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The work outlined herein describes AU-011, a novel recombinant papillomavirus-like particle (VLP) drug conjugate and its initial evaluation as a potential treatment for primary uveal melanoma. The VLP is conjugated with a phthalocyanine photosensitizer, IRDye 700DX, that exerts its cytotoxic effect through photoactivation with a near-infrared laser. We assessed the anticancer properties of AU-011 in vitro utilizing a panel of human cancer cell lines and in vivo using murine subcutaneous and rabbit orthotopic xenograft models of uveal melanoma. The specificity of VLP binding (tumor targeting), mediated through cell surface heparan sulfate proteoglycans (HSPG), was assessed using HSPG-deficient cells and by inclusion of heparin in in vitro studies. Our results provide evidence of potent and selective anticancer activity, both in vitro and in vivo. AU-011 activity was blocked by inhibiting its association with HSPG using heparin and using cells lacking surface HSPG, indicating that the tumor tropism of the VLP was not affected by dye conjugation and cell association is critical for AU-011–mediated cytotoxicity. Using the uveal melanoma xenograft models, we observed tumor uptake following intravenous (murine) and intravitreal (rabbit) administration and, after photoactivation, potent dose-dependent tumor responses. Furthermore, in the rabbit orthotopic model, which closely models uveal melanoma as it presents in the clinic, tumor treatment spared the retina and adjacent ocular structures. Our results support further clinical development of this novel therapeutic modality that might transform visual outcomes and provide a targeted therapy for the early-stage treatment of patients with this rare and life-threatening disease. Mol Cancer Ther; 17(2); 565–74. ©2017 AACR.

Recent advances in immunotherapy against cancer underscore the importance of T lymphocytes and tumor microenvironment, but few vaccines targeting cancer have been approved likely due in part to the dearth of common tumor antigens, insufficient immunogenicity and the evolution of immune evasion mechanisms during the progression to malignancy. Human papillomaviruses (HPVs) are the primary etiologic agents of cervical cancer and progression from persistent HPV-infection to cervical intraepithelial lesions and eventually cancer requires persistent expression of the oncoproteins E6 and E7. This offers the opportunity to specifically target these virus-specific antigens for vaccine-induced clearance of infected cells before cancers develop. Here we have evaluated the immunogenicity of Adenovirus Types 26 and 35 derived vectors expressing a fusion of HPV16 E6 and E7 oncoproteins after intramuscular (IM) and/or intravaginal (Ivag) immunization in mice. The adenovirus vectors were shown to transduce an intact cervicovaginal epithelium. IM prime followed by Ivag boost maximized the induction and trafficking of HPV-specific CD8+ T cells producing IFN-γ and TNF-α to the cervicovaginal tract. Importantly, the cervicovaginal CD8+ T cells expressed CD69 and CD103; hallmarks of intraepithelial tissue-resident memory CD8+ T cells. This prime-boost strategy targeting heterologous locations also induced circulating HPV-specific CD8+ T cell responses. Our study prompts further evaluation of Ivag immunization with adenoviral vectors expressing modified E6 and E7 antigens for therapeutic vaccination against persistent HPV infection and cervical intraepithelial neoplasia.

Human papillomaviruses (HPVs) cause approximately 5% of cancer cases worldwide. Fortunately, three prophylactic vaccines have been approved to protect against HPV infections. Gardasil-9, the most recent HPV vaccine, is predicted to offer protection against the HPV types that cause ∼90% of cervical cancer, 86% of HPV-associated penile cancers, and ∼93% of HPV-associated head & neck cancers. As an alternative to Gardasil-9, we developed and tested a novel candidate vaccine targeting conserved epitopes in the HPV minor capsid protein, L2. We displayed a tandem HPV31/16L2 peptide (amino acid 17–31) or consensus peptides from HPV L2 (amino acid 69–86 or 108–122) on the surface of bacteriophage MS2 virus-like particles (VLPs). Mice immunized with the MS2 VLPs displaying the tandem peptide or immunized with a mixture of VLPs (displaying the tandem peptide and consensus peptide 69–86) elicited high titer antibodies against individual L2 epitopes. Moreover, vaccinated mice were protected from cervicovaginal infection with HPV pseudoviruses 16, 31, 45, 58 and sera from immunized mice neutralized HPV pseudoviruses 18 and 33 at levels similar to mice immunized with Gardasil-9. These results suggest that immunization with a tandem, L2 peptide or a low valency mixture of L2 peptide-displaying VLPs can provide broad protection against multiple HPV types.

Author(s): Safaeian, Mahboobeh; Sampson, Joshua N; Pan, Yuanji; Porras, Carolina; Kemp, Troy J; Herrero, Rolando; Quint, Wim; van Doorn, Leen Jan; Schussler, John; Lowy, Douglas R; Schiller, John; Schiffman, Mark T; Rodriguez, Ana Cecilia; Gail, Mitchell H; Hildesheim, Allan; Gonzalez, Paula; Pinto, Ligia A; Kreimer, Aimee R; Costa Rica HPV Vaccine Trial (CVT) Group | Abstract: BackgroundPreviously, we demonstrated similar human papillomavirus (HPV)16/18 vaccine efficacy estimates and stable HPV16/18 antibody levels four years postvaccination in a nonrandomized analysis of women who received a varying number of doses of the bivalent HPV16/18 vaccine. Here we extend data to seven years following initial vaccination.MethodsWe evaluated HPV16/18-vaccinated women who received one (n = 134), two (n 0/1 = 193, n 0/6 = 79), or three doses (n = 2043) to a median of 6.9 years postvaccination. Cervical HPV DNA was measured with the SPF10- DEIA-LiPA PCR system; HPV16/18-specific antibody levels were measured using enzyme-linked immunosorbent assays (n = 486). Infection and immunological measures were compared across vaccine dose groups. Prevalent HPV infection at year 7 was also compared with an unvaccinated control group (UCG). All statistical tests were two-sided.ResultsAmong women in the three-dose, two-dose 0/6 , two-dose 0/1 , and one-dose groups, cumulative incident HPV16/18 infection rates (No. of events/No. of individuals) were 4.3% (88/2036, 95% confidence interval [CI] = 3.5% to 5.3%), 3.8% (3/78, 95% CI = 1.0% to 10.1%), 3.6% (7/192, 95% CI = 1.6% to 7.1%), and 1.5% (2/133, 95% CI = 0.3% to 4.9%; P = 1.00, .85, .17 comparing the two-dose 0/6 , two-dose 0/1 , and one-dose groups to the three-dose group, respectively). The prevalence of other carcinogenic and noncarcinogenic HPV types, excluding HPV16/18/31/33/45, were high and not statistically different among all dose groups, indicating that the low incidence of HPV16/18 in the one- and two-dose groups was not due to lack of exposure. At seven years, 100% of participants in all dose groups remained HPV16 and HPV18 seropositive. A non-statistically significant decrease in the geometric mean of the HPV16 antibody levels between years 4 and 7 was observed among women in the three-dose group: -10.8% (95% CI = -25.3% to 6.6%); two-dose (0/6 months) group: -17.3% (95% CI = -39.3% to 12.8%), two-dose (0/1 month) group: -6.9% (95% CI = -22.1% to 11.2%), and one-dose group: -5.5% (95% CI = -29.7% to 27.0%); results were similar for HPV18.ConclusionsAt an average of seven years of follow-up, we observed similar low rates of HPV16/18 infections and slight, if any, decreases in HPV16/18 antibody levels by dose group.

Papillomavirus capsids can package a wide variety of nonviral DNA plasmids and deliver the packaged genetic material to cells, making them attractive candidates for targeted gene delivery vehicles. However, the papillomavirus vectors generated by current methods are unlikely to be suitable for clinical applications. We have developed a chemically defined, cell-free, papillomavirus-based vector production system that allows the incorporation of purified plasmid DNA (pseudogenome) into high-titer papillomavirus L1/L2 capsids. We investigated the incorporation of several DNA forms into a variety of different papillomavirus types, including human and animal types. Our results show that papillomavirus capsids can package and transduce linear or circular DNA under defined conditions. Packaging and transduction efficiencies were surprisingly variable across capsid types, DNA forms, and assembly reaction conditions. The pseudoviruses produced by these methods are sensitive to the same entry inhibitors as cell-derived pseudovirions, including neutralizing antibodies and heparin. The papillomavirus vector production systems developed in this study generated as high as 1011 infectious units/mg of L1. The pseudoviruses were infectious both in vitro and in vivo and should be compatible with good manufacturing practice (GMP) requirements.

Human papillomavirus (HPV) causes greater than 5% of cancers worldwide, including all cervical cancers and an alarmingly increasing proportion of oropharyngeal cancers (OPCs). Despite markedly reduced cervical cancer incidence in industrialized nations with organized screening programs, cervical cancer remains the second most common cause of death from cancer in women worldwide, as developing countries lack resources for universal, high-quality screening. In the United States, HPV-related OPC is only 1 of 5 cancers with a rising incidence since 1975 and now has taken over the cervix as the most common site of HPV-related cancer. Similar trends follow throughout North America and Europe. The need for early detection and prevention is paramount. Despite the common etiologic role of HPV in the development of cervical cancer and HPV-associated OPC, great disparity exists between incidence, screening modalities (or lack thereof), treatment, and prevention in these 2 very distinct cohorts. These differences in cervical cancer and HPV-associated OPC and their impact are discussed here. Cancer 2017;123:2219-2229. © 2017 American Cancer Society.

This study examined the ability of a papillomavirus-like particle drug conjugate, belzupacap sarotalocan (AU-011), to eradicate subcutaneous tumors after intravenous injection and to subsequently elicit long-term antitumor immunity in the TC-1 syngeneic murine tumor model. Upon in vitro activation with near-infrared light (NIR), AU-011–mediated cell killing was proimmunogenic in nature, resulting in the release of damage-associated molecular patterns such as DNA, ATP, and HMGB-1, activation of caspase-1, and surface relocalization of calreticulin and HSP70 on killed tumor cells. A single in vivo administration of AU-011 followed by NIR caused rapid cell death, leading to long-term tumor regression in ∼50% of all animals. Within hours of treatment, calreticulin surface expression, caspase-1 activation, and depletion of immunosuppressive leukocytes were observed in tumors. Combination of AU-011 with immune-checkpoint inhibitor antibodies, anti–CTLA-4 or anti–PD-1, improved therapeutic efficacy, resulting in 70% to 100% complete response rate that was durable 100 days after treatment, with 50% to 80% of those animals displaying protection from secondary tumor rechallenge. Depletion of CD4+ or CD8+ T cells, either at the time of AU-011 treatment or secondary tumor rechallenge of tumor-free mice, indicated that both cell populations are vital to AU-011′s ability to eradicate primary tumors and induce long-lasting antitumor protection. Tumor-specific CD8+ T-cell responses could be observed in circulating peripheral blood mononuclear cells within 3 weeks of AU-011 treatment. These data, taken together, support the conclusion that AU-011 has a direct cytotoxic effect on tumor cells and induces long-term antitumor immunity, and this activity is enhanced when combined with checkpoint inhibitor antibodies.

Background The Costa Rica HPV Vaccine Trial has documented cross-protection of the bivalent HPV vaccine against HPV31/33/45 up to 7 years after vaccination, even with one dose of the vaccine. However, the durability of such protection remains unknown. Here, we evaluate the efficacy of different schedules of the vaccine against HPV31/33/45 out to 11 years postvaccination, expanding to other nontargeted HPV types. Methods We compared the rates of HPV infection in vaccinated women with the rates in a comparable cohort of unvaccinated women. We estimated the average vaccine efficacy (VEavg) against incident infections and tested for a change in VE over time. Results Among 3-dose women, we observed statistically significant cross-protection against HPV31/33/45 (VEavg = 64.4%, 95% confidence interval [CI] = 57.7% to 70.0%). Additionally, we observed borderline, statistically significant cross-protection against HPV35 (VEavg = 23.2%, 95% CI = 0.3% to 40.8%) and HPV58 (VEavg = 21.2%, 95% CI = 4.2% to 35.3%). There was no decrease in VE over time (two-sided Ptrend > .05 for HPV31, -33, -35, -45, and -58). As a benchmark, VEavg against HPV16/18 was 82.0% (95% CI = 77.3% to 85.7%). Among 1-dose women, we observed comparable efficacy against HPV31/33/45 (VEavg = 54.4%, 95% CI = 21.0% to 73.7%). Acquisition of nonprotected HPV types was similar between vaccinated and unvaccinated women, indicating that the difference in HPV infection rates was not attributable to differential genital HPV exposure. Conclusions Substantial cross-protection afforded by the bivalent vaccine against HPV31/33/45, and to a lesser extent, HPV35 and HPV58, was sustained and remained stable after 11 years postvaccination, reinforcing the notion that the bivalent vaccine is an effective option for protection against HPV-associated cancers.

Infectious human papillomavirus 16 (HPV16) L1/L2 pseudovirions were found to remain largely intact during vesicular transport to the nucleus. By electron microscopy, capsids with a diameter of 50 nm were clearly visible within small vesicles attached to mitotic chromosomes and to a lesser extent within interphase nuclei, implying nuclear disassembly. By confocal analysis, it was determined that nuclear entry of assembled L1 is dependent upon the presence of the minor capsid protein, L2, but independent of encapsidated DNA. We also demonstrate that L1 nuclear localization and mitotic chromosome association can occur in vivo in the murine cervicovaginal challenge model of HPV16 infection. These findings challenge the prevailing concepts of PV uncoating and disassembly. More generally, they document that a largely intact viral capsid can enter the nucleus within a transport vesicle, establishing a novel mechanism by which a virus accesses the nuclear cellular machinery. IMPORTANCE Papillomaviruses (PVs) comprise a large family of nonenveloped DNA viruses that include HPV16, among other oncogenic types, the causative agents of cervical cancer. Delivery of the viral DNA into the host cell nucleus is necessary for establishment of infection. This was thought to occur via a subviral complex following uncoating of the larger viral capsid. In this study, we demonstrate that little disassembly of the PV capsid occurs prior to nuclear delivery. These surprising data reveal a previously unrecognized viral strategy to access the nuclear replication machinery. Understanding viral entry mechanisms not only increases our appreciation of basic cell biological pathways but also may lead to more effective antiviral interventions.

Background The AS04-adjuvanted HPV16/18 (AS04-HPV16/18) vaccine provides excellent protection against targeted human papillomavirus (HPV) types and a variable degree of cross-protection against others, including types 6/11/31/33/45. High efficacy against any cervical intraepithelial neoplasia grade 3 or greater (CIN3+; >90%) suggests that lower levels of protection may exist for a wide range of oncogenic HPV types, which is difficult to quantify in individual trials. Pooling individual-level data from two randomized controlled trials, we aimed to evaluate AS04-HPV16/18 vaccine efficacy against incident HPV infections and cervical abnormalities . Methods Data were available from the Costa Rica Vaccine Trial (NCT00128661) and Papilloma Trial Against Cancer in Young Adults trial (NCT00122681), two large-scale, double-blind randomized controlled trials of the AS04-HPV16/18 vaccine. Primary analyses focused on disease-free women with no detectable cervicovaginal HPV at baseline. Results A total of 12 550 women were included in our primary analyses (HPV arm = 6271, control arm = 6279). Incidence of 6-month persistent oncogenic and nononcogenic infections, excluding known and accepted protected types 6/11/16/18/31/33/45 (focusing on 34/35/39/40/42/43/44/51/52/53/54/56/58/59/66/68/73/70/74), was statistically significantly lower in the HPV arm than in the control arm (efficacy = 9.9%, 95% confidence interval [CI] = 1.7% to 17.4%). Statistically significant efficacy (P Conclusions The AS04-HPV16/18 vaccine provides some additional cross-protection beyond established protected types, which partially explains the high efficacy against CIN3+.

The objective of this analysis was to compare the anti-HPV GMTs and their distribution after a 6-month or a 3-8 -y interval between two HPV vaccine doses. The results from two clinical trials, conducted by the same team in the same region, with serological assays performed at the same laboratory using the same ELISA methodology were compared. In the first study, 173 9-10-y-old girls and boys received two doses of 9vHPV vaccine at a 6-month interval; in the second study, 31 girls vaccinated with one dose of 4vHPV at the age of 9-14 y received a dose of 9vHPV 3-8 y later (mean 5.4 y). In both studies, blood samples were collected before and 1 month post second dose. Despite large differences in the time since the first dose, all subjects (100%) were seropositive to the common 4 HPV types (6, 11, 16 and 18) to both vaccines, with comparable GMTs and titer distributions before the second dose. One month post second dose, the GMTs increased 40-91-fold for those with a 6-month interval between doses and 60-82-fold for those with a 3-8-y interval. Titer distributions after the booster dose were comparable in the two studies. These results indicate that 2-dose HPV vaccination schedules with an interval of several years could be used for pre-adolescents. Intervals longer than 6 months may facilitate logistics for immunization programs and could be useful during periods of vaccine shortage or as a transition while the effectiveness of a one-dose schedule is being evaluated.

Prevention is an essential component of cancer eradication. Next-generation sequencing of cancer genomes and epigenomes has defined large numbers of driver mutations and molecular subgroups, leading to therapeutic advances. By comparison, there is a relative paucity of such knowledge in premalignant neoplasia, which inherently limits the potential to develop precision prevention strategies. Studies on the interplay between germ-line and somatic events have elucidated genetic processes underlying premalignant progression and preventive targets. Emerging data hint at the immune system’s ability to intercept premalignancy and prevent cancer. Genetically engineered mouse models have identified mechanisms by which genetic drivers and other somatic alterations recruit inflammatory cells and induce changes in normal cells to create and interact with the premalignant tumor microenvironment to promote oncogenesis and immune evasion. These studies are currently limited to only a few lesion types and patients. In this Perspective, we advocate a large-scale collaborative effort to systematically map the biology of premalignancy and the surrounding cellular response. By bringing together scientists from diverse disciplines (e.g., biochemistry, omics, and computational biology; microbiology, immunology, and medical genetics; engineering, imaging, and synthetic chemistry; and implementation science), we can drive a concerted effort focused on cancer vaccines to reprogram the immune response to prevent, detect, and reject premalignancy. Lynch syndrome, clonal hematopoiesis, and cervical intraepithelial neoplasia which also serve as models for inherited syndromes, blood, and viral premalignancies, are ideal scenarios in which to launch this initiative.

Persistent human papillomavirus (HPV) is the primary etiologic agent of cervical cancer and causes a significant number of vulvar, penile, anal and oropharyngeal cancers. The development of highly effective HPV therapeutic vaccines is a reasonable goal given the recent advances in basic and applied immunology. A number of vaccine strategies designed to induce systemic T cell responses have been tested in clinical trials against high grade cervical or vulvar high grade neoplasia and cancers, but with limited success. In line with the emerging trend to focus more on the epithelial context of HPV infection and premalignant disease, it might be advantageous to develop vaccination strategies that promote trafficking of HPV-specific T cells into lesions and overcome the local immunosuppressive environment. The development of more biologically relevant animal models would improve the preclinical evaluation of therapeutic vaccine candidates. Finally, persistent infection and low grade lesions may prove to be easier targets for therapeutic vaccines, and these vaccines would likely be commercially viable in high income countries and valuable components in screen and treat programs in low resource settings.

The availability of high throughput DNA sequencing provides an opportunity to generate a potent immune stimulation against unique antigens expressed by tumors. Although such approaches have led to increased immune responses in certain individuals, it is often limited to a small patient population and is associated with high development and implementation costs. Therefore, there is an unmet need for an immunotherapy that is easy to manufacture at affordable cost and applicable across many different tumor types. Here, we propose a unique approach to leverage pre-existing anti-Human Cytomegalovirus (CMV) immunity using a defined cocktail of viral epitopes, to both directly kill the tumor cells and induce a secondary T cell response to tumor neoantigens. We chose to recruit CMV immunity because CMV infection is highly prevalent, reaching approximately 90% of the population by the age of 80 years, and because of the naturally-occurring inflation of anti-CMV T cell responses with age leads to high levels CMV-specific T cells. Consequently, in elderly individuals, CMV-specific T cells recognizing a limited number of viral epitopes constitute approximately 10% of all systemic CD4 and CD8 T cells, a level rarely achieved by conventional vaccination. Additionally, in contrast to other chronic viral infections, CMV-specific T cells remain highly functional. In our experimental model, mice persistently infected with Murine Cytomegalovirus (mCMV) were subcutaneously challenged with TC-1 tumor cells (expressing human papillomavirus E6 and E7 oncogenes) or colon adenocarcinoma MC38 tumor cells, followed by intratumoral injections of mCMV peptide antigens together with a Toll-like receptor 3 (TLR3) agonist poly(I:C). Intratumoral injection of mCMV MHC-I or MHC-II restricted epitopes alone led to local and systemic recall of mCMV-specific T cells, and a potent local immune activation resulting in complete rejection of TC-1 and MC38 tumors in a subset of animals. Coinjection of both MHC-I and MHC-II peptides resulted in complete tumor clearance is most animals. Clearance was associated with antigen spreading, as evidenced by protection from secondary tumor challenge and ex vivo IFN-gamma ELISPOT responses to tumor-specific epitopes. Our preclinical studies provide a proof of concept of a first-in-class tumor antigen-agnostic immunotherapy based on recruitment of pre-existing antiviral T cells. The approach induced rapid tumor regression, profound changes in the tumor immune environment, epitope spreading, and resulted in long-term tumor protection. We are currently investigating the contribution of other cell types including NK cells and B cells to the anti-tumor effect of our approach. Citation Format: Nicolas Cuburu, Lukas Bialkowski, Sergio M. Pontejo, Alexander Bell, Rina Kim, Cynthia D. Thompson, Douglas R. Lowy, John T. Schiller. Harnessing pre-existing viral immunity for development of a broadly applicable tumor immunotherapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5563.

Adenoviruses, papillomaviruses, and polyomaviruses are collectively known as small DNA tumor viruses. Although it has long been recognized that small DNA tumor virus oncoproteins and capsid proteins show a variety of structural and functional similarities, it is unclear whether these similarities reflect descent from a common ancestor, convergent evolution, horizontal gene transfer among virus lineages, or acquisition of genes from host cells. Here, we report the discovery of a dozen new members of an emerging virus family, the Adomaviridae, that unite a papillomavirus/polyomavirus-like replicase gene with an adenovirus-like virion maturational protease. Adomaviruses were initially discovered in a lethal disease outbreak among endangered Japanese eels. New adomavirus genomes were found in additional commercially important fish species, such as tilapia, as well as in reptiles. The search for adomavirus sequences also revealed an additional candidate virus family, which we refer to as xenomaviruses, in mollusk datasets. Analysis of native adomavirus virions and expression of recombinant proteins showed that the virion structural proteins of adomaviruses are homologous to those of both adenoviruses and another emerging animal virus family called adintoviruses. The results pave the way toward development of vaccines against adomaviruses and suggest a framework that ties small DNA tumor viruses into a shared evolutionary history.Author SummaryIn contrast to cellular organisms, viruses do not encode any universally conserved genes. Even within a given family of viruses, the amino acid sequences encoded by homologous genes can diverge to the point of unrecognizability. Although members of an emerging virus family, the Adomaviridae, encode replicative DNA helicase proteins that are recognizably similar to those of polyomaviruses and papillomaviruses, the functions of other adomavirus genes have been difficult to identify. Using a combination of laboratory and bioinformatic approaches, we identify the adomavirus virion structural proteins. The results link adomavirus virion protein operons to those of other midsize non-enveloped DNA viruses, including adenoviruses and adintoviruses.

We have established a cell-free in vitro system to study human papillomavirus type 16 (HPV16) assembly, a poorly understood process. L1/L2 capsomers, obtained from the disassembly of virus-like particles (VLPs), were incubated with nuclear extracts to provide access to the range of cellular proteins that would be available during assembly within the host cell. Incorporation of a reporter plasmid “pseudogenome” was dependent on the presence of both nuclear extract and ATP. Unexpectedly, L1/L2 VLPs that were not disassembled prior to incubation with a reassembly mixture containing nuclear extract also encapsidated a reporter plasmid. As with HPV pseudoviruses (PsV) generated intracellularly, infection by cell-free particles assembled in vitro required the presence of L2 and was susceptible to the same biochemical inhibitors, implying the cell-free assembled particles use the infectious pathway previously described for HPV16 produced in cell culture. Using biochemical and electron microscopy analyses, we observed that, in the presence of nuclear extract, intact VLPs partially disassemble, providing a mechanistic explanation to how the exogenous plasmid was packaged by these particles. Further, we provide evidence that capsids containing an IMPORTANCE Little is known about papillomavirus assembly biology due to the difficulties in propagating virus in vitro . The cell-free assembly method established in this paper reveals a new mechanism for viral genome packaging and will provide a tractable system for further dissecting papillomavirus assembly. The knowledge gained will increase our understanding of virus-host interactions, help to identify new targets for antiviral therapy, and allow for the development of new gene delivery systems based on in vitro -generated papillomavirus vectors.

We previously determined that human papillomavirus (HPV) virus-like particles (VLPs) and pseudovirions (PsV) did not, respectively, bind to or infect intact epithelium of the cervicovaginal tract. However, they strongly bound heparan sulfate proteoglycans (HSPG) on the basement membrane of disrupted epithelium and infected the keratinocytes that subsequently entered the disrupted site. We here report that HPV capsids (VLP and PsV) have the same restricted tropism for a wide variety of disrupted epithelial and mesothelial tissues, whereas intact tissues remain resistant to binding. However, the HPV capsids directly bind and infect most tumor-derived cell lines in vitro and have analogous tumor-specific properties in vivo, after local or intravenous injection, using orthotopic models for human ovarian and lung cancer, respectively. The pseudovirions also specifically infected implanted primary human ovarian tumors. Heparin and ι-carrageenan blocked binding and infection of all tumor lines tested, implying that tumor cell binding is HSPG-dependent. A survey using a panel of modified heparins indicates that N-sulfation and, to a lesser degree, O-6 sulfation of the surface HSPG on the tumors are important for HPV binding. Therefore, it appears that tumor cells consistently evolve HSPG modification patterns that mimic the pattern normally found on the basement membrane but not on the apical surfaces of normal epithelial or mesothelial cells. Consequently, appropriately modified HPV VLPs and/or PsV could be useful reagents to detect and potentially treat a remarkably broad spectrum of cancers.

Summary Background There is some evidence to suggest that one or two doses of the HPV vaccine provides similar protection to the three-dose regimen. The main aim of the study was to ascertain HPV-16/18 vaccine efficacy in both full and naive cohorts and to explore protection conferred against non-vaccine HPV types, by number of doses received. Methods Summary data from the Costa Rica Vaccine Trial (CVT; NCT00128661) and ~the PATRICIA trial (NCT001226810), two phase 3, double-blind, randomised controlled clinical trials of the HPV-16/18 AS04-adjuvanted vaccine in young women, were combined in a post-hoc analysis (GlaxoSmithKline [GSK] e-track number 202142) to investigate the efficacy of fewer than three doses of the HPV-16/18 vaccine after 4 years of follow-up. Women were randomly assigned to receive three doses of the HPV-16/18 vaccine or to a control vaccine; yet, some received fewer doses. After exclusion of women with less than 12 months of follow-up or those who were HPV-16/18 DNA-positive at enrolment (for the HPV-16/18 endpoint), we calculated vaccine efficacy against one-time detection of incident HPV infections after three, two, and one dose(s). The primary study endpoint was one-time detection of first incident HPV-16/18 infections accumulated during the follow-up phase. Findings We assessed vaccine efficacy against incident HPV-16/18 infection in the modified total vaccinated cohort (22 327 received three doses, 1185 two doses, 543 one dose). Vaccine efficacy against incident HPV-16/18 infections for three doses was 77·0% (95% CI 74·7–79·1), two doses was 76·0% (62·0–85·3), and one dose was 85·7% (70·7–93·7). Vaccine efficacy against incident HPV-31/33/45 infections for three doses was 59·7% (56·0–63·0), two doses was 37·7% (12·4–55·9), and one dose was 36·6% (–5·4 to 62·2). Vaccine efficacy against incident HPV-16/18 infection for two-dose women who received their second dose at 1 month was 75·3% (54·2–87·5) and 82·6% (42·3–96·1) for those who received the second dose at 6 months (CVT data only). Vaccine efficacy against HPV-31/33/45 for two-dose women who received their second dose at 6 months (68·1%, 27·0–87·0; CVT data only), but not those receiving it at one month (10·1%, −42·0 to 43·3), was similar to the three-dose group. Interpretation 4 years after vaccination of women aged 15–25 years, one and two doses of the HPV-16/18 vaccine seem to protect against cervical HPV-16/18 infections, similar to the protection provided by the three-dose schedule. Two doses separated by 6 months additionally provided some cross-protection. These data argue for a direct assessment of one-dose efficacy of the HPV-16/18 vaccine. Funding US National Cancer Institute, National Institutes of Health Office of Research on Women's Health, and Ministry of Health of Costa Rica (CVT); GlaxoSmithKline Biologicals SA (PATRICIA).

To understand and compare the mechanisms of murine and human PV infection, we examined pseudovirion binding and infection of the newly described MusPV1 using the murine cervicovaginal challenge model. These analyses revealed primary tissue interactions distinct from those previously described for HPV16. Unlike HPV16, MusPV1 bound basement membrane (BM) in an HSPG-independent manner. Nevertheless, subsequent HSPG interactions were critical. L2 antibodies or low doses of VLP antibodies, sufficient to prevent infection, did not lead to disassociation of the MusPV1 pseudovirions from the BM, in contrast to previous findings with HPV16. Similarly, furin inhibition did not lead to loss of MusPV1 from the BM. Therefore, phylogenetically distant PV types differ in their initial interactions with host attachment factors, but initiate their lifecycle on the acellular BM. Despite these differences, these distantly related PV types displayed similar intracellular trafficking patterns and susceptibilities to biochemical inhibition of infection.

The Costa Rica Vaccine Trial (CVT) was a randomized clinical trial conducted between 2004 and 2010, which randomized 7466 women aged 18 to 25 to receive the bivalent HPV-16/18 vaccine or control Hepatitis-A vaccine. Participants were followed for 4 years with cross-over vaccination at the study end. In 2010 the long term follow-up (LTFU) study was initiated to evaluate the 10-year impact of HPV-16/18 vaccination, determinants of the immune response, and HPV natural history in a vaccinated population. Herein, the rationale, design and methods of the LTFU study are described, which actively follows CVT participants in the HPV-arm 6 additional years at biennial intervals (3 additional study visits for 10 years of total follow-up), or more often if clinically indicated. According to the initial commitment, women in the Hepatitis-A arm were offered HPV vaccination at cross-over; they were followed 2 additional years and exited from the study. 92% of eligible CVT women accepted participation in LTFU. To provide underlying rates of HPV acquisition and cervical disease among unvaccinated women to compare with the HPV-arm during LTFU, a new unvaccinated control group (UCG) of women who are beyond the age generally recommended for routine vaccination was enrolled, and will be followed by cervical cancer screening over 6 years. To form the UCG, 5000 women were selected from a local census, of whom 2836 women (61% of eligible women) agreed to participate. Over 90% of participants complied with an interview, blood and cervical specimen collection. Evaluation of comparability between the original (Hepatitis-A arm of CVT) and new (UCG) control groups showed that women's characteristics, as well as their predicted future risk for cervical HPV acquisition, were similar, thus validating use of the UCG. LTFU is poised to comprehensively address many important questions related to long-term effects of prophylactic HPV vaccines.

No herpes simplex virus 2 (HSV-2) vaccine has been licensed for use in humans. HSV-2 glycoproteins B (gB) and D (gD) are targets of neutralizing antibodies and T cells, but clinical trials involving intramuscular (i.m.) injection of HSV-2 gB and gD in adjuvants have not been effective. Here we evaluated intravaginal (ivag) genetic immunization of C57BL/6 mice with a replication-defective human papillomavirus pseudovirus (HPV PsV) expressing HSV-2 gB (HPV-gB) or gD (HPV-gD) constructs to target different subcellular compartments. HPV PsV expressing a secreted ectodomain of gB (gBsec) or gD (gDsec), but not PsV expressing a cytoplasmic or membrane-bound form, induced circulating and intravaginal-tissue-resident memory CD8 + T cells that were able to secrete gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) as well as moderate levels of serum HSV neutralizing antibodies. Combined immunization with HPV-gBsec and HPV-gDsec (HPV-gBsec/gDsec) vaccines conferred longer survival after vaginal challenge with HSV-2 than immunization with HPV-gBsec or HPV-gDsec alone. HPV-gBsec/gDsec ivag vaccination was associated with a reduced severity of genital lesions and lower levels of viral shedding in the genital tract after HSV-2 challenge. In contrast, intramuscular vaccination with a soluble truncated gD protein (gD2t) in alum and monophosphoryl lipid A (MPL) elicited high neutralizing antibody titers and improved survival but did not reduce genital lesions and viral shedding. Vaccination combining ivag HPV-gBsec/gDsec and i.m. gD2t-alum-MPL improved survival and reduced genital lesions and viral shedding. Finally, high levels of circulating HSV-2-specific CD8 + T cells, but not serum antibodies, correlated with reduced viral shedding. Taken together, our data underscore the potential of HPV PsV as a platform for a topical mucosal vaccine to control local manifestations of primary HSV-2 infection. IMPORTANCE Genital herpes is a highly prevalent chronic disease caused by HSV infection. To date, there is no licensed vaccine against HSV infection. This study describes intravaginal vaccination with a nonreplicating HPV-based vector expressing HSV glycoprotein antigens. The data presented in this study underscore the potential of HPV-based vectors as a platform for the induction of genital-tissue-resident memory T cell responses and the control of local manifestations of primary HSV infection.

The Costa Rica Vaccine Trial (CVT), a phase III randomized clinical trial, provided the initial data that one dose of the HPV vaccine could provide durable protection against HPV infection. Although the study design was to administer all participants three doses of HPV or control vaccine, 20% of women did not receive the three-dose regimens, mostly due to involuntary reasons unrelated to vaccination. In 2011, we reported that a single dose of the bivalent HPV vaccine could be as efficacious as three doses of the vaccine using the endpoint of persistent HPV infection accumulated over the first four years of the trial; findings independently confirmed in the GSK-sponsored PATRICIA trial. Antibody levels after one dose, although lower than levels elicited by three doses, were 9-times higher than levels elicited by natural infection. Importantly, levels remained essentially constant over at least seven years, suggesting that the observed protection provided by a single dose might be durable. Much work has been done to assure these non-randomized findings are valid. Yet, the group of recipients who received one dose of the bivalent HPV vaccine in the CVT and PATRICIA trials was small and not randomly selected nor blinded to the number of doses received. The next phase of research is to conduct a formal randomized, controlled trial to evaluate the protection afforded by a single dose of HPV vaccine. Complementary studies are in progress to bridge our findings to other populations, and to further document the long-term durability of antibody response following a single dose.

The human papillomavirus pseudovirions (HPV-PsVs) approach is an effective gene-delivery system that can prime or boost an immune response in the vaginal tract of nonhuman primates and mice. Intravaginal vaccination with HPV-PsVs expressing SIV genes, combined with an i.m. gp120 protein injection, induced humoral and cellular SIV-specific responses in macaques. Priming systemic immune responses with i.m. immunization with ALVAC-SIV vaccines, followed by intravaginal HPV-PsV–SIV/gp120 boosting, expanded and/or recruited T cells in the female genital tract. Using a stringent repeated low-dose intravaginal challenge with the highly pathogenic SIVmac251, we show that although these regimens did not demonstrate significant protection from virus acquisition, they provided control of viremia in a number of animals. High-avidity Ab responses to the envelope gp120 V1/V2 region correlated with delayed SIVmac251 acquisition, whereas virus levels in mucosal tissues were inversely correlated with antienvelope CD4+ T cell responses. CD8+ T cell depletion in animals with controlled viremia caused an increase in tissue virus load in some animals, suggesting a role for CD8+ T cells in virus control. This study highlights the importance of CD8+ cells and antienvelope CD4+ T cells in curtailing virus replication and antienvelope V1/V2 Abs in preventing SIVmac251 acquisition.

Two HPV virus-like particle (VLP) vaccines, HPV-16/18 (GlaxoSmithKline, Cervarix®) and HPV-6/11/16/18 (Merck, Gardasil®), are currently licensed in the United States. Given the similar antigenic content but different adjuvant formulations in the 2 vaccines, they provide an efficient method for evaluating adjuvants and comparing the kinetics of the innate and adaptive immune responses. We randomized women to receive either Cervarix® or Gardasil®, followed 6 month vaccination delivery schedules per manufacturer's recommendations, and analyzed the humoral immune response, T cell response, and circulating plasma cytokine levels in response to vaccination. Cervarix® recipients had higher anti-HPV-16 antibody and neutralization titers at month 7, and elevated anti-HPV-18 antibody and neutralization titers at months 7 and 12. Antibody avidity was similar for the 2 vaccines. HPV-31 was the only phylogenetically related non-vaccine HPV type, for which there is evidence of cross-protection, to be cross-neutralized and only in response to Cervarix®. Comparing CD4+ T cell cytokine responses at month 12, there was a trend of increased levels of IL-2 and TNF-α in the Cervarix® groups versus the Gardasil® groups that was consistent across all 4 tested HPV types (16/18/33/45). Elevated levels of circulating plasma cytokine/chemokines were observed post first vaccination in Gardasil® recipients and proinflammatory cytokines were elevated following 1st and 3rd Cervarix® vaccinations. Cervarix® and Gardasil® are both highly immunogenic vaccines. Higher antibody levels and CD4 T cell responses were achieved with Cervarix® after 3 doses, although similar affinity maturation was measured for the 2 vaccines. The clinical implications of the differences in immune responses are unknown.

The glutathione S-transferase (GST)-L1 multiplex serology assay has favorable properties for use in clinical trials and epidemiologic studies, including low cost, high throughput capacity, and low serum volume requirement. Therefore, we evaluated the GST-L1 assay as a measure of HPV16/18 vaccine immunogenicity. Our study population included 65 women selected from the Costa Rica Vaccine Trial who received the bivalent HPV16/18 virus-like particle (VLP) vaccine at the recommended 0/1/6-month schedule. We tested replicate serum samples from months 0/1/12 (i.e., after 0/1/3 doses) by GST-L1 and 3 other commonly used serology assays, VLP-ELISA, SEAP-NA, and cLIA. We calculated the percentage of women seropositive by GST-L1 by time point and HPV type (14 HPV types), and compared GST-L1 to other assays using Spearman rank correlation coefficients. After 1 vaccine dose, seropositivity by GST-L1 was 40% each for HPV16 and HPV18, increasing to 100% and 98%, respectively, after 3 doses. Seropositivity after 3 doses ranged from 32% to 69% for HPV types 31/33/45, for which partial vaccine efficacy is reported, though increases also occurred for types with no evidence for cross-protection (e.g., HPV77). GST-L1 correlated best after 3 doses with VLP-ELISA (HPV16 and HPV18 each ρ = 0.72) and SEAP-NA (HPV16 ρ = 0.65, HPV18 ρ = 0.71) (all P

Vulvar cancer is rare, accounting for approximately 4% of gynecological malignancies worldwide [1]. However, the incidence of vulvar cancer has been increasing, particularly in young women [2, 3]. In the United States from 2000 to 2009, the incidence of vulvar cancer has significantly increased among both white and African American women; 1.4% and 0.9% annual percentage change, respectively [3]. This increase is believed to be due to a rise in human papillomavirus (HPV) infection [2, 4–6]. Worldwide, it is estimated that HPV infection is the causative agent in approximately 43% of vulvar cancers [7]. HPV 16 and 18 infections combined account for 93% of HPV-associated vulvar cancers [8]; thus, prophylactic vaccination has the potential to reduce the incidence of vulvar cancer. Two vaccines prevent HPV 16 and 18 infections at the cervix: the bivalent HPV16/18 vaccine Cervarix®, GlaxoSmithKline Vaccines [GSK]) [9] and the quadrivalent HPV6/11/16/18 vaccine (Gardasil™, Merck and Co, Inc) [10]. Data presented in abstract form for the bivalent vaccine reported a 75% reduction in HPV16/18-associated vulvar/vaginal precursor lesions (a combined endpoint) among vaccinated women compared to controls [11]. For the quadrivalent vaccine, high (>95%) vaccine efficacy (VE) against HPV16/18-associated vulvar intraepithelial neoplasia grades 1, 2, and 3 was demonstrated [10], garnering an indication from the US Food and Drug Administration (FDA) for prevention of vulvar cancer. VE against HPV16/18 infections at the vulva has yet to be reported. Efficacy against HPV16/18-associated vulvar lesions was demonstrated by both pharmaceutical vaccine trials using HPV DNA testing of vulvar lesions, which represented a small subset of the total trial population [10, 11]. Given that VE against HPV-associated lesions is the result of prevention of HPV infection, we reasoned that use of a virologic endpoint for the estimation of vulvar VE would provide additional novel information on an intermediate endpoint on the pathway to cancer. Likewise, perhaps due to the rarity of HPV-associated vulvar cancer, only 6 studies have been published on the epidemiology of vulvar HPV infection in cancer-free women [12–17] and only 1 study reported risk factors associated with high-risk HPV infection of the vulva [17]. To address the limited knowledge of vulvar VE as well as the epidemiology of vulvar HPV infection, we implemented a vulvar specimen collection at the final (year 4), randomized blinded study visit of the Costa Rica Vaccine Trial (CVT). The goals of this value-added analysis were to (1) estimate the reduction of prevalent HPV16/18 infections at the vulva compared to cervix among HPV vaccinated women compared to controls 4 years after vaccination, and (2) characterize the prevalence of and risk factors for vulvar HPV infection in the control arm of this study population.

Genetically modified bacterial flagellin (Fla), a Toll-like receptor-5 (TLR5) ligand, was evaluated as a fusion partner for human papillomavirus (HPV) L2-based immunogens in two animal challenge models; either cutaneous inoculation of rabbits with HPV ‘quasivirions’ containing cottontail rabbit papillomavirus (CRPV) genomes that induce warts, or intra-vaginal inoculation of mice with HPV ‘pseudovirions’ encapsidating a luciferase reporter plasmid and measurement of bioluminescence to determine infectivity. An Escherichia coli production system was developed for flagellin-L2 (Fla-L2) fusions containing either monomeric HPV-16 L2 a.a. 11( × 11–200) or oligomeric L2 comprising a fusion of the a.a. 11–88 peptides of five (Fla∼5 × 11–88) or eight (Fla∼8 × 11–88) genital HPV types. Immunogenicity and bioactivity of Fla-L2 constructs were assessed using an in vitro neutralization and cell-based TLR-5 binding assay, respectively. Efficacy was evaluated following active immunization of rabbits or mice administered 3 intramuscular doses of Fla-L2 recombinants without exogenous adjuvant, followed by challenge. In addition, passive immunization studies of naive rabbits with serial dilutions of pooled immune sera were used to determine End-Point Protection Titers (EPPT) for each formulation against a broader spectrum of HPV quasivirions. Efficacy was assessed for up to 10 weeks on the basis of wart volume induced following challenge and results compared to licensed L1-VLP vaccines (Gardasil and Cervarix). Following active immunization at doses as low as 1 μg, Fla-L2 fusions afforded complete protection against infection (mice) and disease (rabbits) following either homologous or heterologous HPV challenge. Passive immunization with anti-L2 immune sera discriminated between the different vaccine candidates under evaluation, demonstrated the protective role of antibody and suggested the superiority of this oligomeric L2-TLR5 agonist fusion approach compared to L1-based vaccines in its ability to cross-protect against non-vaccine HPV types.

Full-length genomic DNA of the recently identified laboratory mouse papillomavirus 1 (MusPV1) was synthesized in vitro and was used to establish and characterize a mouse model of papillomavirus pathobiology. MusPV1 DNA, whether naked or encapsidated by MusPV1 or human papillomavirus 16 (HPV 16) capsids, efficiently induced the outgrowth of papillomas as early as 3 weeks after application to abraded skin on the muzzles and tails of athymic NCr nude mice. High concentrations of virions were extracted from homogenized papillomatous tissues and were serially passaged for >10 generations. Neutralization by L1 antisera confirmed that infectious transmission was capsid mediated. Unexpectedly, the skin of the murine back was much less susceptible to virion-induced papillomas than the muzzle or tail. Although reporter pseudovirions readily transduced the skin of the back, infection with native MusPV1 resulted in less viral genome amplification and gene expression on the back, including reduced expression of the L1 protein and very low expression of the L2 protein, results that imply skin region-specific control of postentry aspects of the viral life cycle. Unexpectedly, L1 protein on the back was predominantly cytoplasmic, while on the tail the abundant L1 was cytoplasmic in the lower epithelial layers and nuclear in the upper layers. Nuclear localization of L1 occurred only in cells that coexpressed the minor capsid protein, L2. The pattern of L1 protein staining in the infected epithelium suggests that L1 expression occurs earlier in the MusPV1 life cycle than in the life cycle of high-risk HPV and that virion assembly is regulated by a previously undescribed mechanism.

Infection with human papillomavirus (HPV) is recognized as one of the major causes of infection-related cancer worldwide, as well as the causal factor in other diseases. Strong evidence for a causal etiology with HPV has been stated by the International Agency for Research on Cancer for cancers of the cervix uteri, penis, vulva, vagina, anus and oropharynx (including base of the tongue and tonsils). Of the estimated 12.7 million new cancers occurring in 2008 worldwide, 4.8% were attributable to HPV infection, with substantially higher incidence and mortality rates seen in developing versus developed countries. In recent years, we have gained tremendous knowledge about HPVs and their interactions with host cells, tissues and the immune system; have validated and implemented strategies for safe and efficacious prophylactic vaccination against HPV infections; have developed increasingly sensitive and specific molecular diagnostic tools for HPV detection for use in cervical cancer screening; and have substantially increased global awareness of HPV and its many associated diseases in women, men, and children. While these achievements exemplify the success of biomedical research in generating important public health interventions, they also generate new and daunting challenges: costs of HPV prevention and medical care, the implementation of what is technically possible, socio-political resistance to prevention opportunities, and the very wide ranges of national economic capabilities and health care systems. Gains and challenges faced in the quest for comprehensive control of HPV infection and HPV-related cancers and other disease are summarized in this review. The information presented may be viewed in terms of a reframed paradigm of prevention of cervical cancer and other HPV-related diseases that will include strategic combinations of at least four major components: 1) routine introduction of HPV vaccines to women in all countries, 2) extension and simplification of existing screening programs using HPV-based technology, 3) extension of adapted screening programs to developing populations, and 4) consideration of the broader spectrum of cancers and other diseases preventable by HPV vaccination in women, as well as in men. Despite the huge advances already achieved, there must be ongoing efforts including international advocacy to achieve widespread-optimally universal-implementation of HPV prevention strategies in both developed and developing countries. This article summarizes information from the chapters presented in a special ICO Monograph 'Comprehensive Control of HPV Infections and Related Diseases' Vaccine Volume 30, Supplement 5, 2012. Additional details on each subtopic and full information regarding the supporting literature references may be found in the original chapters. (C) 2013 Elsevier Ltd. All rights reserved.

Background: We investigated the role of antibody responses as potential mechanism for the cross-protective vaccine-efficacies (VE) observed from randomized clinical trials of the HPV16/18 bivalent vaccine. Results: HPV31 cases had lower HPV16 antibody levels than controls (OR4th quartile compared with 1st quartile = 0.63; 95%CI: 0.36–1.08; p-trend = 0.03). HPV31 cases were also less likely to have detectable HPV31 neutralization, and HPV16 avidity than controls. No statistically significant differences by HPV18 antibody or HPV45 neutralization were observed among HPV45 cases and controls. Protection against HPV58 was not associated with any of the markers, confirming the specificity of our findings. Methods: Samples are from three-dose HPV vaccine recipients from the Costa Rica HPV16/18 vaccine trial. Women with a new HPV31, HPV45, or HPV58 infections over four years of follow-up were compared with randomly selected control women—with no new infection with HPV31/45/58—with respect to HPV16 and HPV18 antibody, HPV31, HPV45, and HPV58 neutralization, and HPV16 avidity. Conclusions: High HPV16 levels and avidity, and the ability to neutralize HPV31 were associated with protection against newly detected HPV31 infections, suggesting that the partial VE demonstrated for HPV31 is likely to be mediated at least in part through antibodies induced by HPV16/18 vaccination.

Human papillomaviruses (HPV)-related cervical cancer is the second leading cause of cancer death in women worldwide. Despite active development, HPV E6/E7 oncogene-specific therapeutic vaccines have had limited clinical efficacy to date. Here, we report that intravaginal (IVAG) instillation of CpG-ODN (TLR9 agonist) or poly-(I:C) (TLR3 agonist) after subcutaneous E7 vaccination increased ∼fivefold the number of vaccine-specific interferon-γ-secreting CD8 T cells in the genital mucosa (GM) of mice, without affecting the E7-specific systemic response. The IVAG treatment locally increased both E7-specific and total CD8 T cells, but not CD4 T cells. This previously unreported selective recruitment of CD8 T cells from the periphery by IVAG CpG-ODN or poly-(I:C) was mediated by TLR9 and TLR3/melanoma differentiation-associated gene 5 signaling pathways, respectively. For CpG, this recruitment was associated with a higher proportion of GM-localized CD8 T cells expressing both CCR5 and CXCR3 chemokine receptors and E-selectin ligands. Most interestingly, IVAG CpG-ODN following vaccination led to complete regression of large genital HPV tumors in 75% of mice, instead of 20% with vaccination alone. These findings suggest that mucosal application of immunostimulatory molecules might substantially increase the effectiveness of parenterally administered vaccines.Mucosal Immunology advance online publication 12 September 2012; doi:10.1038/mi.2012.83.

In this study, we report that gamma interferon (IFN-γ) treatment, but not IFN-α, -β, or -λ treatment, dramatically decreased infection of human papillomavirus 16 (HPV16) pseudovirus (PsV). In a survey of 20 additional HPV and animal papillomavirus types, we found that many, but not all, PsV types were also inhibited by IFN-γ. Microscopic and biochemical analyses of HPV16 PsV determined that the antiviral effect was exerted at the level of endosomal processing of the incoming capsid and depended on the JAK2/STAT1 pathway. In contrast to infection in the absence of IFN-γ, where L1 proteolytic products are produced during endosomal capsid processing and L2/DNA complexes segregate from L1 in the late endosome and travel to the nucleus, IFN-γ treatment led to decreased L1 proteolysis and retention of L2 and the viral genome in the late endosome/lysosome. PsV sensitivity or resistance to IFN-γ treatment was mapped to the L2 protein, as determined with infectious hybrid PsV, in which the L1 protein was derived from an IFN-γ-sensitive HPV type and the L2 protein from an IFN-γ-insensitive type or vice versa. IMPORTANCE A subset of HPV are the causative agents of many human cancers, most notably cervical cancer. This work describes the inhibition of infection of multiple HPV types, including oncogenic types, by treatment with IFN-γ, an antiviral cytokine that is released from stimulated immune cells. Exposure of cells to IFN-γ has been shown to trigger the expression of proteins with broad antiviral effector functions, most of which act to prevent viral transcription or translation. Interestingly, in this study, we show that infection is blocked at the early step of virus entry into the host cell by retention of the minor capsid protein, L2, and the viral genome instead of trafficking into the nucleus. Thus, a novel antiviral mechanism for IFN-γ has been revealed.

Human papillomavirus (HPV) causes greater than 5% of cancers worldwide, including all cervical cancers and an alarmingly increasing proportion of oropharyngeal cancers (OPCs). Despite markedly reduced cervical cancer incidence in industrialized nations with organized screening programs, cervical cancer remains the second most common cause of death from cancer in women worldwide, as developing countries lack resources for universal, high-quality screening. In the United States, HPV-related OPC is only 1 of 5 cancers with a rising incidence since 1975 and now has taken over the cervix as the most common site of HPV-related cancer. Similar trends follow throughout North America and Europe. The need for early detection and prevention is paramount. Despite the common etiologic role of HPV in the development of cervical cancer and HPV-associated OPC, great disparity exists between incidence, screening modalities (or lack thereof), treatment, and prevention in these 2 very distinct cohorts. These differences in cervical cancer and HPV-associated OPC and their impact are discussed here. Cancer 2017;123:2219-2229. © 2017 American Cancer Society.

Bladder cancer is the second most common urological malignancy in the world. In 70% of cases it is initially diagnosed as non-muscle-invasive bladder cancer (NMIBC) and it is amenable to local treatments, with intravesical (IVES) Bacillus-Calmette-Guerin (BCG) immunotherapy being routinely used after transurethral resection of the lesion. However, this treatment is associated with significant side-effects and treatment failures, highlighting the necessity of novel strategies. One potent approach is the suicide-gene mediated therapy/prodrug combination, provided tumor-specificity can be ensured and anti-tumor immune responses induced. Using the mouse syngeneic orthotopic MB49-bladder tumor model, here we show that IVES human papillomavirus non-replicative pseudovirions (PsV) can pseudoinfect tumors with a ten-fold higher efficacy than normal bladders. In addition, PsV carrying the suicide-gene herpes-simplex virus thymidine kinase (PsV-TK) combined to Ganciclovir (GCV) led to immunogenic cell-death of tumor cells in vitro and to MB49-specific CD8 T-cells in vivo. This was associated with reduction in bladder-tumor growth and increased mice survival. Altogether, our data show that IVES PsV-TK/GCV may be a promising alternative or combinatory treatment for NMIBC.

Background Virus-like particles (VLPs) represent a significant advance in the development of subunit vaccines, combining high safety and efficacy. Their particulate nature and dense repetitive subunit organization makes them ideal scaffolds for display of vaccine antigens. Traditional approaches for VLP-based antigen display require labor-intensive trial-and-error optimization, and often fail to generate dense antigen display. Here we utilize the split-intein (SpyTag/SpyCatcher) conjugation system to generate stable isopeptide bound antigen-VLP complexes by simply mixing of the antigen and VLP components. Results Genetic fusion of SpyTag or SpyCatcher to the N-terminus and/or C-terminus of the Acinetobacter phage AP205 capsid protein resulted in formation of stable, nonaggregated VLPs expressing one SpyCatcher, one SpyTag or two SpyTags per capsid protein. Mixing of spy-VLPs with eleven different vaccine antigens fused to SpyCatcher or SpyTag resulted in formation of antigen-VLP complexes with coupling efficiencies (% occupancy of total VLP binding sites) ranging from 22–88 %. In mice, spy-VLP vaccines presenting the malaria proteins Pfs25 or VAR2CSA markedly increased antibody titer, affinity, longevity and functional efficacy compared to corresponding vaccines employing monomeric proteins. The spy-VLP vaccines also effectively broke B cell self-tolerance and induced potent and durable antibody responses upon vaccination with cancer or allergy-associated self-antigens (PD-L1, CTLA-4 and IL-5). Conclusions The spy-VLP system constitutes a versatile and rapid method to develop highly immunogenic VLP-based vaccines. Our data provide proof-of-concept for the technology’s ability to present complex vaccine antigens to the immune system and elicit robust functional antibody responses as well as to efficiently break B cell self-tolerance. The spy-VLP-system may serve as a generic tool for the cost-effective development of effective VLP-vaccines against both infectious- and non-communicable diseases and could facilitate rapid and unbiased screening of vaccine candidate antigens. Electronic supplementary material The online version of this article (doi:10.1186/s12951-016-0181-1) contains supplementary material, which is available to authorized users.

End of study analyses of the phase III trials of prophylactic human papillomavirus (HPV) virus-like particle (VLP) vaccines in young women are now largely completed. Two distinct vaccines were evaluated, Gardasil® (Merck & Co., Whitehouse Station, NJ USA) a quadrivalent vaccine containing VLPs of types 6, 11, 16 and 18 and Cervarix® (GlaxoSmithKline Biologicals, Rixensart, Belgium), a bivalent vaccine containing VLPs of types 16 and 18. Both vaccines exhibited excellent safety and immunogenicity profiles. The vaccines also demonstrated remarkably high and similar efficacy against the vaccine-targeted types for a range of cervical endpoints from persistent infection to cervical intraepithelial neoplasia grade 3 (CIN3) in women naïve to the corresponding type at the time of vaccination. However, protection from incident infection or disease from non-vaccine types was restricted, and the vaccines had no effect on prevalent infection or disease. Gardasil® also demonstrated strong protection against genital warts and vulvar/vaginal neoplasia associated with the vaccine types. In other trials, Gardasil® protected mid-adult women from incident infection and CIN caused by the vaccine types and protected men for incident infection, genital warts and anal intraepithelial neoplasia by the vaccine types. Cervarix® protected against vaccine-targeted anal infections in women in an end of study evaluation. For practical reasons, efficacy studies have not been conducted in the primary target populations of current vaccination programs, adolescent girls and boys. However, immunogenicity bridging studies demonstrating excellent safety and strong immune responses in adolescence, coupled with the documentation of durable antibody responses and protection in young adults, leads to an optimistic projection of the effectiveness of the vaccines in adolescent vaccination programs. Taken together, the excellent clinical trial results strongly support the potential of the vaccines as high value public health interventions and justify their widespread implementation to prevent anogenital HPV infections and their associated neoplasia. This article forms part of a special supplement entitled “Opportunities for comprehensive control of HPV infections and related diseases” Vaccine Volume 30, Supplement X, 2012.

An estimated 5% of human cancers are caused by human papillomavirus (HPV) infections, and most of these cancers are of the cervix. Two prophylactic HPV vaccines that target the two most oncogenic virus types, HPV16 and HPV18, are now commercially available. In controlled clinical trials, the vaccines proved to be effective at preventing incident anogenital infection and the associated neoplastic disease that is induced by these virus types. Here, we highlight the specific aspects of HPV biology and vaccine composition that are likely to contribute to the efficacy of these vaccines, and we discuss how these particular features might or might not be relevant for the development of effective vaccines against other sexually transmitted viruses such as HIV and herpes simplex virus (HSV).

Papillomavirus L2-based vaccines have generally induced low-level or undetectable neutralizing antibodies in standardin vitroassays yet typically protect well againstin vivoexperimental challenge in animal models. Herein we document that mice vaccinated with an L2 vaccine comprising a fusion protein of the L2 amino acids 11 to 88 of human papillomavirus type 16 (HPV16), HPV18, HPV1, HPV5, and HPV6 were uniformly protected from cervicovaginal challenge with HPV16 pseudovirus, but neutralizing antibodies against HPV16, -31, -33, -45, or -58 were rarely detected in their sera using a standardin vitroneutralization assay. To address this discrepancy, we developed a neutralization assay based on anin vitroinfectivity mechanism that more closely mimics thein vivoinfectious process, specifically by spaciotemporally separating primary and secondary receptor engagement and correspondingly by altering the timing of exposure of the dominant L2 cross-neutralizing epitopes to the antibodies. With the new assay, titers in the 100 to 10,000 range were measured for most sera, whereas undetectable neutralizing activities were observed with the standard assay.In vitroneutralizing titers measured in the serum of mice after passive transfer of rabbit L2 immune serum correlated with protection from cervicovaginal challenge of the mice. This “L2-based”in vitroneutralization assay should prove useful in critically evaluating the immunogenicity of L2 vaccine candidates in preclinical studies and future clinical trials.

Human papillomavirus (HPV)-related cancers are a major worldwide public health concern. Virtually all cervical cancer is HPV related, with 70% caused by HPV16 and -18. Variable proportions of certain noncervical cancers (e.g., anal, vulvar, and oropharyngeal) are HPV related; more than 90% of the HPV-related ones are caused by HPV16, -18. The HPV-related cancers are dominated by cervical cancer in the developing world, where cervical cancer screening is limited. In this setting, widespread uptake of current HPV vaccines by adolescent girls could reduce this cancer's incidence and mortality by approximately two-thirds, with cost-effective screening programs of adult women having the potential to reduce mortality more rapidly. In the industrialized world, some noncervical HPV-related cancers, especially oropharyngeal, are rapidly increasing, and now rival the incidence of cervical cancer, whose rates continue to decline thanks to established cervical screening programs. Therefore, reducing HPV-associated noncervical cancers with HPV vaccination has greater importance in the industrialized world, especially because there are no approved screening programs for these cancers. Preventing the substantial number of noncervical HPV cancers in men will require either “herd” immunity through high-vaccination rates in females or male vaccination. Current HPV vaccination can complement cervical screening in protecting against cervical cancer and may permit the safe reduction of screening intensity in industrialized countries. Second-generation HPV vaccines (active against a broader array of cervical cancer–related HPV types) could prevent an even higher proportion of cervical precancer and cancer and might permit further reductions in screening intensity. Cancer Prev Res; 5(1); 18–23. ©2012 AACR.

The available virus-like particle (VLP)-based prophylactic vaccines against specific human papillomavirus (HPV) types afford close to 100% protection against the type-associated lesions and disease. Based on papillomavirus animal models, it is likely that protection against genital lesions in humans is mediated by HPV type-restricted neutralizing antibodies that transudate or exudate at the sites of genital infection. However, a correlate of protection was not established in the clinical trials because few disease cases occurred, and true incident infection could not be reliably distinguished from the emergence or reactivation of prevalent infection. In addition, the current assays for measuring vaccine-induced antibodies, even the gold standard HPV pseudovirion (PsV) in vitro neutralization assay, may not be sensitive enough to measure the minimum level of antibodies needed for protection. Here, we characterize the recently developed model of genital challenge with HPV PsV and determine the minimal amounts of VLP-induced neutralizing antibodies that can afford protection from genital infection in vivo after transfer into recipient mice. Our data show that serum antibody levels >100-fold lower than those detectable by in vitro PsV neutralization assays are sufficient to confer protection against an HPV PsV genital infection in this model. The results clearly demonstrate that, remarkably, the in vivo assay is substantially more sensitive than in vitro PsV neutralization and thus may be better suited for studies to establish correlates of protection.

The major capsid protein (L1) of human papillomaviruses (HPV) expressed in heterologous systems assembles into virus-like particles (VLPs). We report cloning and expression of codon optimized HPV L1 genes of the two high-risk HPV types 16 and 18 in methylotropic yeast, Pichia pastoris. The VLPs produced in P. pastoris were subjected to three step purification method involving density gradient centrifugations and size exclusion chromatography. The enriched VLPs were characterized using conformation-specific monoclonal antibodies in ELISA and by transmission electron microscopy. Mice immunized with a bivalent HPV16 and HPV18 VLPs developed high serum antibody titers to both HPV types that persisted for 190 days post vaccination. Serum of mice immunized with the HPV-VLP preparations could neutralize homologous pseudoviruses in an in vitro assays. Our results demonstrate that the L1 proteins expressed in P. pastoris fold properly as evidenced by assembly into VLPs and induction of type-specific neutralizing antibody response in mice. This work constitutes a step towards developing an alternate production platform for generating an affordable HPV vaccine to meet the needs of developing countries.

Cervical cancer results from infection with high-risk type human papillomaviruses (HPV). Therapeutic vaccines aiming at controlling existing genital HPV infections and associated lesions are usually tested in mice with HPV-expressing tumor cells subcutaneously implanted into their flank. However, effective vaccine-induced regression of these ectopic tumors strongly contrasts with the poor clinical results of these vaccines produced in patients with HPV-associated genital neoplasia. To assess HPV therapeutic vaccines in a more relevant setting, we have, here, established an orthotopic mouse model where tumors in the genital mucosa (GM) develop after an intravaginal instillation of HPV16 E6/E7-expressing tumor cells transduced with a luciferase-encoding lentiviral vector for in vivo imaging of tumor growth. Tumor take was 80-90% after nonoxynol-9 induced damage of the epithelium. Tumors remained localized in the genital tract, and histological analysis showed that most tumors grew within the squamous epithelium of the vaginal wall. Those tumors induced (i) E7-specific CD8 T cells restricted to the GM and draining lymph nodes, in agreement with their mucosal location and (ii) high Foxp3+ CD4+ infiltrates, similarly to those found in natural non-regressing HPV lesions. This novel genital HPV-tumor model by requiring GM homing of vaccine-induced immune responses able to overcome local immuno-suppression may be more representative of the situation occurring in patients upon therapeutic vaccination.

Multidose regimens are recommended for all prophylactic subunit vaccines. Recent findings from clinical trials of an human papillomavirus virus-like particle vaccine suggest that it may be possible to develop effective single-dose subunit vaccines. The broad implications of these findings are discussed, and the importance of antigen structure and adjuvant in achieving this goal is considered. In conclusion, we argue for the inclusion of single-dose arms in future trials of vaccines, especially if they are based on induction of antibodies by virus-like displayed antigens.

SummaryUsing a human papillomavirus (HPV) cervicovaginal murine challenge model, we microscopically examined the in vivo mechanisms of L1 virus-like particle (VLP) and L2 vaccine-induced inhibition of infection. In vivo HPV infection requires an initial association with the acellular basement membrane (BM) to induce conformational changes in the virion that permit its association with the keratinocyte cell surface. By passive transfer of immune serum, we determined that anti-L1 antibodies can interfere with infection at two stages. Similarly to active VLP immunization, transfer of high L1 antibody concentrations prevented BM binding. However, in the presence of low concentrations of anti-L1, virions associated with the BM, but to the epithelial cell surface was not detected. Regardless of the concentration, L2 vaccine-induced antibodies allow BM association but prevent association with the cell surface. Thus, we have revealed distinct mechanisms of vaccine-induced inhibition of virus infection in vivo.

Mucosal immunization may be important for protection against pathogens whose transmission and pathogenesis target the mucosal tissue. The capsid proteins of human papillomavirus (HPV) confer tropism for the basal epithelium and can encapsidate DNA during self-assembly to form pseudovirions (PsVs). Therefore, we produced mucosal vaccine vectors by HPV PsV encapsidation of DNA plasmids expressing an experimental antigen derived from the M and M2 proteins of respiratory syncytial virus (RSV). Intravaginal (IVag) delivery elicited local and systemic M-M2-specific CD8+ T-cell and antibody responses in mice that were comparable to an approximately 10,000-fold higher dose of naked DNA. A single HPV PsV IVag immunization primed for M-M2-specific-IgA in nasal and vaginal secretions. Based on light emission and immunofluorescent microscopy, immunization with HPV PsV-encapsidated luciferase- and red fluorescent protein (RFP)-expressing plasmids resulted in transient antigen expression (

The immunogenicity of an antigen can be dramatically increased by displaying it in a dense, multivalent context, such as on the surface of a virus or virus-like particle (VLP). Here we describe a highly versatile VLP platform for peptide display based on VLPs of the RNA bacteriophage PP7. We show that this platform can be used for the engineered display of specific peptide sequences as well as for the construction of random peptide libraries. Peptides representing the FLAG epitope, the V3 loop of HIV gp120, and a broadly cross-type neutralizing epitope from L2, the minor capsid protein of Human Papillomavirus type 16 (HPV16), were inserted into an exposed surface loop of a form of PP7 coat protein in which the two identical polypeptides of coat were fused together to form a single-chain dimer. The recombinant proteins assembled into VLPs, displayed these peptides on their surfaces, and induced high-titer antibody responses. The single-chain dimer was also highly tolerant of random 6-, 8-, and 10-amino acid insertions. PP7 VLPs displaying the HPV16 L2 epitope generated robust anti-HPV16 L2 serum antibodies after intramuscular injection that protected mice from genital infection with HPV16 pseudovirus as well as a heterologous HPV pseudovirus type, HPV45. Thus, PP7 VLPs are well-suited for the display of a wide diversity of peptides in a highly immunogenic format.

Papillomaviruses represent a medically important virus family. Infection with a high-risk human papillomavirus type is a prerequisite for cervical carcinoma development. Infection by low-risk types may result in the generation of benign skin warts. It was recently found that infectious entry of these viruses is dependent upon a specific proteolytic event that occurs prior to viral endocytosis. Specifically, a proprotein convertase, furin or proprotein convertase 5/6, must cleave the minor capsid protein for infection to proceed. Here, an overview of what is currently known about this process is presented, and what we have learned about the papillomavirus lifecycle from these studies discussed. This work also has implications for further advances in papillomavirus vaccine development.