Prevention of cervical cancer: journey to develop the first human papillomavirus virus-like particle vaccine and the next generation vaccine.

In 2006, the first human papillomavirus (HPV) virus-like particle (VLP) vaccine was licensed. Gardasil(®), the quadrivalent HPV 6, 11, 16 and 18 recombinant VLP vaccine (4vHPV), developed by Merck demonstrated remarkable efficacy in prevention of important clinical pre-cursors to cervical cancer and genital warts. The vaccine was designed to protect against HPV 16 and 18 that cause ∼70% of cervical cancers and HPV 6 and 11 that cause ∼90% of genital warts. Initially, Gardasil(®) was indicated in the United States for women 9-26 years of age for the prevention of HPV 16 and 18-related cervical, vulvar and vaginal cancer, HPV 6, 11, 16 and 18-related genital intraepithelial neoplasia and the prevention of HPV 6 and 11-related genital warts. Subsequently, a bivalent HPV 16 and 18 VLP vaccine, Cervarix (2vHPV) developed by GlaxoSmithKline was licensed. Since the original licensures, the indications for Gardasil(®) have been expanded to include males and a vaccine with extended HPV coverage, Gardasil 9 (9vHPV), licensed in 2014.

Molecular Signatures of Recurrent Hepatocellular Carcinoma Secondary to Hepatitis C Virus following Liver Transplantation.

Chronic hepatitis C virus (HCV) induced hepatocellular carcinoma (HCC) is a primary indication for liver transplantation (LT). In western countries, the estimated rate of HCC recurrence following LT is between 15% and 20% and is a major cause of mortality. Currently, there is no standard method to treat patients who are at high risk for HCC recurrence. The aim of this study was to investigate the molecular signatures underlying HCC recurrence that may lead to future studies on gene regulation contributing to new therapeutic options. Two groups of patients were selected, one including patients with HCV who developed HCC recurrence (HCC-R) ≤3 years from LT and the second group including patients with HCV who did not have recurrent HCC (HCC-NR). Microarray analysis containing more than 29,000 known genes was performed on formalin-fixed-paraffin-embedded (FFPE) liver tissue from explanted livers. Gene expression profiling revealed 194 differentially regulated genes between the two groups. These genes belonged to cellular networks including cell cycle G1/S checkpoint regulators, RAN signaling, chronic myeloid leukemia signaling, molecular mechanisms of cancer, FXR/RXR activation and hepatic cholestasis. A subset of molecular signatures associated with HCC recurrence was found. The expression levels of these genes were validated by quantitative PCR analysis.

Modeling host genetic regulation of influenza pathogenesis in the collaborative cross.

Genetic variation contributes to host responses and outcomes following infection by influenza A virus or other viral infections. Yet narrow windows of disease symptoms and confounding environmental factors have made it difficult to identify polymorphic genes that contribute to differential disease outcomes in human populations. Therefore, to control for these confounding environmental variables in a system that models the levels of genetic diversity found in outbred populations such as humans, we used incipient lines of the highly genetically diverse Collaborative Cross (CC) recombinant inbred (RI) panel (the pre-CC population) to study how genetic variation impacts influenza associated disease across a genetically diverse population. A wide range of variation in influenza disease related phenotypes including virus replication, virus-induced inflammation, and weight loss was observed. Many of the disease associated phenotypes were correlated, with viral replication and virus-induced inflammation being predictors of virus-induced weight loss. Despite these correlations, pre-CC mice with unique and novel disease phenotype combinations were observed. We also identified sets of transcripts (modules) that were correlated with aspects of disease. In order to identify how host genetic polymorphisms contribute to the observed variation in disease, we conducted quantitative trait loci (QTL) mapping. We identified several QTL contributing to specific aspects of the host response including virus-induced weight loss, titer, pulmonary edema, neutrophil recruitment to the airways, and transcriptional expression. Existing whole-genome sequence data was applied to identify high priority candidate genes within QTL regions. A key host response QTL was located at the site of the known anti-influenza Mx1 gene. We sequenced the coding regions of Mx1 in the eight CC founder strains, and identified a novel Mx1 allele that showed reduced ability to inhibit viral replication, while maintaining protection from weight loss.

H5N1 virus causes significant perturbations in host proteome very early in influenza virus-infected primary human monocyte-derived macrophages.

H5N1 influenza viruses, which cause disease in humans, have unusually high pathogenicity. The temporal response of primary human monocyte-derived macrophages infected with highly pathogenic H5N1 and seasonal H1N1 influenza viruses was evaluated using mass spectrometry-based quantitative proteomic profiling. This was done in order to demonstrate significant perturbation of the host proteome upon viral infection, as early as 1 hour after infection. This early host response distinguished H5N1 infection from H1N1 infection, the latter inducing less of a response. The most pronounced effect was observed on the translational machinery, suggesting that H5N1 might gain advantage in replication by using the cell protein synthesis machinery early in the infection.

Chronic immune activation is a distinguishing feature of liver and PBMC gene signatures from HCV/HIV coinfected patients and may contribute to hepatic fibrogenesis.

Hepatitis C virus/human immunodeficiency virus (HCV/HIV) coinfected patients demonstrate accelerated progression to severe liver injury in comparison to HCV monoinfected patients, although the underlying mechanisms are unclear owing to infection of separate tissue compartments with two distinct viral pathogens. Microarray analysis of paired liver biopsy and peripheral blood mononuclear cell (PBMC) specimens from HCV/HIV coinfected and HCV monoinfected patients identified a gene expression signature associated with increased inflammation and immune activation that was present only in liver and PBMC samples from coinfected patients. We also identified in these samples liver- and PBMC-specific signatures enriched with fibrogenic/hepatic stellate activation and proinflammatory genes, respectively. Finally, Bayesian networks were constructed by assimilating these data with existing data from liver and PBMC samples from other cohorts, augmenting enrichment of biologically important pathways and further indicating that chronic immune activation in HCV/HIV coinfection may exacerbate liver disease progression in coinfected patients.

Expression quantitative trait Loci for extreme host response to influenza a in pre-collaborative cross mice.

Outbreaks of influenza occur on a yearly basis, causing a wide range of symptoms across the human population. Although evidence exists that the host response to influenza infection is influenced by genetic differences in the host, this has not been studied in a system with genetic diversity mirroring that of the human population. Here we used mice from 44 influenza-infected pre-Collaborative Cross lines determined to have extreme phenotypes with regard to the host response to influenza A virus infection. Global transcriptome profiling identified 2671 transcripts that were significantly differentially expressed between mice that showed a severe ("high") and mild ("low") response to infection. Expression quantitative trait loci mapping was performed on those transcripts that were differentially expressed because of differences in host response phenotype to identify putative regulatory regions potentially controlling their expression. Twenty-one significant expression quantitative trait loci were identified, which allowed direct examination of genes associated with regulation of host response to infection. To perform initial validation of our findings, quantitative polymerase chain reaction was performed in the infected founder strains, and we were able to confirm or partially confirm more than 70% of those tested. In addition, we explored putative causal and reactive (downstream) relationships between the significantly regulated genes and others in the high or low response groups using structural equation modeling. By using systems approaches and a genetically diverse population, we were able to develop a novel framework for identifying the underlying biological subnetworks under host genetic control during influenza virus infection.

Live attenuated herpes simplex virus 2 glycoprotein E deletion mutant as a vaccine candidate defective in neuronal spread.

A herpes simplex virus 2 (HSV-2) glycoprotein E deletion mutant (gE2-del virus) was evaluated as a replication-competent, attenuated live virus vaccine candidate. The gE2-del virus is defective in epithelial cell-to-axon spread and in anterograde transport from the neuron cell body to the axon terminus. In BALB/c and SCID mice, the gE2-del virus caused no death or disease after vaginal, intravascular, or intramuscular inoculation and was 5 orders of magnitude less virulent than wild-type virus when inoculated directly into the brain. No infectious gE2-del virus was recovered from dorsal root ganglia (DRG) after multiple routes of inoculation; however, gE2-del DNA was detected by PCR in lumbosacral DRG at a low copy number in some mice. Importantly, no recurrent vaginal shedding of gE2-del DNA was detected in immunized guinea pigs. Intramuscular immunization outperformed subcutaneous immunization in all parameters evaluated, although individual differences were not significant, and two intramuscular immunizations were more protective than one. Immunized animals had reduced vaginal disease, vaginal titers, DRG infection, recurrent genital lesions, and recurrent vaginal shedding of HSV-2 DNA; however, protection was incomplete. A combined modality immunization using live virus and HSV-2 glycoprotein C and D subunit antigens in guinea pigs did not totally eliminate recurrent lesions or recurrent vaginal shedding of HSV-2 DNA. The gE2-del virus used as an immunotherapeutic vaccine in previously HSV-2-infected guinea pigs greatly reduced the frequency of recurrent genital lesions. Therefore, the gE2-del virus is safe, other than when injected at high titer into the brain, and is efficacious as a prophylactic and immunotherapeutic vaccine.

Evidence of immune memory 8.5 years following administration of a prophylactic human papillomavirus type 16 vaccine.

BACKGROUND: The duration of protection conferred by prophylactic human papillomavirus (HPV) L1 virus-like particle vaccines is a critical determinant of their public health impact. A feature of vaccines that confer long-term immunity is their ability to induce immune memory. OBJECTIVES: We evaluated antibody responses against HPV types 6, 11, 16 and 18 following administration of the quadrivalent HPV-6/11/16/18 vaccine to women who had previously received a monovalent HPV-16 vaccine. STUDY DESIGN: As part of an extended follow-up study conducted between 2006 and 2009 in Seattle, Washington, we administered the quadrivalent HPV-6/11/16/18 vaccine to 52 women (19 vaccine and 33 placebo recipients) who had participated in a monovalent HPV-16 vaccine trial 8.5 years earlier. Serum samples were tested for anti-HPV antibodies using competitive Luminex immunoassay. RESULTS: Following administration of the first dose of the quadrivalent HPV-6/11/16/18 vaccine, the anti-HPV-16 geometric mean titer among monovalent HPV-16 vaccine recipients (GMT=5024.0 milli-Merck units per milliliter [mMU/mL]; 95% confidence interval [CI]: 2710.1, 9313.6 mMU/mL) substantially exceeded that among the placebo recipients (GMT=136.1; 95% CI: 78.5, 235.8 mMU/mL; p<0.01) and their own highest anti-HPV-16 response observed during the original trial (GMT at month 7 of the original trial=1552.7 mMU/mL; 95% CI: 1072.6, 2247.7 mMU/mL; p<0.01). CONCLUSIONS: The findings suggest that the administration of the three-dose regimen of the monovalent HPV-16 vaccine had produced memory lymphocytes, characterized by a heightened immune response following administration of the quadrivalent HPV-6/11/16/18 vaccine that effectively served as an antigen challenge.

Immunization with a vaccine combining herpes simplex virus 2 (HSV-2) glycoprotein C (gC) and gD subunits improves the protection of dorsal root ganglia in mice and reduces the frequency of recurrent vaginal shedding of HSV-2 DNA in guinea pigs compared to immunization with gD alone.

Attempts to develop a vaccine to prevent genital herpes simplex virus 2 (HSV-2) disease have been only marginally successful, suggesting that novel strategies are needed. Immunization with HSV-2 glycoprotein C (gC-2) and gD-2 was evaluated in mice and guinea pigs to determine whether adding gC-2 to a gD-2 subunit vaccine would improve protection by producing antibodies that block gC-2 immune evasion from complement. Antibodies produced by gC-2 immunization blocked the interaction between gC-2 and complement C3b, and passive transfer of gC-2 antibody protected complement-intact mice but not C3 knockout mice against HSV-2 challenge, indicating that gC-2 antibody is effective, at least in part, because it prevents HSV-2 evasion from complement. Immunization with gC-2 also produced neutralizing antibodies that were active in the absence of complement; however, the neutralizing titers were higher when complement was present, with the highest titers in animals immunized with both antigens. Animals immunized with the gC-2-plus-gD-2 combination had robust CD4+ T-cell responses to each immunogen. Multiple disease parameters were evaluated in mice and guinea pigs immunized with gC-2 alone, gD-2 alone, or both antigens. In general, gD-2 outperformed gC-2; however, the gC-2-plus-gD-2 combination outperformed gD-2 alone, particularly in protecting dorsal root ganglia in mice and reducing recurrent vaginal shedding of HSV-2 DNA in guinea pigs. Therefore, the gC-2 subunit antigen enhances a gD-2 subunit vaccine by stimulating a CD4+ T-cell response, by producing neutralizing antibodies that are effective in the absence and presence of complement, and by blocking immune evasion domains that inhibit complement activation.

The humoral response to Gardasil over four years as defined by total IgG and competitive Luminex immunoassay.

Safe and effective vaccines against anogenital human papillomaviruses (HPV) are now available. These vaccines, composed of virus-like particles (VLPs) made from the L1 major capsid protein of specific HPV types, induce a polyclonal antibody response directed against specific conformational and linear epitopes displayed on the VLP. Numerous studies indicated the importance of neutralizing antibodies in protection from infection. However, our understanding of the antibody responses to these vaccines is not complete, and there is no established immune correlate of protection nor antibody threshold that correlates with protection against HPV infection or disease. In the current study, antibody responses of young women to Gardasil®, the quadrivalent HPV 6, 11, 16 and 18 L1 VLP vaccine (qHPV), were assessed through 48 months (M) in total IgG and competitive Luminex immunoassays (total IgG LIA and cLIA). The total IgG LIA was developed as a research assay to evaluate preclinical multivalent HPV VLP vaccine formulations. The cLIA simultaneously evaluates the antibody response to a unique conformational, neutralizing epitope on each of the four HPV types present in the quadrivalent vaccine; HPV 6, 11, 16 and 18. The same sera from women vaccinated with the qHPV vaccine were tested in both the total IgG LIA and the cLIA assays. The proportion of vaccinated women achieving seropositivity and the anti-HPV VLP total IgG and cLIA geometric mean titers (GMTs) were summarized at M7, M24, M48 based on the serostatus cut-points defined for each immunoassay. Overall, greater than 99% of subjects seroconverted to all four vaccine types in both assays; GMTs peaked at M7. For all four HPV types, regardless of the immunoassay used, the most significant decline in GMTs was observed between M7 and M24. By M24, the antibody titers had reached a plateau and minimal declines in antibody titers were observed between M24 and M48 for all four HPV types in both immunoassays. Testing the same sera, seropositivity for M48 HPV18 remained high (96.7%) in the total IgG LIA, but was 64.8% in the cLIA. The current study illustrates potential important differences in serologic assays utilized in the clinical trials of the two currently available HPV VLP vaccines (quadrivalent and bivalent). Differences in seropositivity status are attributed to the measurement parameters and sensitivity of the individual immunoassays and do not indicate reduced anti-HPV18 protective antibodies.

Comparison of real-time multiplex human papillomavirus (HPV) PCR assays with the linear array HPV genotyping PCR assay and influence of DNA extraction method on HPV detection.

Real-time human papillomavirus (HPV) type-specific multiplex PCR assays were developed to detect HPV DNA in specimens collected for the efficacy determination of the quadrivalent HPV (type 6, 11, 16, and 18) L1 virus-like particle (VLP) vaccine (Gardasil). We evaluated the concordance between type-specific multiplex HPV PCR and the widely used, commercially available Roche Linear Array genotyping PCR assay. Female genital swab specimens were tested for the presence of L1, E6, and E7 sequences of HPV type 6 (HPV6), HPV11, HPV16, HPV18, HPV31, HPV45, HPV52, and HPV58 and E6 and E7 sequences of HPV33, HPV35, HPV39, HPV51, HPV56, and HPV59 in type- and gene-specific real-time multiplex PCR assays. Specimens were also tested for the presence of L1 sequences using two versions of the Roche Linear Array genotyping assay. Measures of concordance of a modified version of the Linear Array and the standard Linear Array PCR assay were evaluated. With specimen DNA extraction using the Qiagen Spin blood kit held as the constant, multiplex PCR assays detect more HPV-positive specimens for the 14 HPV types common to both than either version of the Linear Array HPV genotyping assay. Type-specific agreements between the assays were good, at least 0.838, but were often driven by negative agreement in HPV types with low prevalence, as evidenced by reduced proportions of positive agreement. Overall HPV status agreements ranged from 0.615 for multiplex PCR and standard Linear Array to 0.881 for multiplex PCR and modified Linear Array. An alternate DNA extraction technique, that used by the Qiagen MinElute kit, impacted subsequent HPV detection in both the multiplex PCR and Linear Array assays.

Comparison of real-time multiplex human papillomavirus (HPV) PCR assays with INNO-LiPA HPV genotyping extra assay.

Real-time type-specific multiplex human papillomavirus (HPV) PCR assays were developed to detect HPV DNA in samples collected for the efficacy determination of the quadrivalent HPV (type 6, 11, 16, and 18) L1 virus-like particle (VLP) vaccine (Gardasil). Additional multiplex (L1, E6, and E7 open reading frame [ORF]) or duplex (E6 and E7 ORF) HPV PCR assays were developed to detect high-risk HPV types, including HPV type 31 (HPV31), HPV33, HPV35, HPV39, HPV45, HPV51, HPV52, HPV56, HPV58, and HPV59. Here, we evaluated clinical specimen concordance and compared the limits of detection (LODs) between multiplex HPV PCR assays and the INNO-LiPA HPV Genotyping Extra assay, which detects 28 types, for the 14 HPV types common to both of these methods. Overall HPV detection agreement rates were >90% for swabs and >95% for thin sections. Statistically significant differences in detection were observed for HPV6, HPV16, HPV18, HPV35, HPV39, HPV45, HPV56, HPV58, and HPV59 in swabs and for HPV45, HPV58, and HPV59 in thin sections. Where P was <0.05, discordance was due to detection of more HPV-positive samples by the multiplex HPV PCR assays. LODs were similar for eight HPV types, significantly lower in multiplex assays for five HPV types, and lower in INNO-LiPA for HPV6 only. LODs were under 50 copies for all HPV types, with the exception of HPV39, HPV58, and HPV59 in the INNO-LiPA assay. The overall percent agreement for detection of 14 HPV types between the type-specific multiplex HPV PCR and INNO-LiPA genotyping assays was good. The differences in positive sample detection favored multiplex HPV PCR, suggesting increased sensitivity of HPV DNA detection by type-specific multiplex HPV PCR assays.

Four year efficacy of prophylactic human papillomavirus quadrivalent vaccine against low grade cervical, vulvar, and vaginal intraepithelial neoplasia and anogenital warts: randomised controlled trial.

OBJECTIVES: To evaluate the prophylactic efficacy of the human papillomavirus (HPV) quadrivalent vaccine in preventing low grade cervical, vulvar, and vaginal intraepithelial neoplasias and anogenital warts (condyloma acuminata). DESIGN: Data from two international, double blind, placebo controlled, randomised efficacy trials of quadrivalent HPV vaccine (protocol 013 (FUTURE I) and protocol 015 (FUTURE II)). The trials were to be 4 years in length, and the results reported are from final study data of 42 months' follow-up. SETTING: Primary care centres and university or hospital associated health centres in 24 countries and territories around the world. PARTICIPANTS: 17 622 women aged 16-26 years enrolled between December 2001 and May 2003. Major exclusion criteria were lifetime number of sexual partners (>4), history of abnormal cervical smear test results, and pregnancy. INTERVENTION: Three doses of quadrivalent HPV vaccine (for serotypes 6, 11, 16, and 18) or placebo at day 1, month 2, and month 6. MAIN OUTCOME MEASURES: Vaccine efficacy against cervical, vulvar, and vaginal intraepithelial neoplasia grade I and condyloma in a per protocol susceptible population that included subjects who received all three vaccine doses, tested negative for the relevant vaccine HPV types at day 1 and remained negative through month 7, and had no major protocol violations. Intention to treat, generally HPV naive, and unrestricted susceptible populations were also studied. RESULTS: In the per protocol susceptible population, vaccine efficacy against lesions related to the HPV types in the vaccine was 96% for cervical intraepithelial neoplasia grade I (95% confidence interval 91% to 98%), 100% for both vulvar and vaginal intraepithelial neoplasia grade I (95% CIs 74% to 100%, 64% to 100% respectively), and 99% for condyloma (96% to 100%). Vaccine efficacy against any lesion (regardless of HPV type) in the generally naive population was 30% (17% to 41%), 75% (22% to 94%), and 48% (10% to 71%) for cervical, vulvar, and vaginal intraepithelial neoplasia grade I, respectively, and 83% (74% to 89%) for condyloma. CONCLUSIONS: Quadrivalent HPV vaccine provided sustained protection against low grade lesions attributable to vaccine HPV types (6, 11, 16, and 18) and a substantial reduction in the burden of these diseases through 42 months of follow-up. TRIAL REGISTRATIONS: NCT00092521 and NCT00092534.

Impact of human papillomavirus (HPV)-6/11/16/18 vaccine on all HPV-associated genital diseases in young women.

BACKGROUND: The impact of the prophylactic vaccine against human papillomavirus (HPV) types 6, 11, 16, and 18 (HPV6/11/16/18) on all HPV-associated genital disease was investigated in a population that approximates sexually naive women in that they were "negative to 14 HPV types" and in a mixed population of HPV-exposed and -unexposed women (intention-to-treat group). METHODS: This analysis studied 17 622 women aged 15-26 years who were enrolled in one of two randomized, placebo-controlled, efficacy trials for the HPV6/11/16/18 vaccine (first patient on December 28, 2001, and studies completed July 31, 2007). Vaccine or placebo was given at day 1, month 2, and month 6. All women underwent cervicovaginal sampling and Papanicolaou (Pap) testing at day 1 and every 6-12 months thereafter. Outcomes were any cervical intraepithelial neoplasia; any external anogenital and vaginal lesions; Pap test abnormalities; and procedures such as colposcopy and definitive therapy. Absolute rates are expressed as women with endpoint per 100 person-years at risk. RESULTS: The average follow-up was 3.6 years (maximum of 4.9 years). In the population that was negative to 14 HPV types, vaccination was up to 100% effective in reducing the risk of HPV16/18-related high-grade cervical, vulvar, and vaginal lesions and of HPV6/11-related genital warts. In the intention-to-treat group, vaccination also statistically significantly reduced the risk of any high-grade cervical lesions (19.0% reduction; rate vaccine = 1.43, rate placebo = 1.76, difference = 0.33, 95% confidence interval [CI] = 0.13 to 0.54), vulvar and vaginal lesions (50.7% reduction; rate vaccine = 0.10, rate placebo = 0.20, difference = 0.10, 95% CI = 0.04 to 0.16), genital warts (62.0% reduction; rate vaccine = 0.44, rate placebo = 1.17, difference = 0.72, 95% CI = 0.58 to 0.87), Pap abnormalities (11.3% reduction; rate vaccine = 10.36, rate placebo = 11.68, difference = 1.32, 95% CI = 0.74 to 1.90), and cervical definitive therapy (23.0% reduction; rate vaccine = 1.97, rate placebo = 2.56, difference = 0.59, 95% CI = 0.35 to 0.83), irrespective of causal HPV type. CONCLUSIONS: High-coverage HPV vaccination programs among adolescents and young women may result in a rapid reduction of genital warts, cervical cytological abnormalities, and diagnostic and therapeutic procedures. In the longer term, substantial reductions in the rates of cervical, vulvar, and vaginal cancers may follow.

Longer term efficacy of a prophylactic monovalent human papillomavirus type 16 vaccine.

We conducted an extended follow-up study (March 2006-May 2008) to assess the longer term efficacy of a prophylactic monovalent human papillomavirus (HPV) type 16 L1 virus-like particle vaccine in women (n=290) who had enrolled in a randomized controlled trial of this vaccine (October 1998-November 1999) in Seattle and remained HPV-16 DNA negative during the course of that trial. During the extended follow-up period, in the per-protocol susceptible population, none of the vaccine recipients was found to be infected with HPV-16 or developed HPV-16-related cervical lesions; among placebo recipients, 6 women were found to be infected with HPV-16 (vaccine efficacy [VE]=100%; 95% confidence interval [CI]: 29-100%) and 3 women developed HPV-16-related cervical lesions (VE=100%; 95% CI: <0-100%). Approximately 86% of vaccine recipients remained HPV-16 competitive Luminex immunoassay seropositive at an average of 8.5 years of follow-up. During the combined original trial and extended follow-up period, in the intention-to-treat population, 20 and 22 women developed any cervical lesion regardless of HPV type among the vaccine and placebo recipients, respectively (VE=15%; 95% CI: <0-56%). The results suggest that this monovalent HPV-16 vaccine remains efficacious through 8.5 years after its administration.

Importance of specimen type in detecting human papillomavirus DNA from the female genital tract.

HPV testing is a valuable tool in cervical cancer screening and efficacy assessment of HPV vaccines. Concordance of specimens from three sites for detection of HPV DNA in the female genital tract was evaluated. At a single visit, the following specimens were collected: an endo-ecto-cervical swab (EEC), labial/vulvar/perineal/perianal swab (LVPP) and cervicovaginal lavage (CVL). Specimens were evaluated with HPV6, HPV11, HPV16, and HPV18 type- and gene-specific PCR assays. Of the 898 women evaluated at baseline, 232 were HPV PCR positive in at least one specimen. Of these, for HPV6, HPV11, HPV16, and HPV18, respectively, throughout: (a) 70.4%, 40.0%, 65.3%, and 64.1% tested three-site positive; (b) 13.6%, 30.0%, 19.7%, and 18.8% tested two-site positive; and (c) 16.4%, 30.0%, 15.0%, and 17.2% tested single-site positive. For patients who tested single-site positive for HPV6, HPV11, HPV16, or HPV18, respectively, the specimen was: LVPP in 92.3%, 33.3%, 68.2%, and 72.7%; EEC in 0.0%, 33.3%, 18.2%, and 9.1%; and CVL in 7.7%, 33.3%, 13.6%, and 18.2%. Combining results of swab specimens together increases detection of HPV6, HPV11, HPV16, and HPV 18, respectively, to 98.7%, 90.0%, 97.9%, and 96.9%. HPV DNA is detectable from all three sites using type-specific PCR assays; most women who tested positive for a given HPV type were positive for that type in all three specimens.

Study comparing human papillomavirus (HPV) real-time multiplex PCR and Hybrid Capture II INNO-LiPA v2 HPV genotyping PCR assays.

Human papillomavirus (HPV) DNA genotyping is an essential test to establish efficacy in HPV vaccine clinical trials and HPV prevalence in natural history studies. A number of HPV DNA genotyping methods have been cited in the literature, but the comparability of the outcomes from the different methods has not been well characterized. Clinically, cytology is used to establish possible HPV infection. We evaluated the sensitivity and specificity of HPV multiplex PCR assays compared to those of the testing scheme of the Hybrid Capture II (HCII) assay followed by an HPV PCR/line hybridization assay (HCII-LiPA v2). SurePath residual samples were split into two aliquots. One aliquot was subjected to HCII testing followed by DNA extraction and LiPA v2 genotyping. The second aliquot was shipped to a second laboratory, where DNA was extracted and HPV multiplex PCR testing was performed. Comparisons were evaluated for 15 HPV types common in both assays. A slightly higher proportion of samples tested positive by the HPV multiplex PCR than by the HCII-LiPA v2 assay. The sensitivities of the multiplex PCR assay relative to those of the HCII-LiPA v2 assay for HPV types 6, 11, 16, and 18, for example, were 0.806, 0.646, 0.920, and 0.860, respectively; the specificities were 0.986, 0.998, 0.960, and 0.986, respectively. The overall comparability of detection of the 15 HPV types was quite high. Analyses of DNA genotype testing compared to cytology results demonstrated a significant discordance between cytology-negative (normal) and HPV DNA-positive results. This demonstrates the challenges of cytological diagnosis and the possibility that a significant number of HPV-infected cells may appear cytologically normal.

Genetic variation in the vitamin C transporter, SLC23A2, modifies the risk of HPV16-associated head and neck cancer.

Human papillomavirus (HPV) type 16 infection is an etiologic factor in a subset of head and neck squamous cell carcinomas (HNSCC). It is unknown if host genetic susceptibility modifies the HPV16-HNSCC association. DNA samples collected as part of a Boston area case-control study of HNSCC were genotyped for single-nucleotide polymorphisms (SNPs) from the National Cancer Institute's SNP500Cancer database. Analysis of demographic, phenotypic and genotypic data for 319 HNSCC cases and 495 frequency-matched controls was performed using unconditional logistic regression. All reported P-values are two sided. We identified a polymorphism in the sodium-dependent vitamin C transporter SLC23A2 that modifies the risk of HNSCC associated with HPV16 infection. Among those with a wild-type allele at SLC23A2, the risk of HNSCC associated with HPV16-positive serology was 5.0 (95% confidence interval (CI) = 3.2-7.8). However, among those with a homozygous variant genotype, the risk of HNSCC associated with HPV16 was attenuated [odds ratio (OR) = 2.8; 95% CI = 1.2-6.2]. Further, when we tested whether genotype modified the interaction between citrus exposure, HPV16, and HNSCC, we found a dramatically increased risk of HNSCC for those with a wild-type SLC23A2 allele, HPV16-positive serology and high citrus intake (OR = 7.4; 95% CI = 3.6-15.1). These results suggest that SLC23A2 genetic variation alters HPV16-associated HNSCC while also highlighting the important role of citrus exposure in this disease.

Evolution of type-specific immunoassays to evaluate the functional immune response to Gardasil: a vaccine for human papillomavirus types 16, 18, 6 and 11.

Epidemiological studies and clinical trials of vaccines depend on the accurate measurement of antibodies within the polyclonal response to infection or vaccination. The assay currently used to measure the antibody response to vaccination with GARDASIL [Quadrivalent Human Papillomavirus (Types 6, 11, 16, 18) Recombinant Vaccine]--a quadrivalent vaccine used against human papillomavirus (HPV) types 6, 11, 16, and 18--is a competitive Luminex assay (cLIA) that uses multiplex technology to detect type-specific neutralizing antibodies against all four HPV types in a single serum sample. Here we describe how the cLIA was developed, as well as how the monoclonal antibodies (mAbs), used as competitors in the assay, were characterized. An enzyme-linked immunosorbent assay (ELISA) was used to screen eight previously-identified mAbs for their ability to bind to HPV virus-like particles (VLPs) in a type-specific and conformation-dependent manner. Four of these mAbs, H6.M48, K11.B2, H16.V5, and H18.J4, met our specifications and were shown to have the potential to neutralize HPV infection in hemagglutination inhibition and pseudovirus neutralization assays. The competitive immunoassay format was able to distinguish type-specific antibodies in the sera of nonhuman primates vaccinated with HPV VLPs, whereas a traditional direct-bind ELISA could not. In addition, the serum antibodies measured by the competitive assay are known to be neutralizing, whereas the ELISA does not distinguish neutralizing and nonneutralizing antibodies in a serum sample. By detecting antibodies to neutralizing epitopes, the competitive assay both demonstrates sero-conversion and provides a potential functional link between sero-conversion and protective immunity in response to vaccination with GARDASIL.

Antibodies from women immunized with Gardasil cross-neutralize HPV 45 pseudovirions.

Human papillomavirus (HPV) types 6, 11, 16 and 18 L1 virus-like particles (VLPs) have been used to generate the prophylactic quadrivalent vaccine, Gardasil. There is a high degree of L1 homology between HPV types and it is likely that there is a substantial degree of surface exposed viral epitope similarity. An investigation of vaccine-induced antibody binding and neutralization was undertaken focusing on A7 species members, HPV 18 and 45. Polyclonal sera from Gardasil recipients and from HPV 18 L1 VLP recipients were evaluated. Vaccine-induced antibodies were found to cross-neutralize HPV 45 pseudovirions (PsV) in vitro. Examination of a panel of monoclonal antibodies made against L1 VLPs revealed the presence of conformational, neutralizing epitopes on the surface of VLPs that may be shared between HPV 18 and HPV 45. These data demonstrate that Gardasil(r) immunization induces antibodies capable of neutralizing HPV 18 PsV and HPV 45 PsV in vitro.