphorylation of E2 at Y138, which interferes with E2 binding to the Brd4 CTD, and that this interaction is required for initiation of viral DNA synthesis.IMPORTANCE Human papillomaviruses (HPVs) are highly infectious pathogens that commonly infect the oropharynx and uterine cervix. The idea that posttranslational modifications of viral proteins coordinates viral genome replication is less explored. We recently discovered that fibroblast growth factor receptor 3 (FGFR3) phosphorylates the viral E2 protein. The current study demonstrates that FGFR3 phosphorylates E2 at tyrosine 138, which inhibits association with the C-terminal peptide of Brd4. This study illustrates a novel regulatory mechanism of virus-host interaction and provides insight into the role of Brd4 in viral replication.

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.

Roles for E1-independent replication and E6-mediated p53 degradation during low-risk and high-risk human papillomavirus genome maintenance

Human papillomaviruses (HPV) have genotype-specific disease associations, with high-risk alpha types causing at least 5% of all human cancers. Despite these conspicuous differences, our data show that high- and low- risk HPV types use similar approaches for genome maintenance and persistence. During the maintenance phase, viral episomes and the host cell genome are replicated synchronously, and for both the high- and low-risk HPV types, the E1 viral helicase is non-essential. During virus genome amplification, replication switches from an E1-independent to an E1-dependent mode, which can uncouple viral DNA replication from that of the host cell. It appears that the viral E2 protein, but not E6 and E7, is required for the synchronous maintenance-replication of both the high and the low-risk HPV types. Interestingly, the ability of the high-risk E6 protein to mediate the proteosomal degradation of p53 and to inhibit keratinocyte differentiation, was also seen with low-risk HPV E6, but in this case was regulated by cell density and the level of viral gene expression. This allows low-risk E6 to support genome amplification, while limiting the extent of E6-mediated cell proliferation during synchronous genome maintenance. Both high and low-risk E7s could facilitate cell cycle re-entry in differentiating cells and support E1-dependent replication. Despite the well-established differences in the viral pathogenesis and cancer risk, it appears that low- and high-risk HPV types use fundamentally similar molecular strategies to maintain their genomes, albeit with important differences in their regulatory control. Our results provide new insights into the regulation of high and low-risk HPV genome replication and persistence in the epithelial basal and parabasal cells layers. Understanding the minimum requirement for viral genome persistence will facilitate the development of therapeutic strategies for clearance.

Single-Domain Antibodies Represent Novel Alternatives to Monoclonal Antibodies as Targeting Agents against the Human Papillomavirus 16 E6 Protein

Approximately one fifth of all malignancies worldwide are etiologically associated with a persistent viral or bacterial infection. Thus, there is a particular interest in therapeutic molecules which use components of a natural immune response to specifically inhibit oncogenic microbial proteins, as it is anticipated they will elicit fewer off-target effects than conventional treatments. This concept has been explored in the context of human papillomavirus 16 (HPV16)-related cancers, through the development of monoclonal antibodies and fragments thereof against the viral E6 oncoprotein. Challenges related to the biology of E6 as well as the functional properties of the antibodies themselves appear to have precluded their clinical translation. Here, we addressed these issues by exploring the utility of the variable domains of camelid heavy-chain-only antibodies (denoted as VHHs). Through construction and panning of two llama, immune VHH phage display libraries, a pool of potential VHHs was isolated. The interactions of these with recombinant E6 were further characterized using an enzyme-linked immunosorbent assay (ELISA), Western blotting under denaturing and native conditions, and surface plasmon resonance. Three VHHs were identified that bound recombinant E6 with nanomolar affinities. Our results lead the way for subsequent studies into the ability of these novel molecules to inhibit HPV16-infected cells in vitro and in vivo.

Differential Activation of ERK Signaling in HPV-Related Oropharyngeal Squamous Cell Carcinoma

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) forms a distinct tumor entity with better survival clinical outcome. Numerous underlying molecular mechanisms have been postulated for differences in treatment response, but the impact of MEK/ERK signaling, a main driver of carcinogenesis in various cancers including OPSCC and key player mediating therapy resistance remains elusive. In a retrospective experimental cohort study, primary tumor samples from OPSCC patients (n = 124) were available on tissue microarrays (TMAs) and expression levels of phosphorylated ERK1/2 (pERK1/2) were detected by immunohistochemical staining. Correlations of pERK1/2 expression patterns with clinicopathological features and clinical outcome were evaluated by statistical analysis. A low pERK1/2 expression was strongly associated with HPV-related OPSCC, while primary tumors with high pERK1/2 staining showed a distinctly worse survival outcome and were associated with higher cellular differentiation. Co-activation of both ERK1/2 and AKT was a common event and was associated with unfavorable prognosis in our cohort. However, the combinatorial analysis of pAKT (Ser473) and pERK1/2 did not strengthen the predictive power of pERK1/2, suggesting that pERK1/2 plays a more significant function in OPSCC. In summary, our data provide a compelling experimental and statistical evidence that low levels of tumor cell intrinsic ERK1/2 activation contribute at least in part to the favorable outcome of HPV-related OPSCC. On the other hand, presented findings indicate that non-HPV-related OPSCC with elevated ERK phosphorylation are at high risk for treatment failure and might benefit from targeted therapy of MEK/ERK signaling.

Cross-hybridization between HPV genotypes in the Linear Array Genotyping Test confirmed by Next-Generation Sequencing

Background

Linear Array Genotyping Test (LA) is one of the gold standards used for Human Papillomavirus (HPV) genotyping, however, since its launching in 2006, new HPV genotypes are still being characterized with the use of high specificity techniques such as Next-Generation Sequencing (NGS). Derived from a previous study of the IMSS Research Network on HPV, which suggested that there might be cross-reaction of some HPV genotypes in the LA test, the aim of this study was to elucidate this point.

Methods

Double stranded L1 fragments (gBlocks) from different HPVs were used to perform LA test, additionally, 14 HPV83+ and 26 HPV84+ cervical samples determined with LA, were individually genotyped by NGS.

Results

From the LA HPV83+ samples, 64.3% were truly HPV83+, while 42.9% were found to be HPV102+. On the other hand, 69.2% of the LA HPV84+ samples were HPV84+, while 3.8, 11.5 and 30.8% of the samples were indeed HPV 86, 87 and 114 positive, respectively. Additionally, novel nucleotide changes in L1 gene from HPV genotypes 83, 84, 87, 102 and 114 were determined in Mexican cervical samples, some of them lead to changes in the protein sequence.

Conclusions

We demonstrated that there is cross-hybridization between alpha3-HPV genotypes 86, 87 and 114 with HPV84 probe in LA strips and between HPV102 with HPV83 probe; this may be causing over or under estimation in the prevalence of these genotypes. In the upcoming years, a switch to more specific and sensitive genotyping methods that detect a broader spectrum of HPV genotypes needs to be implemented.

Role of DNA methylation in HPV associated lesions

Papillomavirus replication is tightly linked to squamous epithelial differentiation which in turn is governed to a large extent by epigenetic remodeling of genomes within the differentiating squamous epithelial cells. Over the past years it became evident that epigenetic and in particular differential methylation events substantially contribute to the regulation of the papillomavirus life cycle. Moreover, there is now good evidence that the initial trigger for HPV-mediated transformation of squamous epithelial cells is mediated by methylation of distinct CpG dinucleotides within E2-binding sites of the papillomavirus upstream regulatory region (URR). These findings have important implications for novel diagnostic markers but also for novel and indeed targeted therapy strategies for HPV linked neoplastic lesions.

Refining our understanding of cervical neoplasia and its cellular origins

Human papillomaviruses (HPV) cause cancer at a number of vulnerable epithelial sites, including the cervix, the anus and the oropharynx, with cervical cancer being the most significant in terms of numbers. The cervix has a complex epithelial organisation, and comprises the stratified epithelium of the ectocervix, the columnar epithelium of the endocervix, and the cervical transformation zone (TZ). Most cervical cancers arise at the TZ, which is a site where a stratified squamous epithelium can develop via metaplasia from a simple columnar epithelium. It is thought that this process is mediated by the cervical reserve cell, a specialised type of stem cell that is located at the TZ, which has been proposed as the target cell for HPV infection. Reserve cells may be derived from the basal cells of the ectocervix, or may originate from the cuboidal cells found at the squamo columnar junction. It appears that HPV infection of these diverse cell types, including the columnar cells of the endocervix, facilitates deregulated viral gene expression and the development of neoplasia, with different epithelial sites having different cancer risk. It is envisaged that these concepts may explain the vulnerability of the oropharynx, and other TZ regions where HPV-associated cancers arise.

Towards Understanding of Polymorphism of the G-rich Region of Human Papillomavirus Type 52

The potential to affect gene expression via G-quadruplex stabilization has been extended to all domains of life, including viruses. Here, we investigate the polymorphism and structures of G-quadruplexes of the human papillomavirus type 52 with UV, CD and NMR spectroscopy and gel electrophoresis. We show that oligonucleotide with five G-tracts folds into several structures and that naturally occurring single nucleotide polymorphisms (SNPs) have profound effects on the structural polymorphism in the context of G-quadruplex forming propensity, conformational heterogeneity and folding stability. With help of SNP analysis, we were able to select one of the predominant forms, formed by G-rich sequence d(G₃TAG₃CAG₄ACACAG₃T). This oligonucleotide termed HPV52_(1-4) adopts a three G-quartet snap back (3 + 1) type scaffold with four syn guanine residues, two edgewise loops spanning the same groove, a no-residue V loop and a propeller type loop. The first guanine residue is incorporated in the central G-quartet and all four-guanine residues from G4 stretch are included in the three quartet G-quadruplex core. Modification studies identified several structural elements that are important for stabilization of the described G-quadruplex fold. Our results expand set of G-rich targets in viral genomes and address the fundamental questions regarding folding of G-rich sequences.

Human papillomavirus (HPV) and somatic EGFR mutations are essential, mutually exclusive oncogenic mechanisms for inverted sinonasal papillomas and associated sinonasal squamous cell carcinomas

Background

Inverted sinonasal (Schneiderian) papilloma (ISP) is a locally aggressive neoplasm often associated with sinonasal squamous cell carcinoma (SNSCC). While the etiology of ISP is not well understood, human papillomavirus (HPV) has been detected in a subset of cases. Our group recently identified activating somatic EGFR mutations in the majority of ISP and ISP-associated SNSCC. However, the relationship between EGFR mutations and HPV infection has not been explored.

Patients and methods

We evaluated 58 ISP and 22 ISP-associated SNSCC (including 13 patients with matched ISP/SNSCC samples), as well as 14 SNSCC without clinical or pathologic evidence of an associated ISP. Formalin-fixed, paraffin-embedded samples were evaluated for EGFR mutations using Sanger sequencing and for HPV infection using GP5+/GP6+ PCR. HPV subtyping based on the L1 sequence was done for HPV positive cases including temporally distinct tumors for four patients. Clinicopathologic data including progression free survival was also analyzed.

Results

All ISP and ISP-associated SNSCC demonstrated either an EGFR mutation or HPV infection. HPV and EGFR mutation were mutually exclusive in all cases of ISP-associated SNSCC and all but one ISP; this case was only weakly HPV positive, and analysis of a prior temporally distinct ISP specimen from this patient failed to show HPV infection, suggesting transient infection/incidental colonization. HPV subtypes in ISP and ISP-associated SNSCC were predominantly low-risk, in contrast with SNSCC without ISP association, which showed frequent high-risk HPV. All paired ISP and associated SNSCC samples demonstrated concordant HPV status and EGFR genotypes. ISP progression to SNSCC was significantly associated with the presence of HPV infection and the absence of an EGFR mutation (log-rank = 9.620, P = 0.002).

Conclusions

Collectively our data show that EGFR mutations and HPV infection represent essential, alternative oncogenic mechanisms in ISP and ISP-associated SNSCC.

Condyloma acuminata on the nipple and coronary sulcus of the penis: A case report

RATIONALE

Condyloma acuminatum (CA) is a benign tumor primarily caused by infection with human papillomavirus (HPV) type-6 or type-11, lesions of which are most frequently found on the genital and perianal squamous mucosa and skin. CA outside the genitals is not common.

PATIENT CONCERNS

A 29-year-old male presented with lesions on the left nipple and coronary sulcus after heterosexual contact.

DIAGNOSES

Histopathological examination and HPV detection made a definite diagnosis of CA.

INTERVENTION

The patient was treated with microwave and topical imiquimod cream.

OUTCOMES

After 6 months follow-up, there was no sign of recurrence.

LESSONS

This case shows that we should pay more attention to CA outside the genitals in the process of diagnosis and treatment.

Human Papillomavirus (HPV) Infection in Early Pregnancy: Prevalence and Implications

Introduction

Young women (20-35 years) are at high risk of HPV infection, although the majority of the infections are asymptomatic and are cleared spontaneously by the host immune system. These are also the group of women who are sexually active and are in the population of pregnant women. During pregnancy, the changes in the hormonal milieu and immune response may favor persistence of HPV infection and may aid in transgenerational transmission thereby furthering the cancer risk. In the present study, we determined the prevalence of vaginal HPV infection in early pregnancy and attempted to relate with pregnancy outcome.

Material and Methods

Vaginal cytology samples were collected from the condoms used to cover the vaginal sonography probe during a routine first trimester visit to the hospital. All women were followed up throughout pregnancy and childbirth. Maternal and neonatal outcomes were recorded.

Results

We found a prevalence of HPV infection around 39.4% in our population. Interestingly all HPV positive women were infected with one or more high risk HPV viruses with an overlap of intermediate and low risk in 43% and 7.3%, respectively. Women with preterm prelabor rupture of membranes (PPROM) showed a statistically higher incidence in HPV positive (7.3%) group as compared to the HPV negative (3.2%) group.

Conclusion

The prevalence of genital HPV infection is high during pregnancy (around 40%) and was associated with higher incidence of PPROM.

PTPN14 degradation by high-risk human papillomavirus E7 limits keratinocyte differentiation and contributes to HPV-mediated oncogenesis

High-risk human papillomavirus (HPV) E7 proteins enable oncogenic transformation of HPV-infected cells by inactivating host cellular proteins. High-risk but not low-risk HPV E7 target PTPN14 for proteolytic degradation, suggesting that PTPN14 degradation may be related to their oncogenic activity. HPV infects human keratinocytes but the role of PTPN14 in keratinocytes and the consequences of PTPN14 degradation are unknown. Using an HPV16 E7 variant that can inactivate retinoblastoma tumor suppressor (RB1) but cannot degrade PTPN14, we found that high-risk HPV E7-mediated PTPN14 degradation impairs keratinocyte differentiation. Deletion of PTPN14 from primary human keratinocytes decreased keratinocyte differentiation gene expression. Related to oncogenic transformation, both HPV16 E7-mediated PTPN14 degradation and PTPN14 deletion promoted keratinocyte survival following detachment from a substrate. PTPN14 degradation contributed to high-risk HPV E6/E7-mediated immortalization of primary keratinocytes and HPV⁺ but not HPV^- cancers exhibit a gene-expression signature consistent with PTPN14 inactivation. We find that PTPN14 degradation impairs keratinocyte differentiation and propose that this contributes to high-risk HPV E7-mediated oncogenic activity independent of RB1 inactivation.

HPV type 16 E6 and NFX1-123 augment JNK signaling to mediate keratinocyte differentiation and L1 expression

The HPV life cycle is differentiation-dependent, with cellular differentiation driving initiation of the late, productive stage of the viral life cycle. Here, we identify a role for the protein NFX1-123 in regulating keratinocyte differentiation and events of the late HPV life cycle. NFX1-123 itself increased with differentiation of epithelial cells. Greater NFX1-123 augmented differentiation marker expression and JNK phosphorylation in differentiating 16E6-expressing human foreskin keratinocytes (16E6 HFKs). This was associated with altered expression of MKK4 and MKK7, upstream kinase regulators of JNK phosphorylation. Modulating levels of NFX1-123 in HPV16-positive W12E cells recapitulated the effects on differentiation markers, JNK phosphorylation, and MKK4/7 seen in 16E6 HFKs. Crucially, levels of NFX1-123 also correlated with expression of L1, the capsid protein of HPV. Altogether, these studies define a role for NFX1-123 in mediating epithelial differentiation through the JNK signaling pathway, potentially linking expression of cellular genes and HPV genes during differentiation.

Effect of Multiple Vaccinations with Tumor Cell-Based Vaccine with Codon-Modified GM-CSF on Tumor Growth in a Mouse Model

Ectopic expression of codon-modified granulocyte-macrophage colony-stimulating factor (cGM-CSF) in TC-1 cells (TC-1/cGM-CSF), a model cell line for human papillomavirus (HPV)-infected cervical cancer cells, increased the expression level of GM-CSF and improved the efficacy of tumor cell-based vaccines in a cervical cancer mouse model. The number of vaccine doses required to induce a long-term immune response in a cervical cancer mouse model is poorly understood. Here, we investigated one, three, and five doses of the irradiated TC-1/cGM-CSF vaccine to determine which dose was effective in inducing a greater immune response and the suppression of tumors. Our findings showed that three doses of irradiated TC-1/cGM-CSF vaccine elicited slower tumor growth rates and enhanced survival rates compared with one dose or five doses of irradiated TC-1/cGM-CSF vaccine. Consistently, mice vaccinated with three doses of irradiated TC-1/cGM-CSF vaccine exhibited stronger interferon gamma (IFN-γ) production in HPV E7-specific CD8⁺ T cells and CD4⁺ T cells. A higher percentage of natural killer cells and interferon-producing killer dendritic cells (IKDCs) appeared in the splenocytes of the mice vaccinated with three doses of irradiated TC-1/cGM-CSF vaccine compared with those of the mice vaccinated with one dose or five doses of irradiated TC-1/cGM-CSF vaccine. Our findings demonstrate that single or multiple vaccinations, such as five doses, with irradiated TC-1/cGM-CSF vaccine suppressed the immune response, whereas three doses of irradiated TC-1/cGM-CSF vaccine elicited a greater immune response and subsequent tumor suppression.

HPV infection and pre-term birth: a data-linkage study using Scottish Health Data

Background: We aimed to investigate whether infection with high-risk (HR) types of human papilloma virus (HPV) or HPV-associated cervical disease were associated with preterm birth (<37 weeks gestation). In a sub-group of younger women who were eligible for the HPV vaccine, we aimed to determine whether prior vaccination against the specific HPV-types, HPV-16 and -18 modified preterm birth risk. Methods: This was a data-linkage study, which linked HPV-associated viral and pathological information (from the Scottish HPV Archive) from women aged 16-45 years to routinely collected NHS maternity- and hospital-admission records from 1999-2015. Pregnancy outcomes from 5,598 women with term live birth (≥37 weeks gestation, n=4,942), preterm birth (<37 weeks gestation, n=386) or early miscarriage (<13 weeks gestation, n=270). Of these, data from HPV vaccine-eligible women (n=3,611, aged 16-25 years) were available, of whom 588 had been vaccinated. HPV-associated disease status was defined as: HR HPV-positive no disease, low-grade abnormalities or high-grade disease. Results: High-grade HPV-associated cervical disease was associated with preterm birth (odds ratio=1.843 [95% confidence interval 1.101-3.083], p=0.020) in adjusted binary logistic regression analysis, in all women, but there were no associations with HR HPV-infection alone or with low-grade abnormalities. No associations between any HPV parameter and preterm birth were seen in vaccine-eligible women, nor was there any effect of prior vaccination. Conclusions: HPV-associated high-grade cervical disease was associated with preterm birth, but there were no associations with HR HPV-infection or low-grade cervical disease. Thus HPV-infection alone (in the absence of cervical disease) does not appear to be an independent risk factor for preterm birth. For women who have undergone treatment for CIN and become pregnant, these results demonstrate the need to monitor for signs of preterm birth.

Induction of neutralizing antibodies by human papillomavirus vaccine generated in mammalian cells

Background

Cervical cancer caused by human papillomavirus (HPV) infections is one of the most common cancers affecting women worldwide. Current preventative HPV vaccines on the market are composed of HPV L1 protein produced either in the yeast such as Gardasil or in the insect cells such as Cervarix. The duration of efficacy and cross-protection remain highly desirable for the improvement of current prophylactic HPV vaccine. Given that HPV carries out infection and replicates in mammalian cells, L2 protein, which is not included in the current licensed vaccines, is included in the third generation of HPV vaccine in pursuing of providing broader prevention. We hypothesize that a virus-like particle (VLP) consisting of HPV L1 plus L2 proteins generated in mammalian cells will present conformations more closely to native HPV, thus it will provide more durable and broader efficacy of prevention.

Methods

We took advantage of 293TT cells to produce VLP containing L1 and L2 proteins of HPV16 and HPV18, respectively.

Results

VLP particles of uniformed size and morphology were observed, and potent and broadly neutralizing antibodies were induced in mice and rabbits. In addition, compared to bivalent HPV vaccine of Cervarix, our HPV L1-L2 VLPs elicited higher titer of anti-sera, and the anti-sera also presented comparable neutralization potency against HPV16 and HPV18 infections even a much less potent adjuvant was used in our case.

Conclusion

Our VLPs were capable of eliciting stronger and more broadly neutralizing activities against various HPV subtypes and were potential candidate HPV vaccines.

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

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

PD-1/PD-L1 blockade in cervical cancer: current studies and perspectives

Cervical cancer (CC) is the fourth most commonly diagnosed female malignancy and a leading cause of cancer-related mortality worldwide, especially in developing countries. Despite the use of advanced screening and preventive vaccines, more than half of all CC cases are diagnosed at advanced stages, when therapeutic options are extremely limited and side effects are severe. Given these circumstances, new and effective treatments are needed. In recent years, exciting progress has been made in immunotherapies, including the rapid development of immune checkpoint inhibitors. Checkpoint blockades targeting the PD-1/PD-L1 axis have achieved effective clinical responses with acceptable toxicity by suppressing tumor progression and improving survival in several tumor types. In this review, we summarize recent advances in our understanding of the PD-1/PD-L1 signaling pathway, including the expression patterns of PD-1/PD-L1 and potential PD-1/PD-L1-related therapeutic strategies for CC.

Prevalence of human papillomavirus and subtype distribution in male partners of women with cervical intraepithelial neoplasia (CIN): a systematic review

BACKGROUND

Human Papillomavirus (HPV) infection is estimated to be the most common sexually transmitted infection. The present systematic review summarizes data regarding the prevalence of HPV and the distribution of subtypes in heterosexual male partners of women, who were diagnosed with any grade of cervical intraepithelial neoplasia (CIN).

METHODS

We conducted a systematic review of the literature by Medline and Google Scholar databases using the terms "Human Papillomavirus" or "HPV" plus "men" or "male partners" or "women with CIN". We included original published English-language articles published from 1/1/2000 until 1/1/2018 that had screened male partners of women with CIN using HPV DNA testing. We excluded studies that they overlapped with other included studies or were unrelated to the study subject.

RESULTS

We included a total of 12 publications, which reported the prevalence of HPV in free-clinical signs male partners of women with CIN. The largest proportion of the studies were from South America (seven studies), and the rest from Europe. The mean age of participants was 35.18 + - 3.47 years. HPV prevalence ranged from 12.9 to 86%; the total HPV prevalence among the studies was 49.1%, while ten out twelve studies (83.3%) demonstrated prevalence > 20%. Between the studies, the distribution of HPV subtypes varied on the basis of the method used, on the population and on the geographic region. A great variety of subtypes were detected, including 6, 11, 16, 18, 31, 33, 40, 42, 45, 51, 52, 53, 54, 56, 57, 58, 59, 61, 62, 66, 68, 81 and 83. In six studies the HPV 16 was the most frequent, while in two others the HPV 6 and HPV 83.

CONCLUSIONS

Until now, there are not precise screening or surveillance guidelines for the management of partners of women with CIN. This population is frequently colonized by various HPV subtypes and therefore need to be screened in an effort to reduce the infection in both sexes. The screening test could include detection/identification of HPV subtypes by a molecular assay, followed by peniscopy only in the positive cases.

Anal carcinoma in giant anal condyloma, multidisciplinary approach necessary for optimal outcome: Two case reports and review of literature

BACKGROUND

Anal cancers are caused by human papilloma virus (HPV). Buschke-Lowenstein tumor also known as giant anal condyloma (GCA) is a variant of giant neglected anal tumors arising from warts caused by HPV infection. HPV are a family of double-stranded DNA viruses and primarily cause sexually transmitted disease of the genitalia and oropharyngeal mucosa. These tumors are slow growing; locally destructive large verrucous masses.

CASE SUMMARY

We present a series of two cases with large anal tumors harboring invasive cancers and highlight their presentation and management. Tumors with high risk HPV subtypes (HPV 16, 18, 31, 33) may progress into invasive squamous cell carcinoma (SCC). Untreated GCA can attain enormous size and extend into the pelvic organs and bony structures. Some tumors show malignant degeneration into SCC and are often difficult to diagnose given the large size of the tumors. Complete surgical excision with negative margins is the treatment of choice and necessary to prevent recurrence. This is often not feasible and leaves large surgical wounds with tissue defects with delay in healing and increases post-operative morbidity. Pelvic reconstructive techniques including muscle flaps and grafts are often necessary to close the defects. Human immunodeficiency virus and immunocompromised patients generally do poorly with standard treatments.

CONCLUSION

A multidisciplinary team of colorectal and plastic surgeons, medical and radiation oncologists along with combination treatment modalities are necessary when malignant transformation occurs in GCA, for optimal outcomes.

Persuasive messaging for human papillomavirus vaccination by adolescent providers in a five-country multi-site study

OBJECTIVE

Strong persuasive messaging by providers is a key predictor for patient acceptance of prophylactic human papillomavirus vaccination. We aimed to determine optimal messaging to promote human papillomavirus adolescent vaccination across different geographical sites.

METHODS

Adolescent providers (n = 151) from Argentina, Malaysia, South Africa, South Korea, and Spain were surveyed on messages, family decision makers, and sources of communication to best motivate parents to vaccinate their adolescent daughters overall, and against human papillomavirus. Multivariate logistic regression assessed the likelihood of recommending messages specifically targeted at cervical cancer with providers' characteristics: gender, medical specialization, and previous administration of human papillomavirus vaccination.

RESULTS

Mothers were considered the most important human papillomavirus vaccination decision makers for their daughters (range 93%-100%). Television was cited as the best source of information on human papillomavirus vaccination in surveyed countries (range 56.5%-87.1%), except Spain where one-on-one discussions were most common (73.3%). Prevention messages were considered the most likely to motivate parents to vaccinate their daughters overall, and against human papillomavirus, in all five countries (range 30.8%-55.9%). Optimal messages emphasized cervical cancer prevention, and included strong provider recommendation to vaccinate, vaccine safety and efficacy, timely vaccination, and national policy for human papillomavirus vaccination. Pediatricians and obstetricians/gynecologists were more likely to cite that the best prevention messages should focus on cervical cancer (OR: 4.2, 95% CI: 1.17 to 15.02 vs other medical specialists).

CONCLUSIONS

Provider communication messages that would motivate parents to vaccinate against human papillomavirus were based on strong recommendation emphasizing prevention of cervical cancer. To frame convincing messages to increase vaccination uptake, adolescent providers should receive updated training on human papillomavirus and associated cancers, while clearly addressing human papillomavirus vaccination safety and efficacy.

Association of estradiol and HPV/HPV16 infection with the occurrence of cervical squamous cell carcinoma

The associations between human papillomavirus (HPV) infection or hormonal exposure and cervical cancer risk are well established. However, to the best of our knowledge, the association between high endogenous estradiol levels in conjunction with HPV/HPV16 infection and the risk of cervical squamous cell carcinoma remains unknown. To investigate this, the current study conducted a matched case-control study in Shanxi Province, China, in which clinical samples were obtained from 74 females with newly diagnosed uterine cervix squamous cell carcinoma and 74 matched healthy females who were selected from 582 healthy females according to age, place of residence, marital status and menopausal status. From all participants, DNA was extracted from cells obtained from a cervical smear and serum was separated from venous blood withdrawn during days 5-8 of the menstrual cycle. HPV/HPV16 DNA and estradiol expression levels in the serum were measured by general polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Significant differences were identified in the positive HPV and HPV16 DNA expression rates between patients and controls, with odds ratios (95% confidence interval) of 3.74 (1.84-7.59) and 4.04 (1.97-8.28), respectively. Expression levels of estradiol in patients were significantly higher compared with the controls (P<0.001), however, this was only identified when the HPV16 E2 or E6 oncogene status was negative. Considering 40 ng/ml as the cut-off estradiol level, 78.38% of patients exhibited high estradiol levels, which was significantly higher than the percentage of controls (P<0.001). An additive interaction pattern was revealed between estradiol expression levels and HPV/HPV16 infection. The results suggest that among the various types of HPV, HPV16 may be most likely to cause uterine cervix squamous cell carcinoma and an abnormally high level of endogenous estradiol may further increase this risk. Therefore, estradiol therapy may represent a new treatment strategy for cases of cervical cancer associated with HPV infection.

Biological activities of Ficus carica latex for potential therapeutics in Human Papillomavirus (HPV) related cervical cancers

Infection caused by high-risk human papillomaviruses (HPVs) are implicated in the aetiology of cervical cancer. Although current methods of treatment for cervical cancer can ablate lesions, preventing metastatic disseminations and excessive tissue injuries still remains a major concern. Hence, development of a safer and more efficient treatment modality is of vital importance. Natural products from plants are one of the principal sources of precursors to lead compounds with direct pharmaceutical application across all disease classes. One of these plants is Ficus carica, whose fruit latex, when applied on HPV-induced skin warts, has shown potential as a possible cure for this virus related lesions. This study explores the in vitro biological activities of fig latex and elucidates its possible mechanisms of action on cervical cancer cell lines CaSki and HeLa positive for HPV type 16 and 18, respectively. Our data shows that fig latex inhibits properties that are associated with HPV-positive cervical cancer transformed cells such as rapid growth and invasion and substantially downregulated the expression of p16 and HPV onco-proteins E6, E7. These findings suggest Ficus carica latex has the potential to be used in the development of therapeutic modalities for the possible treatment, cure and prevention of HPV related cervical cancer.

HPV-Related Papillary Lesions of the Oral Mucosa: A Review

Human papillomaviruses (HPVs) are causative of a group of clinically papillary lesions. The HPV-related lesions of the oral cavity include squamous papilloma, condyloma acuminatum, verruca vulgaris, and multifocal epithelial hyperplasia. Benign entities, such as verruciform xanthoma or giant cell fibroma, as well as malignancies, such as papillary squamous cell carcinoma and verrucous carcinoma, may be considered in the clinical and/or histologic differential diagnoses of these lesions. Mechanisms of infection, epidemiology, clinical presentations, histologic features, and differential diagnoses of the HPV-related oral pathologies are discussed. Current concepts of viral transmission, especially as pertaining to lesions in pediatric patients, and the impacts of HPV vaccination are reviewed.

The molecular biology and HPV drug responsiveness of cynomolgus macaque papillomaviruses support their use in the development of a relevant in vivo model for antiviral drug testing

Due to the extreme tissue and species restriction of the papillomaviruses (PVs), there is a great need for animal models that accurately mimic PV infection in humans for testing therapeutic strategies against human papillomaviruses (HPVs). In this study, we present data that demonstrate that in terms of gene expression during initial viral DNA amplification, Macaca fascicularis PV (MfPV) types 5 and 8 appear to be similar to mucosal oncogenic HPVs, while MfPV1 (isolated from skin) resembles most high-risk cutaneous beta HPVs (HPV5). Similarities were also observed in replication properties during the initial amplification phase of the MfPV genomes. We demonstrate that high-risk mucosal HPV-specific inhibitors target the transient replication of the MfPV8 genomes, which indicates that similar pathways are used by the high-risk HPVs and MfPVs during their genome replication. Taking all into account, we propose that Macaca fascicularis may serve as a highly relevant model for preclinical tests designed to evaluate therapeutic strategies against HPV-associated lesions.

Anti-Cancer Vaccine for HPV-Associated Neoplasms: Focus on a Therapeutic HPV Vaccine Based on a Novel Tumor Antigen Delivery Method Using Endogenously Engineered Exosomes

Some human papillomavirus (HPV) genotypes are universally recognized as major etiological agents not only of ano-genital tumors but also of head and neck cancers, which show increasing incidence. The evaluation of current and future therapeutic approaches against HPV-induced tumors is a global health priority, despite an effective prophylactic vaccine against 7 of the 12 genotypes involved in the etiology of tumors being currently available. In this review, we present the main anti-HPV therapeutic approaches in clinical experimentation, with a focus on a novel tumor antigen delivery method using engineered exosomes, that we recently developed. Our system allows the induction of an efficient unrestricted cytotoxic T lymphocyte (CTL) immune response against the HPV16-E7 tumor-associated antigen, with the formation of endogenously engineered exosomes, i.e., nanovesicles spontaneously released by all cell types. Immunogenic exosomes are uploaded with HPV16-E7 due to the fusion with a unique exosome-anchoring protein referred to as Nefmut. Intramuscular injection of a DNA vector expressing the fusion protein generates exosomes sufficiently immunogenic to elicit a potent anti-16E7 CTL immune response. The approach is described here and the advantages over other existing methodologies are reported.

TaME-seq: An efficient sequencing approach for characterisation of HPV genomic variability and chromosomal integration

HPV genomic variability and chromosomal integration are important in the HPV-induced carcinogenic process. To uncover these genomic events in an HPV infection, we have developed an innovative and cost-effective sequencing approach named TaME-seq (tagmentation-assisted multiplex PCR enrichment sequencing). TaME-seq combines tagmentation and multiplex PCR enrichment for simultaneous analysis of HPV variation and chromosomal integration, and it can also be adapted to other viruses. For method validation, cell lines (n = 4), plasmids (n = 3), and HPV16, 18, 31, 33 and 45 positive clinical samples (n = 21) were analysed. Our results showed deep HPV genome-wide sequencing coverage. Chromosomal integration breakpoints and large deletions were identified in HPV positive cell lines and in one clinical sample. HPV genomic variability was observed in all samples allowing identification of low frequency variants. In contrast to other approaches, TaME-seq proved to be highly efficient in HPV target enrichment, leading to reduced sequencing costs. Comprehensive studies on HPV intra-host variability generated during a persistent infection will improve our understanding of viral carcinogenesis. Efficient identification of both HPV variability and integration sites will be important for the study of HPV evolution and adaptability and may be an important tool for use in cervical cancer diagnostics.

Biodegradable andrographolide-eluting nanofibrous membranes for the treatment of cervical cancer

BACKGROUND

In this study, we developed biodegradable andrographolide (AG)-eluting nanofibrous mats and evaluated their efficacy in treating cervical cancer.

MATERIALS AND METHODS

Membranes of two different poly[(d,l)-lactide-co-glycolide] (PLGA)-to-AG ratios (6:1 and 3:1) were prepared via electrospinning technology. The liberation behavior of AG was evaluated. A cervical cancer model with C57BL/6J mice was created and employed for an in vivo efficacy assessment of the drug-eluting nanofibers. Twelve mice with cervical cancer were stochastically divided into three different groups (four animals per group): group A received no treatment as the control, group B was treated with pure PLGA mats, and group C was treated with AG-loaded nanofibrous membranes. The changes in tumor sizes were recorded.

RESULTS

All membranes eluted high concentrations of AG at the target area for three weeks, while the systemic drug concentration in the blood remained low. Histological analysis showed no obvious tissue inflammation. Compared with the mice in groups A and B, the tumor size of the mice in group C decreased with time until day 25, when the daily drug concentration reduced to 3 µg/mL.

CONCLUSION

Biodegradable nanofibers with a sustainable release of AG exhibit adequate efficacy and durability for the treatment of mice with cervical cancer.

Prevalence and incidence of genital warts and cervical Human Papillomavirus infections in Nigerian women

BACKGROUND

Genital warts are important causes of morbidity and their prevalence and incidence can be used to evaluate the impact of HPV vaccination in a population.

METHODS

We enrolled 1020 women in a prospective cohort study in Nigeria and followed them for a mean (SD) of 9 (4) months. Nurses conducted pelvic examinations and collected ectocervical samples for HPV testing. We used exact logistic regression models to identify risk factors for genital warts.

RESULTS

The mean age of study participants was 38 years, 56% (535/962) were HIV-negative and 44% (427/962) were HIV-positive. Prevalence of genital warts at enrolment was 1% (4/535) among HIV-negative women, and 5% (23/427) among HIV-positive women. Of 614 women (307 HIV negative and 307 HIV positive women) for whom we could compute genital wart incidence, it was 515 (95% CI:13-2872) per 100,000 person-years in HIV-negative and 1370 (95% CI:283-4033) per 100,000 person-years in HIV-positive women. HIV was associated with higher risk of prevalent genital warts (OR:7.14, 95% CI:2.41-28.7, p < 0.001) while higher number of sex partners in the past year was associated with increased risk of incident genital warts (OR:2.86, 95% CI:1.04-6.47. p = 0.04). HPV11 was the only HPV associated with prevalent genital warts in this population (OR:8.21, 95% CI:2.47-27.3, p = 0.001).

CONCLUSION

Genital warts are common in Nigeria and our results provide important parameters for monitoring the impact of future HPV vaccination programs in the country. HIV infection and number of sexual partners in past year were important risk factors for prevalent and incident genital warts respectively.

Vaccine synergy with virus-like particle and immune complex platforms for delivery of human papillomavirus L2 antigen

Diverse HPV subtypes are responsible for considerable disease burden worldwide, necessitating safe, cheap, and effective vaccines. The HPV minor capsid protein L2 is a promising candidate to create broadly protective HPV vaccines, though it is poorly immunogenic by itself. To create highly immunogenic and safe vaccine candidates targeting L2, we employed a plant-based recombinant protein expression system to produce two different vaccine candidates: L2 displayed on the surface of hepatitis B core (HBc) virus-like particles (VLPs) or L2 genetically fused to an immunoglobulin capable of forming recombinant immune complexes (RIC). Both vaccine candidates were potently immunogenic in mice, but were especially so when delivered together, generating very consistent and high antibody titers directed against HPV L2 (>1,000,000) that correlated with virus neutralization. These data indicate a novel immune response synergy upon co-delivery of VLP and RIC platforms, a strategy that can be adapted generally for many different antigens.

Viral metagenomics updated the prevalence of human papillomavirus types in anogenital warts

To investigate the composition of human papillomavirus (HPV) types in anogenital warts (AGWs), viral nucleic acid in 110 AGWs, pooled into 11 specimen pools, were subjected to viral metagenomic analysis. After finding HPV7 in AGWs, conventional PCR screening was performed for HPV7 in other 190 individual AGW specimens. Viral metagenomic results indicated that 29 different types of HPV were recovered, with HPV11 and HPV6 showing the highest proportion of sequence reads. HPV7 was detected in 7 of 11 pools, 5 of which contained abundant HPV7 sequence reads. 24 complete genomes of HPV were acquired in viral metagenomic analysis, including 5 HPV7 genomes, based on which phylogenetic analysis and pairwise sequence comparison were conducted. PCR screening for HPV7 in other 190 individual AGW specimens revealed 25 positive cases (13.16%), of which the amplified fragments were sequenced and confirmed to be HPV7 sequences. Although HPV7 was generally found in hand warts and recently also in warts in toe webs, our data suggested that the role of HPV7 in AGW should be considered in the future clinical test and vaccine development for AGWs.

Methylation of p16 ink4a promoter is independent of human papillomavirus DNA physical state: a comparison between cervical pre-neoplastic and neoplastic samples

BACKGROUND Epigenetic modifications in host cells, like p16 ink4a methylation, have been considered as putative complementary mechanisms for cancer development. Because only a small proportion of infected women develop cervical cancer, other factors might be involved in carcinogenesis, either independently or in association with high-risk human papillomavirus (HR-HPV) infections, including epigenetic factors. OBJECTIVES We hypothesised that p16 ink4a methylation might have a role in cancer development driven by HPV16, mainly in the presence of intact E1/E2 genes. Thus, our objectives were to assess the status of p16 ink4a methylation and the HPV16 E1/E2 integrity in samples in different stages of cervical diseases. METHODS Presence of HPV16 was determined by E6 type-specific polymerase chain reaction (PCR). Methylation status of the p16 ink4a promoter was assessed by methylation-specific PCR in 87 cervical specimens comprising 29 low-grade (LSIL), 41 high-grade (HSIL) lesions, and 17 cervical cancers (CC). Characterisation of E1 and E2 disruption (as an indirect indicator of the presence of episomal viral DNA) was performed by PCR amplifications. FINDINGS We observed a significantly increased trend (nptrend = 0.0320) in the proportion of methylated p16 ink4a in cervical samples during cancer development. Concomitant E1 and E2 disruptions were the most frequent pattern found in all groups: CC (76%), HSIL (54%), and LSIL (73%). No statistically significant differences between p16 ink4a methylation and E1/E2 integrity, in histological groups, was observed. MAIN CONCLUSIONS There was an increase in methylation of the p16 ink4a promoter from pre-neoplastic lesions to cancer. Additionally, a high frequency of E1/E2 disruptions in LSIL/HSIL suggested that viral DNA integration was an early event in cervical disease. Moreover, the methylation status was apparently independent of HPV16 integrity.

HPV vaccines and lupus: current approaches towards preventing adverse immune cross-reactivity

INTRODUCTION

If not properly treated, human papillomavirus (HPV) infection may evolve from a common sexually transmitted disease to genital warts and cervical cancer. Various prophylactic HPV vaccines (HPVv), approved to reduce the incidence of the infection, have been found to be effective and safe; however, accounts of post-vaccination autoimmune phenomena, including systemic lupus erythematosus (SLE), have been reported in genetically susceptible individuals.

AREAS COVERED

Infectious agents play a role in breaking the immunologic tolerance to self-antigens, resulting in autoimmune events. There is molecular evidence supporting the involvement of HPV in SLE, with a high prevalence of L1 HPV peptide homology to proteins being associated with SLE. Therefore, approaches in vaccine preparations aiming to prevent adverse immune cross-reactivity are sought. Performing a broad search of the literature, we review the association between SLE, HPV, and HPVv, with a focus on the mechanisms of molecular mimicry and cross-reactivity, and the approaches currently being elaborated towards preventing such phenomena.

EXPERT COMMENTARY

The advantages of using low-similarity peptide antigens may be two-fold, abolishing the risk of cross-reactivity and eliminating the vaccine adjuvantation procedure. Vaccines based on pathogen unique sequences would provide effective vaccine preparation while curbing the risk for the human host.

Quantification of HPV16 E6/E7 mRNA Spliced Isoforms Viral Load as a Novel Diagnostic Tool for Improving Cervical Cancer Screening

High-risk human papillomaviruses (HPVs) have been identified as the main contributors to cervical cancer. Despite various diagnostic tools available, including the predominant Papanicolaou test (Pap test), technical limitations affect the efficiency of cervical cancer screening. The aim of this study was to evaluate the diagnostic performance of spliced HPV16 E6/E7 mRNA viral loads (VL) for grade 2 or higher cervical intraepithelial neoplasia diagnosis. A new dedicated (quantitative reverse transcription polymerase chain reaction) qRT-PCR assay was developed, allowing selective quantification of several HPV16 E6/E7 mRNA: Full length (FL) with or without all or selected spliced forms (total E6/E7 mRNA corresponding to SP + E6^E7 mRNA (T), + spliced E6/E7 mRNA containing intact E7 ORF (SP), and E6/E7 mRNA containing disrupted E6 and E7 ORFs calculated by the following subtraction T-SP (E6^E7)). Twenty HPV16 DNA and mRNA positive uterine cervical smears representative of all cytological and histological stages of severity were tested. We have shown that all E6/E7 mRNA isoforms expression levels were significantly increased in high grade cervical lesions. Statistical analysis demonstrated that the SP-E6/E7 VL assay exhibited: (i) The best diagnostic performance for identification of both cervical intraepithelial neoplasia (CIN)2+ (90% (56–100) sensitivity and specificity) and CIN3+ (100% (72–100) sensitivity and 79% (49–95) specificity) lesions; (ii) a greater sensitivity compared to the Pap test for CIN2+ lesions detection (80% (44–97)); (iii) a predictive value of the histological grade of cervical lesions in 67% of atypical squamous cells of unknown significance (ASC-US) and 100% of low-grade (LSIL) patients. Overall, these results highlight the value of SP-E6/E7 mRNA VL as an innovative tool for improving cervical cancer screening.