Human papillomavirus-16 E5 protein: oncogenic role and therapeutic value

A bacterially expressed triple-type chimeric vaccine against human papillomavirus types 51, 69, and 26

Persistent infection of high-risk human papillomavirus (HPV) is a leading cause of some cancers, including cervical cancer. However, with over 20 carcinogenic HPV types, it is difficult to design a multivalent vaccine that can offer complete protection. Here, we describe the design and optimization of a HPV51/69/26 triple-type chimeric virus-like particle (VLP) for vaccine development. Using E. coli and a serial N-terminal truncation strategy, we created double- and triple-type chimeric VLPs through loop-swapping at equivalent surface loops. The lead candidate, H69-51BC-26FG, conferred similar particulate properties as that of its parental VLPs and comparable immunogenicity against HPV51, -69 and -26. When produced in a GMP-like facility, these H69-51BC-26FG VLPs were verified to have excellent qualities for the development of a multivalent HPV vaccine. This study showcases an amenable way to create a single VLP using type-specific epitope clustering for the design of a triple-type vaccine.

Role of HPV16 E1 in cervical carcinogenesis

Cervical cancer is the fourth most common cancer in women worldwide. More than 90% of cases are caused by the human papillomavirus (HPV). Vaccines developed only guard against a few HPV types and do not protect people who have already been infected. HPV is a small DNA virus that infects the basal layer of the stratified epithelium of the skin and mucosa through small breaks and replicates as the cells differentiate. The mucosal types of HPV can be classified into low-risk and high-risk groups, based on their association with cancer. Among HPV types in high-risk group, HPV type 16 (HPV-16) is the most common, causing 50% of all cancer cases. HPV infection can occur as transient or persistent infections, based on the ability of immune system to clear the virus. Persistent infection is characterized by the integration of HPV genome. HPV-16 exhibits a different integration pattern, with only 50% reported to be integrated at the carcinoma stage. Replication of the HPV genome depends on protein E1, an ATP-dependent helicase. E1 is essential for the amplification of the viral episome in infected cells. Previous studies have shown that E1 does not only act as a helicase protein but is also involved in recruiting and interacting with other host proteins. E1 has also been deemed to drive host cell proliferation. Recent studies have emphasized the emerging role of HPV E1 in cervical carcinogenesis. In this review, a possible mechanism by which E1 drives cell proliferation and oncogenesis will be discussed.

It Takes Two to Tango: A Review of Oncogenic Virus and Host Microbiome Associated Inflammation in Head and Neck Cancer

Simple Summary

Certain viruses, specifically, human papillomavirus (HPV) and Epstein–Barr virus (EBV), have been linked with the development of head and neck cancer. In this study, we review the mechanisms by which (these) viruses lead to cellular transformation and a chronic inflammatory state. Given that the head and neck host a rich microbiome (which itself is intrinsically linked to inflammation), we scrutinize the literature to highlight the interplay between viruses, cellular transformation, inflammation, and the local host microbiome in head and neck cancer.

Abstract

While the two primary risk factors for head and neck squamous cell carcinoma (HNSCC) are alcohol and tobacco, viruses account for an important and significant upward trend in HNSCC incidence. Human papillomavirus (HPV) is the causative agent for a subset of oropharyngeal squamous cell carcinoma (OPSCC)—a cancer that is impacting a rapidly growing group of typically middle-aged non-smoking white males. While HPV is a ubiquitously present (with about 1% of the population having high-risk oral HPV infection at any one time), less than 1% of those infected with high-risk strains develop OPSCC—suggesting that additional cofactors or coinfections may be required. Epstein–Barr virus (EBV) is a similarly ubiquitous virus that is strongly linked to nasopharyngeal carcinoma (NPC). Both of these viruses cause cellular transformation and chronic inflammation. While dysbiosis of the human microbiome has been associated with similar chronic inflammation and the pathogenesis of mucosal diseases (including OPSCC and NPC), a significant knowledge gap remains in understanding the role of bacterial-viral interactions in the initiation, development, and progression of head and neck cancers. In this review, we utilize the known associations of HPV with OPSCC and EBV with NPC to investigate these interactions. We thoroughly review the literature and highlight how perturbations of the pharyngeal microbiome may impact host-microbiome-tumor-viral interactions—leading to tumor growth.

Development of HPV16,18,31,45 E5 and E7 peptides-based vaccines predicted by immunoinformatics tools

Objectives

Viral oncoproteins are ideal targets in therapeutic vaccines for functional inhibition of human papillomaviruses (HPVs). Herein, we designed the peptide constructs derived from E5 and E7 oncoproteins of high-risk HPV types 16, 18, 31 and 45 using the bioinformatics tools and investigated their potency in mice.

Results

The framework of the combined in silico/in vivo analysis included (1) to determine physicochemical properties of the designed constructs, (2) to identify potential IFN-γ-inducing epitopes, (3) to assess allergenicity, (4) to recognize linear and discontinuous B cell epitopes using modeling and validation of 3D structure of the designed constructs, and (5) to evaluate immune responses and tumor growth in vivo. Our in silico data determined high potency of the HPV_16,18,31,45 E5 and HPV_16,18,31,45 E7 peptides for trigger B- and T-cell responses, and IFN-γ secretion. In vivo study indicated that the mixture of E5 and E7 immunodominant peptides from four types of high-risk HPV could induce Th1 immune response, and protect completely mice against TC-1 tumor cells.

Conclusion

Generally, the combined in silico/in vivo approaches showed the ability of the designed E5 and E7 peptide constructs from four major high-risk HPV types for development of therapeutic vaccines.

Electronic supplementary material

The online version of this article (10.1007/s10529-020-02792-6) contains supplementary material, which is available to authorized users.

Unbiased Identification of T-Cell Receptors Targeting Immunodominant Peptide-MHC Complexes for T-Cell Receptor Immunotherapy

T-cell receptor (TCR) immunotherapy uses T cells engineered with new TCRs to enable detection and killing of cancer cells. Efficacy of TCR immunotherapy depends on targeting antigenic peptides that are efficiently presented by the best-suited major histocompatibility complex (MHC) molecules of cancer cells. However, efficient strategies are lacking to easily identify TCRs recognizing immunodominant peptide-MHC (pMHC) combinations utilizing any of the six possible MHC class I alleles of a cancer cell. We generated an MHC cell library and developed a platform approach to detect, isolate, and re-express TCRs specific for immunodominant pMHCs. The platform approach was applied to identify a human papillomavirus (HPV16) oncogene E5-specific TCR, recognizing a novel, naturally processed pMHC (HLA-B*15:01) and a cytomegalovirus-specific TCR targeting an immunodominant pMHC (HLA-B*07:02). The platform provides a useful tool to isolate in an unbiased manner TCRs specific for novel and immunodominant pMHC targets for use in TCR immunotherapy.

Detection and Type-Distribution of Human Papillomavirus in Vulva and Vaginal Abnormal Cytology Lesions and Cancer Tissues from Thai Women

Vulva and Vaginal cancers are rare among all gynecological cancers worldwide, including Thailand, and typically affect women in later life. Persistent high risk human papillomavirus (HR-HPV) infection is one of several important causes of cancer development. In this study, we focused on HPV investigation and specific type distribution from Thai women with abnormality lesions and cancers of the vulva and Vaginal. A total of ninety paraffin-embedded samples of vulva and Vaginal abnormalities and cancer cells with histologically confirmed were collected from Thai women, who were diagnosed in 2003-2012 at the National Cancer Institute, Thailand. HPV DNA was detected and genotyped using polymerase chain reaction and enzyme immunoassay with GP5+/ bio 6+ consensus specific primers and digoxigenin-labeled specific oligoprobes, respectively. The human β-globin gene was used as an internal control. Overall results represented that HPV frequency was 16/34 (47.1%) and 8/20 (40.0%) samples of vulva with cancer and abnormal cytology lesions, respectively, while, 3/5 (60%) and 16/33 (51.61%) samples of Vaginal cancer and abnormal cytology lesions, respectively, were HPV DNA positive. Single HPV type and multiple HPV type infection could be observed in both type of cancers and abnormal lesion samples in the different histological categorizes. HPV16 was the most frequent type in all cancers and abnormal cytology lesions, whereas HPV 18 was less frequent and could be detected as co-infection with other high risk HPV types. In addition, low risk types such as HPV 6, 11 and 70 could be detected in Vulva cancer and abnormal cytology lesion samples, whereas, all Vaginal cancer samples exhibited only high risk HPV types; HPV 16 and 31. In conclusion, from our results in this study we suggest that women with persistent high risk HPV type infection are at risk of developing vulva and Vaginal cancers and HPV 16 was observed at the highest frequent both of these, similar to the cervical cancer cases. Although the number of samples in this study was limited and might not represent the overall incidence and prevalence in Thai women, but the baseline data are of interest and suggest further study for primary cancer screening and/or developing the efficiency of prophylactic HPV vaccines in Thailand.

MicroRNA-331-3p Suppresses Cervical Cancer Cell Proliferation and E6/E7 Expression by Targeting NRP2

Aberrant expression of microRNAs (miRNAs) is involved in the development and progression of various types of cancers. In this study, we investigated the role of miR-331-3p in cell proliferation and the expression of keratinocyte differentiation markers of uterine cervical cancer cells. Moreover, we evaluated whether neuropilin 2 (NRP2) are putative target molecules that regulate the human papillomavirus (HPV) related oncoproteins E6 and E7. Cell proliferation in the human cervical cancer cell lines SKG-II, HCS-2, and HeLa was assessed using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. Cellular apoptosis was measured using the TdT-mediated dUTP nick end labeling (TUNEL) and Annexin V assays. Quantitative RT-PCR was used to measure the messenger RNA (mRNA) expression of the NRP2, E6, E7, p63, and involucrin (IVL) genes. A functional assay for cell growth was performed using cell cycle analyses. Overexpression of miR-331-3p inhibited cell proliferation, and induced G2/M phase arrest and apoptosis in SKG-II, HCS-2 and HeLa cells. The luciferase reporter assay of the NRP2 3′-untranslated region revealed the direct regulation of NRP2 by miR-331-3p. Gene expression analyses using quantitative RT-PCR in SKG-II, HCS-2, and HeLa cells overexpressing miR-331-3p or suppressing NRP2 revealed down-regulation of E6, E7, and p63 mRNA and up-regulation of IVL mRNA. Moreover, miR-331-3p overexpression was suppressed NRP2 expression in protein level. We showed that miR-331-3p and NRP2 were key effectors of cell proliferation by regulating the cell cycle, apoptosis. NRP-2 also regulates the expression of E6/E7 and keratinocyte differentiation markers. Our findings suggest that miR-331-3p has an important role in regulating cervical cancer cell proliferation, and that miR-331-3p may contribute to keratinocyte differentiation through NRP2 suppression. miR-331-3p and NRP2 may contribute to anti-cancer effects.

GW627368X inhibits proliferation and induces apoptosis in cervical cancer by interfering with EP4/EGFR interactive signaling

PGE2, the major product of cyclooxygenases implicated in carcinogenesis, is significantly upregulated in cervical cancer. PGE2 via prostanoid receptor EP4 stimulates proliferation and motility while inhibiting apoptosis and immune surveillance. It promotes angiogenesis by stimulating the production of pro-angiogenic factors. The present study demonstrates GW627368X, a highly selective competitive EP4 antagonist, which hinders cervical cancer progression by inhibiting EP4/epithelial growth factor receptor (EGFR) interactive signaling. GW627368X reduced protein kinase A (PKA) phosphorylation which in turn leads to decreased cAMP response element-binding protein (CREB) activation. Decreased PKA phosphorylation also directly enhanced Bax activity and in part reduced glycogen synthase kinase 3 (GSK3)β phosphorylation. Owing to the interactive signaling between EP4 and EGFR, GW627368X lowered EGFR phosphorylation in turn reducing Akt, mitogen-activated protein kinase (MAPK) and GSK3β activity significantly. Sublethal dose of GW627368X was found to reduce the nuclear translocation of β-catenin in a time dependent manner along with time-dependent decrease in cytoplasmic as well as whole-cell β-catenin. Decreased CREB and β-catenin transcriptional activity restricts the aberrant transcription of key genes like EP4, cyclooxygenase (COX)-2, vascular endothelial growth factor and c-myc, which ultimately control cell survival, proliferation and angiogenesis. Reduced activity of EGFR resulted in enhanced expression of 15-hydroxyprostaglandin dehydrogenase increasing PGE2 degradation thereby blocking a positive feedback loop. In xenograft model, dose-dependent decrease in cancer proliferation was observed characterized by reduction in tumor mass and volume and a marked decrease in Ki67 expression. A diminished CD31 specific staining signified decreased tumor angiogenesis. Reduced expression of pAkt, pMAPK, pEGFR and COX-2 validated in vitro results. GW627368X therefore effectively inhibits tumor survival, motility, proliferation and angiogenesis by blocking EP4/EGFR interactive signaling. EP4 is a potent therapeutic target in cervical cancer and can be explored in combination with conventional therapies to attain superior outcomes and to overcome complications associated with organ toxicities, therapeutic resistance and disease relapse.

Current therapeutic vaccination and immunotherapy strategies for HPV-related diseases

Carcinomas of the anogenital tract, in particular cervical cancer, remains one of the most common cancers in women, and represent the most frequent gynecological malignancies and the fourth leading cause of cancer death in women worldwide. Human papillomavirus (HPV)-induced lesions are immunologically distinct in that they express viral antigens, which are necessary to maintain the cancerous phenotype. The causal relationship between HPV infection and anogenital cancer has prompted substantial interest in the development of therapeutic vaccines against high-risk HPV types targeting the viral oncoproteins E6 and E7. This review will focus on the most recent clinical trials for immunotherapies for mucosal HPV-induced lesions as well as emerging therapeutic strategies that have been tested in pre-clinical models for HPV-induced diseases. Progress in peptide- and protein-based vaccines, DNA-based vaccines, viral/bacterial vector-based vaccines, immune checkpoint inhibition, immune response modifiers, and adoptive cell therapy for HPV will be discussed.

The cancer genome: from structure to function

The 2014 joint meeting of the International Society for Cellular Oncology (ISCO) and the European Workshop on Cytogenetics and Molecular Genetics of Solid Tumors (EWCMST), organized by Nick Gilbert, Juan Cigudosa and Bauke Ylstra, was held from 11 to 14 May in Malaga, Spain. Since the previous meeting in 2012, the ever increasing availability of new sequencing technologies has enabled the analysis of cancer genomes at an increasingly greater detail. In addition to structural changes in the genome (i.e., translocations, deletions, amplifications), frequent mutations in important regulatory genes have been found to occur, as also frequent alterations in a large number of epigenetic factors. The challenge now is to relate structural changes in cancer genomes to the underlying disease mechanisms and to reveal opportunities for the design of novel (targeted) therapies. During the meeting, various topics related to these challenges and opportunities were addressed, including those dealing with functional genomics, genome instability, biomarkers and diagnostics, cancer genetics and epigenomics. Special attention was paid to therapy-driven cancer evolution (keynote lecture) and relationships between DNA repair, cancer and ageing (Prof. Ploem lecture). Based on the information presented at the meeting, several aspects of the cancer genome and its functional implications are provided in this report.

Therapeutic Vaccine Strategies against Human Papillomavirus

High-risk types of human papillomavirus (HPV) cause over 500,000 cervical, anogenital and oropharyngeal cancer cases per year. The transforming potential of HPVs is mediated by viral oncoproteins. These are essential for the induction and maintenance of the malignant phenotype. Thus, HPV-mediated malignancies pose the unique opportunity in cancer vaccination to target immunologically foreign epitopes. Therapeutic HPV vaccination is therefore an ideal scenario for proof-of-concept studies of cancer immunotherapy. This is reflected by the fact that a multitude of approaches has been utilized in therapeutic HPV vaccination design: protein and peptide vaccination, DNA vaccination, nanoparticle- and cell-based vaccines, and live viral and bacterial vectors. This review provides a comprehensive overview of completed and ongoing clinical trials in therapeutic HPV vaccination (summarized in tables), and also highlights selected promising preclinical studies. Special emphasis is given to adjuvant science and the potential impact of novel developments in vaccinology research, such as combination therapies to overcome tumor immune suppression, the use of novel materials and mouse models, as well as systems vaccinology and immunogenetics approaches.

Identification of promiscuous HPV16-derived T helper cell epitopes for therapeutic HPV vaccine design

Cervical carcinoma and several other human papillomavirus (HPV)-induced malignancies are a global public health problem, thus novel treatment modalities are urgently needed. Immunotherapy is an attractive option for treatment of HPV infection and HPV-mediated premalignant and malignant lesions. However, previous approaches--focusing on the induction of cytotoxic CD8+ T cells (CTLs)--have as yet not yielded clinical successes. Since CD4+ T cells have been shown to be crucial for the induction and maintenance of CTL responses, and more recently to be also important for direct anti-tumor immunity, human leukocyte antigen (HLA) class II-restricted epitopes are intensively investigated to improve the efficacy of peptide-based HPV immunotherapy. We here present an approach to identify promiscuous HPV16-derived CD4+ T helper epitopes, which are capable of inducing T cell immunity in a large proportion of the population. To this end, we combined HLA class II epitope prediction servers with in vitro immunological evaluation to identify HPV16 E2-, E5-, E6-, and E7-derived CD4+ T cell epitopes. Candidate selected HPV16-derived epitopes were found to be restricted by up to nine HLA-DR molecules. Furthermore, they were found to induce frequent and robust HPV16 peptide-specific Th1 responses in healthy donors, as monitored by interferon (IFN)-γ ELISPOT and cytokine secretion assays. Moreover, these selected peptides also induced specific IFN-γ T cell responses in blood from HPV16+ CIN2/3 and cervical carcinoma patients. We thus conclude that the identified T helper epitopes are valuable candidates for the development of a comprehensive therapeutic HPV vaccine.

Papillomavirus-associated squamous skin cancers following transplant immunosuppression: one Notch closer to control

The frequent occurrence of cutaneous squamous cell carcinomas (SCCs) containing weakly tumorigenic human papillomaviruses (HPVs) following iatrogenic immunosuppression for organ transplantation remains incompletely understood. Here we address this problem in the light of recent insights into (1) the association of low-risk β-HPVs with skin SCCs in the rare genetic syndromes of epidermodysplasia verruciformis and xeroderma pigmentosum, (2) the frequent recovery of post-transplant tumor control on substituting calcineurin-inhibitory with mTOR-inhibitory immunosuppression, (3) the unexpectedly favorable prognosis of node-positive SCCs containing high-risk α-HPVs originating in the activated immune niche of the oropharynx, (4) the rapid occurrence of HPV-negative SCCs in ultraviolet (UV)-damaged skin of melanoma patients receiving Raf-inhibitory drugs, and (5) the selective ability of β-HPV E6 oncoproteins to inhibit Notch tumor-suppressive signaling in cutaneous and mesenchymal tissues. The crosstalk so implied between oncogenic UV-induced mutations, defective host immunity, and β-HPV-dependent stromal-epithelial signaling suggests that immunosuppressants such as calcineurin inhibitors intensify mitogenic signalling in TP53-mutant keratinocytes while also abrogating immune-dependent Notch-mediated tumor repression. This emerging interplay between solar damage, viral homeostasis and immune control makes it timely to reappraise strategies for managing skin SCCs in transplant patients.

ErbB1-4-dependent EGF/neuregulin signals and their cross talk in the central nervous system: pathological implications in schizophrenia and Parkinson's disease

Ligands for ErbB1-4 receptor tyrosine kinases, such as epidermal growth factor (EGF) and neuregulins, regulate brain development and function. Thus, abnormalities in their signaling are implicated in the etiology or pathology of schizophrenia and Parkinson's disease. Among the ErbB receptors, ErbB1, and ErbB4 are expressed in dopamine and GABA neurons, while ErbB1, 2, and/or 3 are mainly present in oligodendrocytes, astrocytes, and their precursors. Thus, deficits in ErbB signaling might contribute to the neurological and psychiatric diseases stemming from these cell types. By incorporating the latest cancer molecular biology as well as our recent progress, we discuss signal cross talk between the ErbB1-4 subunits and their neurobiological functions in each cell type. The potential contribution of virus-derived cytokines (virokines) that mimic EGF and neuregulin-1 in brain diseases are also discussed.