Feline SCCs of the Head and Neck Display Partial Epithelial-Mesenchymal Transition and Harbor Stem Cell-like Cancer Cells.

Squamous cell carcinoma of the head and neck (HNSCC) is a malignant cancer disease in humans and animals. There is ample evidence that the high plasticity of cancer cells, i.e., their ability to switch from an epithelial to a mesenchymal, endothelial, and stem cell-like phenotype, chiefly contributes to progression, metastasis, and multidrug resistance of human HNSCCs. In feline HNSCC, the field of cancer cell plasticity is still unexplored. In this study, fourteen feline HNSCCs with a known feline papillomavirus (FPV) infection status were subjected to histopathological grading and subsequent screening for expression of epithelial, mesenchymal, and stem cell markers by immunohistochemistry (IHC) and immunofluorescence staining (IF). Irrespective of the FPV infection status, all tumors except one corresponded to high-grade, invasive lesions and concurrently expressed epithelial (keratins, E-cadherin, ß-catenin) and mesenchymal (vimentin, N-cadherin, CD146) proteins. This finding is indicative for partial epithelial-mesenchymal transition (pEMT) events in the lesions, as similarly described for human HNSCCs. IF double staining revealed the presence of CD44/CD271 double-positive cells notably within the tumors' invasive fronts that likely correspond to cancer stem cells. Taken together, the obtained findings suggest that feline HNSCCs closely resemble their human counterparts with respect to tumor cell plasticity.

CRISPR/Cas9-Mediated Targeting of BPV-1-Transformed Primary Equine Sarcoid Fibroblasts.

Equine sarcoids (EqS) are fibroblast-derived skin tumors associated with bovine papillomavirus 1 and 2 (BPV-1 and -2). Based on Southern blotting, the BPV-1 genome was not found to be integrated in the host cell genome, suggesting that EqS pathogenesis does not result from insertional mutagenesis. Hence, CRISPR/Cas9 implies an interesting tool for selectively targeting BPV-1 episomes or genetically anchored suspected host factors. To address this in a proof-of-concept study, we confirmed the exclusive episomal persistence of BPV-1 in EqS using targeted locus amplification (TLA). To investigate the CRISPR/Cas9-mediated editing of BPV-1 episomes, primary equine fibroblast cultures were established and characterized. In the EqS fibroblast cultures, CRISPR-mediated targeting of the episomal E5 and E6 oncogenes as well as the BPV-1 long control region was successful and resulted in a pronounced reduction of the BPV-1 load. Moreover, the deletion of the equine Vimentin (VIM), which is highly expressed in EqS, considerably decreased the number of BPV-1 episomes. Our results suggest CRISPR/Cas9-based gene targeting may serve as a tool to help further unravel the biology of EqS pathogenesis.

Immunotherapy of Equine Sarcoids-From Early Approaches to Innovative Vaccines.

Horses and other equid species are frequently affected by bovine papillomavirus type 1 and/or 2 (BPV1, BPV2)-induced skin tumors termed sarcoids. Although sarcoids do not metastasize, they constitute a serious health problem due to their BPV1/2-mediated resistance to treatment and propensity to recrudesce in a more severe, multiple form following accidental or iatrogenic trauma. This review provides an overview on BPV1/2 infection and associated immune escape in the equid host and presents early and recent immunotherapeutic approaches in sarcoid management.

Detection of Equine Papillomaviruses and Gamma-Herpesviruses in Equine Squamous Cell Carcinoma.

Squamous cell carcinoma (SCC) seriously compromises the health and welfare of affected horses. Although robust evidence points to equine papillomavirus type 2 (EcPV2) causing genital lesions, the etiopathogenesis of equine SCC is still poorly understood. We screened a series of SCCs from the head-and-neck (HN), (peri-)ocular and genital region, and site-matched controls for the presence of EcPV2-5 and herpesvirus DNA using type-specific EcPV PCR, and consensus nested herpesvirus PCR followed by sequencing. EcPV2 DNA was detected in 45.5% of HN lesions, 8.3% of (peri-)ocular SCCs, and 100% of genital tumors, whilst control samples from tumor-free horses except one tested EcPV-negative. Two HNSCCs harbored EcPV5, and an ocular lesion EcPV4 DNA. Herpesvirus DNA was detected in 63.6%, 66.6%, 47.2%, and 14.2% of horses with HN, ocular, penile, and vulvar SCCs, respectively, and mainly identified as equine herpesvirus 2 (EHV2), 5 (EHV5) or asinine herpesvirus 5 (AsHV5) DNA. In the tumor-free control group, 9.6% of oral secretions, 46.6% of ocular swabs, 47% of penile samples, and 14.2% of vaginal swabs scored positive for these herpesvirus types. This work further highlights the role of EcPV2 as an oncovirus and is the first to provide information on the prevalence of (gamma-)herpesviruses in equine SCCs.

Papillomavirus-like Particles in Equine Medicine.

Papillomaviruses (PVs) are a family of small DNA tumor viruses that can induce benign lesions or cancer in vertebrates. The observation that animal PV capsid-proteins spontaneously self-assemble to empty, highly immunogenic virus-like particles (VLPs) has led to the establishment of vaccines that efficiently protect humans from specific PV infections and associated diseases. We provide an overview of PV-induced tumors in horses and other equids, discuss possible routes of PV transmission in equid species, and present recent developments aiming at introducing the PV VLP-based vaccine technology into equine medicine.

Bovine Papillomavirus Type 1 or 2 Virion-Infected Primary Fibroblasts Constitute a Near-Natural Equine Sarcoid Model.

Equine sarcoids are common, locally aggressive skin tumors induced by bovine papillomavirus types 1, 2, and possibly 13 (BPV1, BPV2, BPV13). Current in vitro models do not mimic de novo infection. We established primary fibroblasts from horse skin and succeeded in infecting these cells with native BPV1 and BPV2 virions. Subsequent cell characterization was carried out by cell culture, immunological, and molecular biological techniques. Infection of fibroblasts with serial 10-fold virion dilutions (2 × 106-20 virions) uniformly led to DNA loads settling at around 150 copies/cell after four passages. Infected cells displayed typical features of equine sarcoid cells, including hyperproliferation, and loss of contact inhibition. Neither multiple passaging nor storage negatively affected cell hyperproliferation, viral DNA replication, and gene transcription, suggestive for infection-mediated cell immortalization. Intriguingly, extracellular vesicles released by BPV1-infected fibroblasts contained viral DNA that was most abundant in the fractions enriched for apoptotic bodies and exosomes. This viral DNA is likely taken up by non-infected fibroblasts. We conclude that equine primary fibroblasts stably infected with BPV1 and BPV2 virions constitute a valuable near-natural model for the study of yet unexplored mechanisms underlying the pathobiology of BPV1/2-induced sarcoids.

Loneliness and self-harm in adolescents during the first national COVID-19 lockdown: results from a survey of 10,000 secondary school pupils in England.

Adolescents' loneliness and self-harm have received considerable attention during the COVID-19 pandemic with concerns that the socioecological changes taking place would contribute to an escalation of both loneliness and self-harm. However, empirical evidence is scant. We estimated the prevalence of loneliness and self-harm in adolescent school pupils and investigated the association of loneliness and change in loneliness during the UK's first lockdown with self-harm during lockdown in a cross-sectional school survey (OxWell) involving 10,460 12-18-year-olds from south England. Loneliness was measured with four items. Self-harm was ascertained through a detailed questionnaire. The prevalence of loneliness and self-harm were estimated applying post-stratification weights to account for differences between the study sample and the target population. The associations between indicators of loneliness and self-harm were examined using mixed effect models. 1,896 of 10,460 adolescents (18.1%) reported feeling lonely 'often' (weighted proportion 16.8%). 3,802/10,460 (36.4%; weighted proportion 35%) felt more lonely since lockdown. Self-harm during lockdown was reported by 787/10,460 adolescents (7.5%; weighted proportion 6.7%). Controlling for confounders, adolescents who reported feeling lonely 'often' [adjusted odds ratio (aOR) 2.8, 95% CI 2.1-3.9, p < 0.0001] or 'sometimes' (aOR 2.2, 95% CI 1.5-3.2, p < 0.0001) were more likely to self-harm during lockdown relative to adolescents who reported 'never' or 'hardly ever' feeling lonely. Exacerbation in loneliness during lockdown was associated with an increase in the odds of self-harm during lockdown. Loneliness, heightened loneliness and self-harm were common during lockdown and closely linked. It is important to support schools in address loneliness and self-harm as part of efforts to improve well-being as the long tail of the pandemic continues to impact on child and adolescent mental health. Understanding how loneliness and self-harm may co-vary could be important for future self-harm reduction strategies in young persons. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-022-03651-5.

Tumor Cell Plasticity in Equine Papillomavirus-Positive Versus-Negative Squamous Cell Carcinoma of the Head and Neck.

Squamous cell carcinoma of the head and neck (HNSCC) is a common malignant tumor in humans and animals. In humans, papillomavirus (PV)-induced HNSCCs have a better prognosis than papillomavirus-unrelated HNSCCs. The ability of tumor cells to switch from epithelial to mesenchymal, endothelial, or therapy-resistant stem-cell-like phenotypes promotes disease progression and metastasis. In equine HNSCC, PV-association and tumor cell phenotype switching are poorly understood. We screened 49 equine HNSCCs for equine PV (EcPV) type 2, 3 and 5 infection. Subsequently, PV-positive versus -negative lesions were analyzed for expression of selected epithelial (keratins, ß-catenin), mesenchymal (vimentin), endothelial (COX-2), and stem-cell markers (CD271, CD44) by immunohistochemistry (IHC) and immunofluorescence (IF; keratins/vimentin, CD44/CD271 double-staining) to address tumor cell plasticity in relation to PV infection. Only EcPV2 PCR scored positive for 11/49 equine HNSCCs. IHC and IF from 11 EcPV2-positive and 11 EcPV2-negative tumors revealed epithelial-to-mesenchymal transition events, with vimentin-positive cells ranging between <10 and >50%. CD44- and CD271-staining disclosed the intralesional presence of infiltrative tumor cell fronts and double-positive tumor cell subsets independently of the PV infection status. Our findings are indicative of (partial) epithelial-mesenchymal transition events giving rise to hybrid epithelial/mesenchymal and stem-cell-like tumor cell phenotypes in equine HNSCCs and suggest CD44 and CD271 as potential malignancy markers that merit to be further explored in the horse.

Depression and memory function - evidence from cross-lagged panel models with unit fixed effects in ELSA and HRS.

BACKGROUND: Individuals with depression are often found to perform worse on cognitive tests and to have an increased risk of dementia. The causes and the direction of these associations are however not well understood. We looked at two specific hypotheses, the aetiological risk factor hypothesis and the reverse causality hypothesis. METHOD: We analysed observational data from two cohorts, English Longitudinal Study of Ageing (ELSA) and Health and Retirement Study (HRS), using cross-lagged panel models with unit fixed effects. Each model was run once with depression and repeated with cognition as the dependent variable and the other variable as the main explanatory variable. All models were estimated separately for contemporaneous effects and lagged effects up to 8 years in the past. We contrasted the results with models making the random effects assumption. RESULTS: Evidence from the fixed effects models is mixed. We find no evidence for the reverse causality hypothesis in ELSA and HRS. While there is no evidence for the aetiological risk factors hypothesis in ELSA, results from HRS indicate some effects. CONCLUSION: Our findings suggest that current levels of cognitive function do not influence future levels of depression. Results in HRS provide some evidence that current levels of depressive symptoms influence future cognition.

Influenza virus vector iNS1 expressing bovine papillomavirus 1 (BPV1) antigens efficiently induces tumour regression in equine sarcoid patients.

Bovine papillomaviruses types 1 and 2 (BPV1, BPV2) commonly induce skin tumours termed sarcoids in horses and other equids. Sarcoids seriously compromise the health and welfare of affected individuals due to their propensity to resist treatment and reoccur in a more severe form. We have developed influenza (Flu) A and B virus vectors that harbour a truncated NS1 gene (iNS) assuring interferon induction and co-express shuffled BPV1 E6 and E7 antigens for sarcoid immunotherapy. In a safety trial involving 12 healthy horses, intradermal administration of iNSA/E6E7equ and iNSB/E6E7equ was well tolerated, with the only transient side effect being mild fever in four horses. Repeated screening of secretions and faeces by RT-PCR and plaque assay revealed no virus shedding, thus also confirming biological safety. In a patient trial involving 29 horses bearing BPV1-induced single or multiple sarcoids, at least one lesion per horse was intratumourally injected and then boosted with iNSA/E6E7equ and/or iNSB/E6E7equ. The treatment induced a systemic antitumour response as reflected by the synchronous regression of injected and non-injected lesions. Irrespective of vaccination schemes, complete tumour regression was achieved in 10/29 horses. In 10/29 horses, regression is still ongoing (May 2021). Intriguingly, scrapings collected from former tumour sites in two patients tested negative by BPV1 PCR. Nine severely affected individuals with a history of unsuccessful therapeutic attempts did not (6/29) or only transiently (3/29) respond to the treatment. INSA/E6E7equ and iNSB/E6E7equ proved safe and effective in significantly reducing the tumour burden even in severe cases.

COVID-19 partial school closures and mental health problems: A cross-sectional survey of 11,000 adolescents to determine those most at risk.

BACKGROUND: Understanding adolescents' mental health during lockdown and identifying those most at risk is an urgent public health challenge. This study surveyed school pupils across Southern England during the first COVID-19 school lockdown to investigate situational factors associated with mental health difficulties and how they relate to pupils' access to in-school educational provision. METHODS: A total of 11,765 pupils in years 8-13 completed a survey in June-July 2020, including questions on mental health, risk indicators and access to school provision. Pupils at home were compared to those accessing in-school provision on risk and contextual factors and mental health outcomes. Multilevel logistic regression analyses compared the effect of eight risk and contextual factors, including access to in-school provision, on depression, anxiety and self-reported deterioration in mental wellbeing. RESULTS: Females, pupils who had experienced food poverty and those who had previously accessed mental health support were at greatest risk of depression, anxiety and a deterioration in wellbeing. Pupils whose parents were going out to work and those preparing for national examinations in the subsequent school year were also at increased risk. Pupils accessing in-school provision had poorer mental health, but this was accounted for by the background risk and contextual factors assessed, in line with the allocation of in-school places to more vulnerable pupils. CONCLUSIONS: Although the strongest associations with poor mental health during school closures were established risk factors, further contextual factors of particular relevance during lockdown had negative impacts on wellbeing. Identifying those pupils at greatest risk for poor outcomes is critical for ensuring that appropriate educational and social support can be given to pupils either at home or in-school during subsequent lockdowns.

Screening for bovine papillomavirus type 13 (BPV13) in a European population of sarcoid-bearing equids.

BACKGROUND: Bovine papillomavirus types 1 and 2 (BPV1 and BPV2) are accepted aetiological agents of equine sarcoids. Recently, genetically similar BPV13 has been identified from equine sarcoids in Brazil. OBJECTIVES: To determine whether BPV13 DNA can be also found in sarcoid-affected horses in Austria, and donkeys in Northern Italy and the UK, and should hence be considered in the context of vaccine-mediated sarcoid prevention. STUDY DESIGN: Cross sectional study. METHODS: A total of 194 archival, equine and asinine DNA isolates derived from confirmedly delta-BPV-positive tumours were subjected to quality control by photometric analysis and equine beta-actin PCR. Isolates with DNA concentrations >0.9 ng/µl and confirmed PCR-compatibility (n = 135) were subsequently screened for the presence of BPV13 DNA using BPV13-specific PCR primers for amplification of a 771 bp region comprising the BPV13 E5 gene. RESULTS: BPV13 E5 PCR scored negative for all 135 samples. Included positive, negative and no-template controls yielded anticipated results, thus confirming reliability of obtained data. MAIN LIMITATIONS: Moderate number of tested tumour DNA extracts (n = 135; equivalent to 127 tumour-affected equids). CONCLUSIONS: Despite its moderate size, the sample was considered representative enough to suggest a low occurrence of BPV13 in Austria, as it randomly comprised equine patients of different breed, age, gender, and European provenience. BPV13 was not associated with tested sarcoids in rescued donkeys originating from several other European countries. Large-scale BPV13 screenings are necessary to allow for a more precise estimation of the prevalence and distribution of BPV13 infections in European equids suffering from sarcoid disease.

The Dementias Platform UK (DPUK) Data Portal.

The Dementias Platform UK Data Portal is a data repository facilitating access to data for 3 370 929 individuals in 42 cohorts. The Data Portal is an end-to-end data management solution providing a secure, fully auditable, remote access environment for the analysis of cohort data. All projects utilising the data are by default collaborations with the cohort research teams generating the data. The Data Portal uses UK Secure eResearch Platform infrastructure to provide three core utilities: data discovery, access, and analysis. These are delivered using a 7 layered architecture comprising: data ingestion, data curation, platform interoperability, data discovery, access brokerage, data analysis and knowledge preservation. Automated, streamlined, and standardised procedures reduce the administrative burden for all stakeholders, particularly for requests involving multiple independent datasets, where a single request may be forwarded to multiple data controllers. Researchers are provided with their own secure 'lab' using VMware which is accessed using two factor authentication. Over the last 2 years, 160 project proposals involving 579 individual cohort data access requests were received. These were received from 268 applicants spanning 72 institutions (56 academic, 13 commercial, 3 government) in 16 countries with 84 requests involving multiple cohorts. Projects are varied including multi-modal, machine learning, and Mendelian randomisation analyses. Data access is usually free at point of use although a small number of cohorts require a data access fee.

Real-world evidence in Alzheimer's disease: The ROADMAP Data Cube.

INTRODUCTION: The ROADMAP project aimed to provide an integrated overview of European real-world data on Alzheimer's disease (AD) across the disease spectrum. METHODS: Metadata were identified from data sources in catalogs of European AD projects. Priority outcomes for different stakeholders were identified through systematic literature review, patient and public consultations, and stakeholder surveys. RESULTS: Information about 66 data sources and 13 outcome domains were integrated into a Data Cube. Gap analysis identified cognitive ability, functional ability/independence, behavioral/neuropsychiatric symptoms, treatment, comorbidities, and mortality as the outcomes collected most. Data were most lacking in caregiver-related outcomes. In general, electronic health records covered a broader, less detailed data spectrum than research cohorts. DISCUSSION: This integrated real-world AD data overview provides an intuitive visual model that facilitates initial assessment and identification of gaps in relevant outcomes data to inform future prospective data collection and matching of data sources and outcomes against research protocols.

What outcomes are important to patients with mild cognitive impairment or Alzheimer's disease, their caregivers, and health-care professionals? A systematic review.

INTRODUCTION: Clinical trials involving patients with Alzheimer's disease (AD) continue to try to identify disease-modifying treatments. Although trials are designed to meet regulatory and registration requirements, many do not measure outcomes of the disease most relevant to key stakeholders. METHODS: A systematic review sought research that elicited information from people with AD, their caregivers, and health-care professionals on which outcomes of the disease were important. Studies published in any language between 2008 and 2017 were included. RESULTS: Participants in 34 studies described 32 outcomes of AD. These included clinical (memory, mental health), practical (ability to undertake activities of daily living, access to health information), and personal (desire for patient autonomy, maintenance of identity) outcomes of the disease. DISCUSSION: Evidence elicited directly from the people most affected by AD reveals a range of disease outcomes that are relevant to them but are not commonly captured in clinical trials of new treatments.

Potential of a BPV1 L1 VLP vaccine to prevent BPV1- or BPV2-induced pseudo-sarcoid formation and safety and immunogenicity of EcPV2 L1 VLPs in horse.

We have previously shown that immunization of horses with bovine papillomavirus type 1 (BPV1) L1 virus-like particles (VLPs) is safe and highly immunogenic and that BPV1 and bovine papillomavirus type 2 (BPV2) are closely related serotypes. Here we evaluated the protective potential of a BPV1 L1 VLP vaccine against experimental BPV1 and BPV2 challenge and studied the safety and immunogenicity of a bivalent equine papillomavirus type 2 (EcPV2)/BPV1 L1 VLP vaccine. Fourteen healthy horses were immunized with BPV1 L1 VLPs (100 µg per injection) plus adjuvant on days 0 and 28, while seven remained unvaccinated. On day 42, all 21 horses were challenged intradermally at 10 sites of the neck with 107 BPV1 virions per injection. In analogy, 14 horses immunized twice with EcPV2 plus BPV1 L1 VLPs (50 µg each) and seven control animals were challenged with 107 BPV2 virions per injection. Immunization with BPV1 L1 VLPs alone induced a robust antibody response (day 42 median titre: 12 800), and BPV1-inoculated skin remained unchanged in 13/14 vaccinated horses. Immunization with the bivalent vaccine was safe, resulted in lower median day 42 antibody titres of 400 for BPV1 and 1600 for EcPV2 and conferred significant yet incomplete cross-protection from BPV2-induced tumour formation, with 11/14 horses developing small, short-lived papules. Control horses developed pseudo-sarcoids at all inoculation sites. The monovalent BPV1 L1 VLP vaccine proved highly effective in protecting horses from BPV1-induced pseudo-sarcoid formation. Incomplete protection from BPV2-induced tumour development conferred by the bivalent vaccine is due to the poorer immune response by immune interference or lower cross-neutralization titres to heterologous BPV2 virions.

Chimeric L2-Based Virus-Like Particle (VLP) Vaccines Targeting Cutaneous Human Papillomaviruses (HPV).

Common cutaneous human papillomavirus (HPV) types induce skin warts, whereas species beta HPV are implicated, together with UV-radiation, in the development of non-melanoma skin cancer (NMSC) in immunosuppressed patients. Licensed HPV vaccines contain virus-like particles (VLP) self-assembled from L1 major capsid proteins that provide type-restricted protection against mucosal HPV infections causing cervical and other ano-genital and oro-pharyngeal carcinomas and warts (condylomas), but do not target heterologous HPV. Experimental papillomavirus vaccines have been designed based on L2 minor capsid proteins that contain type-common neutralization epitopes, to broaden protection to heterologous mucosal and cutaneous HPV types. Repetitive display of the HPV16 L2 cross-neutralization epitope RG1 (amino acids (aa) 17-36) on the surface of HPV16 L1 VLP has greatly enhanced immunogenicity of the L2 peptide. To more directly target cutaneous HPV, L1 fusion proteins were designed that incorporate the RG1 homolog of beta HPV17, the beta HPV5 L2 peptide aa53-72, or the common cutaneous HPV4 RG1 homolog, inserted into DE surface loops of HPV1, 5, 16 or 18 L1 VLP scaffolds. Baculovirus expressed chimeric proteins self-assembled into VLP and VLP-raised NZW rabbit immune sera were evaluated by ELISA and L1- and L2-based pseudovirion (PsV) neutralizing assays, including 12 novel beta PsV types. Chimeric VLP displaying the HPV17 RG1 epitope, but not the HPV5L2 aa53-72 epitope, induced cross-neutralizing humoral immune responses to beta HPV. In vivo cross-protection was evaluated by passive serum transfer in a murine PsV challenge model. Immune sera to HPV16L1-17RG1 VLP (cross-) protected against beta HPV5/20/24/38/96/16 (but not type 76), while antisera to HPV5L1-17RG1 VLP cross-protected against HPV20/24/96 only, and sera to HPV1L1-4RG1 VLP cross-protected against HPV4 challenge. In conclusion, RG1-based VLP are promising next generation vaccine candidates to target cutaneous HPV infections.

Attenuated Recombinant Influenza A Virus Expressing HPV16 E6 and E7 as a Novel Therapeutic Vaccine Approach.

Persistent infection with high-risk human papillomavirus (HPV) types, most often HPV16 and HPV18, causes all cervical and most anal cancers, and a subset of vulvar, vaginal, penile and oropharyngeal carcinomas. Two prophylactic virus-like particle (VLPs)-based vaccines, are available that protect against vaccine type-associated persistent infection and associated disease, yet have no therapeutic effect on existing lesions or infections. We have generated recombinant live-attenuated influenza A viruses expressing the HPV16 oncogenes E6 and E7 as experimental immunotherapeutic vaccine candidates. The influenza A virus life cycle lacks DNA intermediates as important safety feature. Different serotypes were generated to ensure efficient prime and boost immunizations. The immune response to vaccination in C57BL/6 mice was characterized by peptide ELISA and IFN-γ ELISpot, demonstrating induction of cell-mediated immunity to HPV16 E6 and E7 oncoproteins. Prophylactic and therapeutic vaccine efficacy was analyzed in the murine HPV16-positive TC-1 tumor challenge model. Subcutaneous (s.c.) prime and boost vaccinations of mice with recombinant influenza A serotypes H1N1 and H3N2, followed by challenge with TC-1 cells resulted in complete protection or significantly reduced tumor growth as compared to control animals. In a therapeutic setting, s.c. vaccination of mice with established TC-1 tumors decelerated tumor growth and significantly prolonged survival. Importantly, intralesional vaccine administration induced complete tumor regression in 25% of animals, and significantly reduced tumor growth in 50% of mice. These results suggest recombinant E6E7 influenza viruses as a promising new approach for the development of a therapeutic vaccine against HPV-induced disease.

A chimeric 18L1-45RG1 virus-like particle vaccine cross-protects against oncogenic alpha-7 human papillomavirus types.

Persistent infection with oncogenic human papillomaviruses (HPV) types causes all cervical and a subset of other anogenital and oropharyngeal carcinomas. Four high-risk (hr) mucosal types HPV16, 18, 45, or 59 cause almost all cervical adenocarcinomas (AC), a subset of cervical cancer (CxC). Although the incidence of cervical squamous cell carcinoma (SCC) has dramatically decreased following introduction of Papanicolaou (PAP) screening, the proportion of AC has relatively increased. Cervical SCC arise mainly from the ectocervix, whereas AC originate primarily from the endocervical canal, which is less accessible to obtain viable PAP smears. Licensed (bivalent and quadrivalent) HPV vaccines comprise virus-like particles (VLP) of the most important hr HPV16 and 18, self-assembled from the major capsid protein L1. Due to mainly type-restricted efficacy, both vaccines do not target 13 additional hr mucosal types causing 30% of CxC. The papillomavirus genus alpha species 7 (α7) includes a group of hr types of which HPV18, 45, 59 are proportionally overrepresented in cervical AC and only partially (HPV18) targeted by current vaccines. To target these types, we generated a chimeric vaccine antigen that consists of a cross-neutralizing epitope (homologue of HPV16 RG1) of the L2 minor capsid protein of HPV45 genetically inserted into a surface loop of HPV18 L1 VLP (18L1-45RG1). Vaccination of NZW rabbits with 18L1-45RG1 VLP plus alum-MPL adjuvant induced high-titer neutralizing antibodies against homologous HPV18, that cross-neutralized non-cognate hr α7 types HPV39, 45, 68, but not HPV59, and low risk HPV70 in vitro, and induced a robust L1-specific cellular immune response. Passive immunization protected mice against experimental vaginal challenge with pseudovirions of HPV18, 39, 45 and 68, but not HPV59 or the distantly related α9 type HPV16. 18L1-45RG1 VLP might be combined with our previously described 16L1-16RG1 VLP to develop a second generation bivalent vaccine with extended spectrum against hr HPV.