Project description:The ability to elicit cross-neutralizing antibodies makes human papillomavirus (HPV) L2 capsid protein a possible HPV vaccine. We examined and compared the humoral response of mice immunized with a HPV-16 L2 DNA vaccine or with HPV-16 L2 protein. The L2 DNA vaccine elicited a non-neutralizing antibody response unlike the L2 protein. L2 DNA vaccination suppressed the growth of L2-expressing C3 tumor cells, which is a T cell mediated effect, demonstrating that the lack of non-neutralizing antibody induction by L2 DNA was not caused by lack of T cell immunogenicity of the construct.
Project description:BackgroundFactors that lead human papillomavirus (HPV) infections to persist and progress to cancer are not fully understood. We evaluated co-factors for acquisition, persistence, and progression of non-HPV-16/18 infections among HPV-vaccinated women.MethodsWe analyzed 2153 women aged 18-25 years randomized to the HPV-vaccine arm of the Costa Rica HPV Vaccine Trial. Women were HPV DNA negative for all types at baseline and followed for approximately 11 years. Generalized estimating equation methods were used to account for correlated observations. Time-dependent factors evaluated were age, sexual behavior, marital status, hormonally related factors, number of full-term pregnancies (FTPs), smoking behavior, and baseline body mass index.ResultsA total of 1777 incident oncogenic non-HPV-16/18 infections were detected in 12 292 visits (average, 0.14 infections/visit). Age and sexual behavior-related variables were associated with oncogenic non-HPV-16/18 acquisition. Twenty-six percent of incident infections persisted for ≥1 year. None of the factors evaluated were statistically associated with persistence of oncogenic non-HPV-16/18 infections. Risk of progression to Cervical Intraepithelial Neoplasia grade 2 or worst (CIN2+) increased with increasing age (P for trend = .001), injectable contraceptive use (relative risk, 2.61 [95% confidence interval, 1.19-5.73] ever vs never), and increasing FTPs (P for trend = .034).ConclusionsIn a cohort of HPV-16/18-vaccinated women, age and sexual behavior variables are associated with acquisition of oncogenic non-HPV-16/18 infections; no notable factors are associated with persistence of acquired infections; and age, parity, and hormonally related exposures are associated with progression to CIN2+.
Project description:To substantiate cross-protection reported across AS04-adjuvanted bivalent human papillomavirus (HPV) vaccine (2vHPV) studies, we reevaluated vaccine effectiveness against type-specific HPV positivity as a function of phylogenetic distance to vaccine target types HPV-16 and -18. We provide evidence of sustained cross-protection up to 8 years postvaccination in a high-risk population in the Netherlands. Moreover, our findings suggest that genomic distance better explains cross-protection than distance measures based on capsid antigens only. Taken together, 2vHPV is predicted to provide partial cross-protection against HPV-31, -33, -35, -45, -52, and possibly -58, that is, acknowledged oncogenic types with close phylogenetic relationships to HPV-16 or -18.
Project description:Human papillomavirus (HPV) virus-like particle (VLP) vaccines were recently licensed. Although neutralizing Ab titers are thought to be the main effectors of protection against infection, early predictors of long-term efficacy are not yet defined and a comprehensive understanding of innate and adaptive immune responses to vaccination is still lacking. Here, microarrays were used to compare the gene expression signature in HPV-16 L1 VLP-stimulated PBMCs from 17 vaccine and 4 placebo recipients before vaccination and 1 mo after receiving the second immunization. Vaccination with a monovalent HPV-16 L1 VLP vaccine was associated with modulation of genes involved in the inflammatory/defense response, cytokine, IFN, and cell cycle pathways in VLP-stimulated PBMCs. Additionally, there was up-regulation of probesets associated with cytotoxic (GZMB, TNFSF10) and regulatory (INDO, CTLA4) activities. The strongest correlations with neutralizing Ab titers were found for cyclin D2 (CCND2) and galectin (LGALS2). Twenty-two differentially expressed probesets were selected for confirmation by RT-PCR in an independent sample set. Agreement with microarray data was seen for more than two-thirds of these probesets. Up-regulation of immune/defense response genes by HPV-16 L1 VLP, in particular, IFN-induced genes, was observed in PBMCs collected before vaccination, with many of these genes being further induced following vaccination. In conclusion, we identified important innate and adaptive response-related genes induced by vaccination with HPV-16 L1 VLP. Further studies are needed to identify gene expression signatures of immunogenicity and long-term protection with potential utility in prediction of long-term HPV vaccination outcomes in clinical trials.
Project description:Protection against oncogenic non-vaccine types (cross-protection) offered by human papillomavirus (HPV) vaccines may provide a significant medical benefit. Available clinical efficacy data suggest the two licensed vaccines (HPV-16/18 vaccine, GlaxoSmithKline Biologicals (GSK), and HPV-6/11/16/18 vaccine, Merck & Co., Inc.) differ in terms of protection against oncogenic non-vaccine HPV types -31/45. The immune responses induced by the two vaccines against these two non-vaccine HPV types (cross-reactivity) was compared in an observer-blind study up to Month 24 (18 mo post-vaccination), in women HPV DNA-negative and seronegative prior to vaccination for the HPV type analyzed (HPV-010 [NCT00423046]). Geometric mean antibody titers (GMTs) measured by pseudovirion-based neutralization assay (PBNA) and enzyme-linked immunosorbent assay (ELISA) were similar between vaccines for HPV-31/45. Seropositivity rates for HPV-31 were also similar between vaccines; however, there was a trend for higher seropositivity with the HPV-16/18 vaccine (13.0-16.7%) versus the HPV-6/11/16/18 vaccine (0.0-5.0%) for HPV-45 with PBNA, but not ELISA. HPV-31/45 cross-reactive memory B-cell responses were comparable between vaccines. Circulating antigen-specific CD4+ T-cell frequencies were higher for the HPV-16/18 vaccine than the HPV-6/11/16/18 vaccine (HPV-31 [geometric mean ratio [GMR] =2.0; p=0.0002] and HPV-45 [GMR=2.6; p=0.0092]), as were the proportion of T-cell responders (HPV-31, p=0.0009; HPV-45, p=0.0793). In conclusion, immune response to oncogenic non-vaccine HPV types -31/45 was generally similar for both vaccines with the exception of T-cell response which was higher with the HPV-16/18 vaccine. Considering the differences in cross-protective efficacy between the two vaccines, the results might provide insights into the underlying mechanism(s) of protection.
Project description:Human papillomaviruses (HPVs) are the causative factor for >90% of cervical cancers and 25% of head and neck cancers. The incidence of HPV positive (+) head and neck squamous cell carcinomas has greatly increased in the last 30 years. E6 and E7 are the two key viral oncoproteins that induce and propagate cellular transformation. An immune response generated during cisplatin/radiation therapy improves tumor clearance of HPV(+) cancers. Augmenting this induced response during therapy with an adenoviral HPV16 E6/E7 vaccine improves long-term survival in pre-clinical models. Here, we describe the generation of an HPV16 E6/E7 construct, which contains mutations that render E6/E7 non-oncogenic, while preserving antigenicity. These mutations do not allow E6/E7 to degrade p53, pRb, PTPN13, or activate telomerase. Non-oncogenic E6/E7 (E6(?)/E7(?)) expressed as a stable integrant, or in the [E1-, E2b-] adenovirus, lacks the ability to transform human cells while retaining the ability to induce an HPV-specific immune response. Moreover, E6(?)/E7(?) plus chemotherapy/radiation statistically enhances clearance of established HPV(+) cancer in vivo.
Project description:Both the Human papillomavirus (HPV) major (L1) and minor (L2) capsid proteins have been well investigated as potential vaccine candidates. The L1 protein first oligomerizes into pentamers, and these capsomers assemble into virus-like particles (VLPs) that are highly immunogenic. Here we examine the potential of using HPV type 16 (HPV-16) L1 subunits to display a well-characterized HPV-16 L2 epitope (LVEETSFIDAGAP), which is a common-neutralizing epitope for HPV types 6 and 16, in various regions of the L1 structure. The L2 sequence was introduced by PCR (by replacing 13 codons) into sequences coding for L1 surface loops D-E (chideltaC-L2), E-F (chideltaA-L2), and an internal loop C-D (chideltaH-L2); into the h4 helix (chideltaF-L2); and between h4 and beta-J structural regions (chideltaE-L2). The chimeric protein product was characterized using a panel of monoclonal antibodies (MAbs) that bind to conformational and linear epitopes, as well as a polyclonal antiserum raised to the L2 epitope. All five chimeras reacted with the L2 serum. ChideltaA-L2, chideltaE-L2, and chideltaF-L2 reacted with all the L1 antibodies, chideltaC-L2 did not bind H16:V5 and H16:E70, and chideltaH-L2 did not bind any conformation-dependent MAb. The chimeric particles elicited high-titer anti-L1 immune responses in BALB/c mice. Of the five chimeras tested only chideltaH-L2 did not elicit an L2 response, while chideltaF-L2 elicited the highest L2 response. This study provides support for the use of PV particles as vectors to deliver various epitopes in a number of locations internal to the L1 protein and for the potential of using chimeric PV particles as multivalent vaccines. Moreover, it contributes to knowledge of the structure of HPV-16 L1 VLPs and their derivatives.
Project description:BackgroundA community-based randomized trial was conducted in Costa Rica to evaluate the HPV-16/18 AS04-adjuvanted vaccine (NCT00128661). The primary objective was to evaluate efficacy of the vaccine to prevent cervical intraepithelial neoplasia 2 or more severe disease (CIN2+) associated with incident HPV-16/18 cervical infections. Secondary objectives were to evaluate efficacy against CIN2+ associated with incident cervical infection by any oncogenic HPVs and to evaluate duration of protection against incident cervical infection with HPV-16/18. Vaccine safety and immunogenicity over the 4-year follow-up were also evaluated.MethodsWe randomized (3727 HPV arm; 3739 control arm), vaccinated (HPV-16/18 or Hepatitis A) and followed (median 53.8 months) 7466 healthy women aged 18-25 years. 5312 women (2635 HPV arm; 2677 control arm) were included in the according to protocol analysis for efficacy. The full cohort was evaluated for safety. Immunogenicity was considered on a subset of 354 (HPV-16) and 379 (HPV-18) women. HPV type was assessed by PCR on cervical specimens. Immunogenicity was assessed using ELISA and inhibition enzyme immunoassays. Disease outcomes were histologically confirmed. Vaccine efficacy and 95% confidence intervals (95%CI) were computed.ResultsVaccine efficacy was 89.8% (95% CI: 39.5-99.5; N=11 events total) against HPV-16/18 associated CIN2+, 59.9% (95% CI: 20.7-80.8; N=39 events total) against CIN2+ associated with non-HPV-16/18 oncogenic HPVs and 61.4% (95% CI: 29.5-79.8; N=51 events total) against CIN2+ irrespective of HPV type. The vaccine had an acceptable safety profile and induced robust and long-lasting antibody responses.ConclusionsOur findings confirm the high efficacy and immunogenicity of the HPV-16/18 vaccine against incident HPV infections and cervical disease associated with HPV-16/18 and other oncogenic HPV types. These results will serve as a benchmark to which we can compare future findings from the ongoing extended follow-up of participants in the Costa Rica trial.Trial registrationRegistered with clinicaltrials.gov: NCT00128661.
Project description:BACKGROUND:Anal cancer remains rare (incidence of about 1·5 per 100,000 women yearly), but rates are increasing in many countries. Human papillomavirus (HPV) 16 and 18 infections cause most cases of anal cancer. We assessed efficacy of an AS04-adjuvanted HPV 16 and HPV 18 vaccine against anal infection with HPV 16, HPV 18, or both (HPV 16/18). METHODS:Women from Costa Rica were registered between June 28, 2004, and Dec 21, 2005, in a randomised double-blind controlled trial that was designed to assess vaccine efficacy against persistent cervical HPV 16/18 infections and associated precancerous lesions. Eligible women were residents of Guanacaste and selected areas of Puntarenas, Costa Rica, age 18-25 years, in good general health, willing to provide informed consent, and were not pregnant or breastfeeding. Participants were randomly assigned (1:1) to receive an HPV vaccine (Cervarix, GlaxoSmithKline, Rixensart, Belgium) or a control hepatitis A vaccine (modified preparation of Havrix, GlaxoSmithKline, Rixensart, Belgium). Vaccines were administered in three 0·5 mL doses at enrolment, 1 month, and 6 months. Women, selected at the final blinded study visit 4 years after vaccination, provided anal specimens for assessment of vaccine efficacy against anal HPV 16/18 infection. Prevalence of anal HPV 16/18 infections, reported as vaccine efficacy, was the primary endpoint of the study described here. Vaccine efficacy against cervical HPV 16/18 infection in the same women at the 4-year visit was used as a comparator. Analyses were done in a restricted cohort of women who were negative for both cervical HPV 16 and HPV 18 DNA and who were HPV 16 and HPV 18 seronegative before enrolment (HPV naive), and also in the full cohort of women who provided an anal specimen. Investigators were masked to group assignment. This study is registered at ClinicalTrials.gov, number NCT00128661. FINDINGS:All women who attended the final blinded study visit and consented to anal specimen collection were included in the analysis (4210 of 6352 eligible women). In the full cohort, vaccine efficacy against prevalent HPV 16/18 infection measured one-time, 4 years post vaccination was lower at the anus (62·0%, 95% CI 47·1-73·1) compared with the cervix (76·4%, 67·0-83·5; p for interaction by anatomical site 0·031). In the restricted cohort, vaccine efficacy against anal HPV 16/18 infection was 83·6% (66·7-92·8), which was similar to vaccine efficacy against cervical HPV 16/18 infection (87·9%, 77·4-94·0). Safety issues were not addressed in the current analysis. Additional safety data will be published later in a separate article. INTERPRETATION:The AS04-adjuvanted vaccine affords strong protection against anal HPV infection, particularly among women more likely to be HPV naive at enrolment. FUNDING:National Cancer Institute with contributions from the National Institutes of Health Office of Research on Women's Health. Vaccine was provided by GlaxoSmithKline Biologicals.
Project description:Our objective was to develop a multivalent prophylactic HPV vaccine that protects against infection and disease caused by HPV16/18 (oncogenic types in existing prophylactic vaccines) plus additional oncogenic types by conducting 3 Phase II studies comparing the immunogenicity (i.e., anti-HPV6/11/16/18 geometric mean titers [GMT]) and safety of 7 vaccine candidates with the licensed quadrivalent HPV6/11/16/18 vaccine (qHPV vaccine) in young women ages 16-26. In the first study (Study 1), subjects received one of 3 dose formulations of an 8-valent HPV6/11/16/18/31/45/52/58 vaccine or qHPV vaccine (control). In Study 2, subjects received one of 3 dose formulations (termed low-, mid-, and high-dose formulations, respectively) of a 9-valent HPV6/11/16/18/31/33/45/52/58 vaccine (9vHPV vaccine) or qHPV vaccine (control). In Study 3, subjects concomitantly received qHPV vaccine plus 5-valent HPV31/33/45/52/58 or qHPV vaccine plus placebo (control). All vaccines were administered at day 1/month 2/month 6. In studies 1 and 3, anti-HPV6/11/16/18 GMTs at month 7 were non-inferior in the experimental arms compared with the control arm; however, there was a trend for lower antibody responses for all 4 HPV types. In Study 2, this immune interference was overcome with the mid- and high-dose formulations of the 9vHPV vaccine by increasing antigen and adjuvant doses. In all 3 studies, all vaccine candidates were strongly immunogenic with respect to HPV31/33/45/52/58 and were well tolerated. Based on the totality of the results, the middle dose formulation of the 9vHPV vaccine was selected for Phase III evaluation. Each 0.5mL dose contains 30μg/40μg/60μg/40μg/20μg/20μg/20μg/20μg/20μg of HPV6/11/16/18/31/33/45/52/58 virus-like particles, and 500μg of amorphous aluminum hydroxyphosphate sulfate adjuvant.ClinicalTrials.gov numbers NCT00260039, NCT00543543, and NCT00551187.