HPV16 antibodies as risk factors for oropharyngeal cancer and their association with tumor HPV and smoking status

Phyllanthus emblica fruits: a polyphenol-rich fruit with potential benefits for oral management

The fruit of Phyllanthus emblica Linn., which mainly grows in tropical and subtropical regions, is well-known for its medicine and food homology properties. It has a distinctive flavor, great nutritional content, and potent antioxidant, anti-inflammatory, anti-cancer and immunoregulatory effects. According to an increasing amount of scientific and clinical evidence, this fruit shows significant potential for application and development in the field of oral health management. Through the supplementation of vitamins, superoxide dismutase (SOD) and other nutrients reduce virulence expression of various oral pathogens, prevent tissue and mucosal damage caused by oxidative stress, etc. Phyllanthus emblica fruit can promote saliva secretion, regulate the balance of the oral microecology, prevent and treat oral cancer early, promote alveolar bone remodeling and aid mucosal wound healing. Thus, it plays a specific role in the prevention and treatment of common oral disorders, producing surprising results. For instance, enhancing the effectiveness of scaling and root planing in the treatment of periodontitis, relieving mucosal inflammation caused by radiotherapy for oral cancer, and regulating the blood glucose metabolism to alleviate oral discomfort. Herein, we systematically review the latest research on the use of Phyllanthus emblica fruit in the management of oral health and examine the challenges and future research directions based on its chemical composition and characteristics.

The Tumor-Specific Immune Landscape in HPV+ Head and Neck Cancer

Human papillomaviruses (HPVs) are the causative agent of several anogenital cancers as well as head and neck cancers, with HPV+ head and neck squamous cell carcinoma (HNSCC) becoming a rapidly growing public health issue in the Western world. Due its viral etiology and potentially its subanatomical location, HPV+ HNSCC exhibits an immune microenvironment which is more inflamed and thus distinct from HPV-negative HNSCC. Notably, the antigenic landscape in most HPV+ HNSCC tumors extends beyond the classical HPV oncoproteins E6/7 and is extensively targeted by both the humoral and cellular arms of the adaptive immune system. Here, we provide a comprehensive overview of HPV-specific immune responses in patients with HPV+ HNSCC. We highlight the localization, antigen specificity, and differentiation states of humoral and cellular immune responses, and discuss their similarities and differences. Finally, we review currently pursued immunotherapeutic treatment modalities that attempt to harness HPV-specific immune responses for improving clinical outcomes in patients with HPV+ HNSCC.

Efficacy and Synergy with Cisplatin of an Adenovirus Vectored Therapeutic E1E2E6E7 Vaccine against HPV Genome-Positive C3 Cancers in Mice

Human papillomavirus (HPV) infections are the main cause of cervical and oropharyngeal cancers. As prophylactic vaccines have no curative effect, an efficient therapy would be highly desired. Most therapeutic vaccine candidates target only a small subset of HPV regulatory proteins, namely, E6 and E7, and are therefore restricted in the breadth of their immune response. However, research has suggested E1 and E2 as promising targets to fight HPV+ cancer. Here, we report the design of adenoviral vectors efficiently expressing HPV16 E1 and E2 in addition to transformation-deficient E6 and E7. Vaccination elicited vigorous CD4+ and CD8+ T-cell responses against all encoded HPV16 proteins in outbred mice and against E1 and E7 in C57BL/6 mice. Therapeutic vaccination of C3 tumor-bearing mice led to significantly reduced tumor growth and enhanced survival for both small and established tumors. Tumor biopsies revealed increased numbers of tumor-infiltrating CD8+ T cells in treated mice. Cisplatin enhanced the effect of therapeutic vaccination, accompanied by enhanced infiltration of dendritic cells into the tumor. CD8+ T cells were identified as effector cells in T-cell depletion assays, seemingly under regulation by FoxP3+CD4+ regulatory T cells. Finally, therapeutic vaccination with Ad-Ii-E1E2E6E7 exhibited significantly enhanced survival compared with vaccination with two peptides each harboring a known E6/E7 epitope. We hypothesize that this difference could be due to the induction of additional T-cell responses against E1. These results support the use of this novel vaccine candidate targeting an extended set of antigens (Ad-Ii-E1E2E6E7), in combination with cisplatin, as an advanced strategy to combat HPV+ cancers.

Does human papillomavirus modify the risk of oropharyngeal cancer related to smoking and alcohol drinking? A systematic review and meta‐analysis

Objective

To synthesize evidence for interactions of traditional oropharyngeal squamous cell carcinoma (OPSCC) risk factors—tobacco smoking and alcohol drinking—with human papillomavirus (HPV).

Data Sources

MEDLINE, Embase, Cochrane Database of Systematic Reviews, ProQuest, and Global Health were searched with no restrictions on language or publication date.

Methods

All case–control studies assessing interactions between these factors in OPSCC were considered. Quality was assessed using the Newcastle‐Ottawa Scale for case–control studies. The main outcome was the OR for developing OPSCC for the following interactions: (1) HPV and smoking, (2) HPV and alcohol drinking, and (3) HPV, alcohol drinking, and smoking. Interactions were assessed from stratified analysis (by HPV status) and/or joint effect analysis (synergy index and multiplicative index).

Results

The search provided 3084 relevant studies, of which 9 were included. In the stratified analysis, the OR of developing OPSCC among smokers with HPV was less than that among smokers without HPV. A similar pattern was observed for alcohol drinking. This effect persisted among smokers and heavy alcohol drinkers with HPV compared with those without HPV. Joint effect analysis on the additive scale showed sub‐additive antagonistic interactions between HPV and smoking, and between HPV and alcohol. On the multiplicative scale, sub‐multiplicative interactions were found between HPV and smoking, and HPV and alcohol.

Conclusions

This meta‐analysis suggests a negative directed interaction of HPV and smoking; and HPV and heavy alcohol drinking in the development of primary OPSCC on stratified analysis and joint effect analysis.

Level of Evidence

3A.

Novel Antigenic Targets of HPV Therapeutic Vaccines

Human papillomavirus (HPV) infection is the cause of the majority of cervical cancers and head and neck cancers worldwide. Although prophylactic vaccines and cervical cancer screening programs have shown efficacy in preventing HPV-associated cervical cancer, cervical cancer is still a major cause of morbidity and mortality, especially in third world countries. Furthermore, head and neck cancer cases caused by HPV infection and associated mortality are increasing. The need for better therapy is clear, and therapeutic vaccination generating cytotoxic T cells against HPV proteins is a promising strategy. This review covers the current scene of HPV therapeutic vaccines in clinical development and discusses relevant considerations for the design of future HPV therapeutic vaccines and clinical trials, such as HPV protein expression patterns, immunogenicity, and exhaustion in relation to the different stages and types of HPV-associated lesions and cancers. Ultimately, while the majority of the HPV therapeutic vaccines currently in clinical testing target the two HPV oncoproteins E6 and E7, we suggest that there is a need to include more HPV antigens in future HPV therapeutic vaccines to increase efficacy and find that especially E1 and E2 could be promising novel targets.

Screening for HPV-related oropharyngeal, anal, and penile cancers in middle-aged men: Initial report from the HOUSTON clinical trial

BACKGROUND

The Human papillomavirus (HPV)-related Oropharyngeal and Uncommon Cancers Screening Trial of Men (HOUSTON) was designed to determine the prevalence of IgG antibodies to HPV type 16 E proteins (HPV16EAbs), to screen for persistence of HPV and/or detect HPV-related premalignancies and cancers, and to assess acceptance of screening among middle-aged men.

METHODS

HOUSTON consists of a cross-sectional study and a longitudinal cohort study of men aged 50-64 years. Serologic HPV16EAb status and oral rinse HPV16 status were determined. All HPV16EAb-positive (HPV16EAb+) men and a matched cohort of HPV16EAb-negative (HPV16EAb-) men as well as all oral rinse HPV16-positive (HPV16+) men were included in the longitudinal study (blinded to their results) and underwent oropharyngeal screening every 6 months as well as one-time anal and penile screening.

RESULTS

Of 553 men enrolled in the cross-sectional study, six (1.1%) were HPV16EAb+ (two were also oral rinse HPV16+), and 41 (7.4%) were HPV16EAb- but oral rinse HPV16+. These 47 men, along with five matched controls, were invited to participate in the longitudinal study, and 42 (81%) agreed and completed baseline in-person screening, with 93% and 90% completeing 6-month and 12-month follow-up visits. One HPV16EAb+ (also oral rinse HPV16+) man, who declined participation in the longitudinal study, presented 4 months after enrollment with an early-stage HPV16-related pharyngeal cancer. Additionally, one HPV16EAb+ (oral rinse HPV16-) man and two oral rinse HPV16+ (HPV16EAb-) men were diagnosed with oncogenic HPV-associated anal dysplasia.

CONCLUSIONS

This biomarker panel deserves further prospective study to explore potential utility for HPV-related cancer screening among men.

Sensitivity and Specificity of Human Papillomavirus (HPV) 16 Early Antigen Serology for HPV-Driven Oropharyngeal Cancer: A Systematic Literature Review and Meta-Analysis

Simple Summary

Serum antibodies against human papillomavirus 16 (HPV16) proteins are associated with HPV-driven oropharyngeal cancer (HPV-OPC). The HPV status of OPC cases is clinically relevant because patients with HPV-OPC show improved survival and treatment response compared to tobacco- or alcohol-induced OPC. In clinical settings, molecular HPV tumor status is usually determined by tissue-based methods detecting molecular markers, such as viral nucleic acids or p16 overexpression. Antibodies against HPV16 in peripheral blood were shown to be very accurate in determining the molecular HPV tumor status in multiple studies. In this work, we reviewed and summarized the available literature on the performance of HPV16 serology for E2, E6 and E7 antibodies to determine molecular HPV tumor status in OPC cases in comparison with tissue-based reference methods. We calculated summary estimates across different studies for sensitivity and specificity, and we investigated factors influencing test performance.

Abstract

Antibodies against HPV16 early proteins have been shown to be promising biomarkers for the identification of HPV-driven oropharyngeal cancer (HPV-OPC) among OPC cases in multiple studies. A systematic literature search was performed to identify original research articles comparing HPV early antigen serology with established reference methods to determine molecular HPV tumor status. Random-effects models were used to calculate summary estimates for sensitivity and specificity of HPV16 E2, E6 and E7 serology for HPV-OPC. Subgroup analyses were performed to explore heterogeneity across studies and describe variables associated with test performance. We identified n = 23 studies meeting all eligibility criteria and included these in the meta-analysis. E6 serology showed the best performance with pooled sensitivity and specificity estimates of 83.1% (95% confidence interval (CI) 72.5–90.2%) and 94.6% (95% CI 89.0–97.4%), respectively, while E2 and E7 serological assays were highly specific (E2: 92.5% (95% CI 79.1–97.6%); E7: 88.5% (95% CI 77.9–94.4%)) but moderately sensitive (E2: 67.8% (95% CI 58.9–75.6%); E7: 67.0% (95% CI 63.2–70.6%)). Subgroup analyses revealed increased pooled sensitivity for bacterially (89.9% (95% CI 84.5–93.6%)) vs. in vitro expressed E6 antigen (55.3% (95% CI 41.0–68.7%)), while both showed high specificity (95.2% (95% CI 93.0–96.7%) and 91.1% (95% CI 46.6–99.2%), respectively). Pooled specificity estimates for HPV16 E2, E6 and E7 serology were significantly lower in studies utilizing HPV DNA PCR as the only molecular reference method compared to those using a combination of any two reference methods (HPV DNA, RNA, in situ hybridization (ISH), p16 immunohistochemistry (IHC)), or histopathological reference methods (ISH or p16 IHC) as stand-alone marker. In conclusion, HPV16 E6 seropositivity is a highly sensitive and specific biomarker for HPV-OPC. However, its performance differs between serological assays and depends on molecular reference methods.

Investigating the association between serum human papillomavirus type 16 E7 antibodies and risk of head and neck cancer

Human papillomavirus (HPV) is recognized as a major cause of oropharyngeal cancer (OPC) in Western countries. Less is known regarding its contribution to the OPC occurring in Asia. The current study aimed to investigate the association between antibody responses to HPV16 E7 and head and neck cancer (HNC) risk in a hospital‐based case–control study conducted in Taiwan with 693 HNC cases and 1,035 controls. A positive association was observed between seropositivity to HPV16 E7 and OPC risk, whereas no significant association was found in the non‐OPC cases. The increased OPC risk associated with seropositivity to HPV16 E7 was more significant among nonbetel quid or noncigarette users. Seropositivity to HPV16 E7 showed moderate agreement with P16 expression in OPC. OPC patients that were seropositive to HPV16 E7 or p16 positive were more highly educated and less likely to use alcohol, betel quids, and cigarettes compared to HPV16 E7 seronegative or p16 negative OPC patients. Furthermore, patients with p16 positive OPC were more likely to be women compared to patients with p16 negative OPC, likely owing to the low prevalence of alcohol, betel quid, and cigarette users among women. Overall, this study suggested that similar to Western countries, HPV may also be an important risk factor of OPC in Taiwan. With the declining consumption of betel quids and cigarettes in Taiwan, a higher percentage of OPC cases in Taiwan will be attributed to HPV in the future. Public health measures, including HPV vaccination, need to be implemented to prevent the occurrence of HPV‐positive OPC.

The current study found a a positive association between seropositivity to HPV16 E7 and oropharyngeal cancer risk. This study suggested that similar to Western countries, HPV may also be an important risk factor of OPC in Taiwan.

Blood-based biomarkers of human papillomavirus-associated cancers: A systematic review and meta-analysis

BACKGROUND

Despite the significant societal burden of human papillomavirus (HPV)-associated cancers, clinical screening interventions for HPV-associated noncervical cancers are not available. Blood-based biomarkers may help close this gap in care.

METHODS

Five databases were searched, 5687 articles were identified, and 3631 unique candidate titles and abstracts were independently reviewed by 2 authors; 702 articles underwent a full-text review. Eligibility criteria included the assessment of a blood-based biomarker within a cohort or case-control study.

RESULTS

One hundred thirty-seven studies were included. Among all biomarkers assessed, HPV-16 E seropositivity and circulating HPV DNA were most significantly correlated with HPV-associated cancers in comparison with cancer-free controls. In most scenarios, HPV-16 E6 seropositivity varied nonsignificantly according to tumor type, specimen collection timing, and anatomic site (crude odds ratio [cOR] for p16+ or HPV+ oropharyngeal cancer [OPC], 133.10; 95% confidence interval [CI], 59.40-298.21; cOR for HPV-unspecified OPC, 25.41; 95% CI, 8.71-74.06; cOR for prediagnostic HPV-unspecified OPC, 59.00; 95% CI, 15.39-226.25; cOR for HPV-unspecified cervical cancer, 12.05; 95% CI, 3.23-44.97; cOR for HPV-unspecified anal cancer, 73.60; 95% CI, 19.68-275.33; cOR for HPV-unspecified penile cancer, 16.25; 95% CI, 2.83-93.48). Circulating HPV-16 DNA was a valid biomarker for cervical cancer (cOR, 15.72; 95% CI, 3.41-72.57). In 3 cervical cancer case-control studies, cases exhibited unique microRNA expression profiles in comparison with controls. Other assessed biomarker candidates were not valid.

CONCLUSIONS

HPV-16 E6 antibodies and circulating HPV-16 DNA are the most robustly analyzed and most promising blood-based biomarkers for HPV-associated cancers to date. Comparative validity analyses are warranted. Variations in tumor type-specific, high-risk HPV DNA prevalence according to anatomic site and world region highlight the need for biomarkers targeting more high-risk HPV types. Further investigation of blood-based microRNA expression profiling appears indicated.

[Individual-specific symptoms of malignant neoplasms of the oropharynx occurring in otolaryngologist's practice]

According to statistical data given in the article the incidence of oropharyngeal cancer increases, despite the ease of access to the maxillofacial area and the possibility to make visual and manual examination of this site. It should be stressed that locally advanced oropharyngeal cancer of the III-IV stages was the first diagnosis in 82.9% of patients. It may be due to low level suspicion of primary care physicians. The paper considers risk factors for development of oropharyngeal cancer and presents the list of compulsory diagnostic tests. The authors suggest that recommended diagnostic algorithm will be helpful to a timely detection of precancer and cancer abnormalities in the oropharynx in order to minimize the time and to define the optimal scheduling of examination of a patient in specialized health care centers for early detection of cancer.

Immunodiagnosis and Immunotherapeutics Based on Human Papillomavirus for HPV-Induced Cancers

Infection with human papillomavirus (HPV) is one of the main causes of malignant neoplasms, especially cervical, anogenital, and oropharyngeal cancers. Although we have developed preventive vaccines that can protect from HPV infection, there are still many new cases of HPV-related cancers worldwide. Early diagnosis and therapy are therefore important for the treatment of these diseases. As HPVs are the major contributors to these cancers, it is reasonable to develop reagents, kits, or devices to detect and eliminate HPVs for early diagnosis and therapeutics. Immunological methods are precise strategies that are promising for the accurate detection and blockade of HPVs. During the last decades, the mechanism of how HPVs induce neoplasms has been extensively elucidated, and several oncogenic HPV early proteins, including E5, E6, and E7, have been shown to be positively related to the oncogenesis and malignancy of HPV-induced cancers. These oncoproteins are promising biomarkers for diagnosis and as targets for the therapeutics of HPV-related cancers. Importantly, many specific monoclonal antibodies (mAbs), or newly designed antibody mimics, as well as new immunological kits, devices, and reagents have been developed for both the immunodiagnosis and immunotherapeutics of HPV-induced cancers. In the current review, we summarize the research progress in the immunodiagnosis and immunotherapeutics based on HPV for HPV-induced cancers. In particular, we depict the most promising serological methods for the detection of HPV infection and several therapeutical immunotherapeutics based on HPV, using immunological tools, including native mAbs, radio-labelled mAbs, affitoxins (affibody-linked toxins), intracellular single-chain antibodies (scFvs), nanobodies, therapeutical vaccines, and T-cell-based therapies. Our review aims to provide new clues for researchers to develop novel strategies and methods for the diagnosis and treatment of HPV-induced tumors.

Cellular Functions of HPV16 E5 Oncoprotein during Oncogenic Transformation

The human papillomavirus (HPV) is recognized as the main etiologic agent associated with cervical cancer. HPVs are epitheliotropic, and the ones that infect the mucous membranes are classified into low-risk (LR) and high-risk (HR) types. LR-HPVs produce benign lesions, whereas HR-HPVs produce lesions that may progress to cancer. HR-HPV types 16 and 18 are the most frequently found in cervical cancer worldwide. E6 and E7 are the major HPV oncogenic proteins, and they have been profusely studied. Moreover, it has been shown that the HPV16 E5 (16E5) oncoprotein generates transformation, although the molecular mechanisms through which it carries out its activity have not been well defined. In contrast to E6 and E7, the E5 open reading frame is lost during the integration of the episomal HPV DNA into the cellular genome. This suggests that E5 acts at the early stages of the transformation process. In this review, we focused on the biochemical characteristics and functions of the HPV E5 oncoprotein, mainly on its association with growth factor receptors and other cellular proteins. Knowledge of the HPV E5 biology is important to understand the role of this oncoprotein in maintaining the viral cycle through the modulation of proliferation, differentiation, and apoptosis, as well as the alteration of other processes, such as survival, adhesion, migration, and invasion during early carcinogenesis. Finally, we summarized recent research that uses the E5 oncoprotein as a therapeutic target, promising a novel approach to the treatment of cervical cancer in its early stages.

External validation of OroGrams as a predictive model for overall and progression-free survival in Scottish patients with oropharyngeal squamous cell carcinoma: a retrospective cohort study

The aims of this study were to externally validate the OroGrams (oropharyngeal cancer survival calculator) nomogram in a Scottish cohort with high endemic smoking rates, and to compare survival rates with the original validation cohort. A retrospective cohort study in Greater Glasgow and Clyde ENT and OMFS departments was performed to investigate survival outcomes of patients with oropharyngeal squamous cell carcinoma (OPSCC) from January 2012 - December 2017. The main outcome measures were progression-free (PFS) and overall survival (OS), and Kaplan Meier curves. The predictive accuracy of OroGrams was investigated for survival probabilities at one, three, and five years. Smoking and HPV-negative cancer rates were significantly higher in Scottish patients than in the UK consortium cohort. A greater proportion of Scottish patients had advanced UICC8 stages. PFS in patients with HPV-negative cancer appeared better in the Scottish cohort than in the original cohort. Calculated mean standardised Brier scores for PFS and OS were below 0.2 at all three follow-up points, suggesting good overall prognostic accuracy, but there was wide variation between predictive accuracy in individual patients. OroGrams shows prognostic accuracy at one-year follow up in Scotland. The accuracy decreases with longer follow-up periods.

A Phase 1 Trial Assessing the Safety and Tolerability of a Therapeutic DNA Vaccination Against HPV16 and HPV18 E6/E7 Oncogenes After Chemoradiation for Cervical Cancer

PURPOSE

This study assessed the safety and tolerability of therapeutic immunization against the human papillomavirus (HPV) viral oncoproteins E6 and E7 in patients with cervical cancer after chemoradiation.

METHODS AND MATERIALS

MEDI0457 (INO-3112) is a DNA-based vaccine targeting E6 and E7 of HPV-16/18 that is coinjected with an IL-12 plasmid followed by electroporation with the CELLECTRA 5P device. At 2 to 4 weeks after chemoradiation, patients with newly diagnosed stage IB1-IVA (cohort 1) or persistent/recurrent (cohort 2) cervical cancers were treated with 4 immunizations of MEDI0457 every 4 weeks. The primary endpoints were incidence of adverse events and injection site reactions. Immune responses against HPV antigens were measured by ELISpot for interferon-γ (IFNγ), enzyme-linked immunosorbent assay for antibody responses and multiplexed immunofluorescence for immune cells in cervical biopsy specimens.

RESULTS

Ten patients (cohort 1, n = 7; cohort 2, n = 3) with HPV16 (n = 7) or HPV18 (n = 3) cervical cancers received MEDI0457 after chemoradiation. Treatment-related adverse events were all grade 1, primarily related to the injection site. Eight of 10 patients had detectable cellular or humoral immune responses against HPV antigens after chemoradiation and vaccination: 6 of 10 patients generated anti-HPV antibody responses and 6 of 10 patients generated IFNγ-producing T cell responses. At the completion of chemoradiation and vaccination, cervical biopsy specimens had detectable CD8⁺ T cells and decreased PD-1⁺CD8⁺, PD-L1⁺CD8⁺, and PD-L1⁺CD68⁺ subpopulations. All patients cleared detectable HPV DNA in cervical biopsies by completion of chemoradiation and vaccination.

CONCLUSIONS

Adjuvant MEDI0457 is safe and well tolerated after chemoradiation for locally advanced or recurrent cervical cancers, supporting further investigation into combining tumor-specific vaccines with radiation therapy.

Multifunctional CRISPR-Cas9 with engineered immunosilenced human T cell epitopes

The CRISPR-Cas9 system has raised hopes for developing personalized gene therapies for complex diseases. Its application for genetic and epigenetic therapies in humans raises concerns over immunogenicity of the bacterially derived Cas9 protein. Here we detect antibodies to Streptococcus pyogenes Cas9 (SpCas9) in at least 5% of 143 healthy individuals. We also report pre-existing human CD8+T cell immunity in the majority of healthy individuals screened. We identify two immunodominant SpCas9 T cell epitopes for HLA-A*02:01 using an enhanced prediction algorithm that incorporates T cell receptor contact residue hydrophobicity and HLA binding and evaluated them by T cell assays using healthy donor PBMCs. In a proof-of-principle study, we demonstrate that Cas9 protein can be modified to eliminate immunodominant epitopes through targeted mutation while preserving its function and specificity. Our study highlights the problem of pre-existing immunity against CRISPR-associated nucleases and offers a potential solution to mitigate the T cell immune response.

Possible immunogenicity of the Cas9 protein raises concerns about therapeutic applications. Here the authors identify pre-existing CD8+T-cell immunity in healthy individuals and in response modify Cas9 to remove the immunodominant epitopes.

Immune Evasion by Head and Neck Cancer: Foundations for Combination Therapy

Head and neck cancer is disfiguring and deadly, and contemporary treatment has fallen short in terms of morbidity and mortality. The rich immune infiltrate within these tumors designates them as prime candidates for immunotherapy and success with these drugs has been documented for recurrent and metastatic head and neck cancer. Still, single-agent immunotherapy has generated either only transient responses or durable response in only a minority subset of patients. Mapping the immune escape mechanisms enacted by head and neck cancer within the tumor microenvironment allows for rational design of strategies to overcome this tolerance. We outline the immune pathway derangements within the head and neck cancer microenvironment and discuss combination treatment strategies to overcome the limitations of immunologic monotherapy.

Emerging technologies for the detection of viral infections

Viruses represent one of the major environmental agents that cause human illness and disease. However, the ability to diagnose viral infections is limited by detection capability and scope. Here we describe several emerging technologies that provide rapid and/or high-quality viral diagnostic information. Two technologies, novel CRISPR-based diagnostics and a portable DNA sequencing instrument, are uniquely suited to increase the number of viral agents analyzed, even in point of care settings. We also discuss a phage-based method for generating comprehensive viral profiles of previous exposure/infection and a fluid-phase immunoassay that yields highly quantitative viral antibody analyses. Future applications of these approaches will accelerate on-site clinical diagnosis of viral infections and provide insights into the role viruses play in complex diseases.

Human Papilloma Virus Specific Immunogenicity and Dysfunction of CD8+ T Cells in Head and Neck Cancer

Human papillomavirus subtype 16 (HPV16) is the primary cause of an increasing number of head and neck squamous cell carcinomas (HNSCC), providing strong rationale for T-cell immune therapies against HPV⁺ HNSCC. Here we assess immunogenicity of HPV16-specific CD8⁺ T cells (CTL) and characterize HPV-specific mechanisms of T-cell dysfunction. We identified 16 strong and 29 moderately immunogenic CTL-epitopes from HPV16 E2, E6, and E7 antigens restricted by 12 common HLA class I alleles. E2-specific CTL-reactivity was higher in patients with HPV⁺ HNSCC than in healthy controls (>3-fold; P = 0.026). Patient-derived E2, E6, and E7 peripheral CTLs exhibited heterogeneity in dysfunctional phenotypes. Immunogenomic analyses of 119 HNSCC transcriptomes revealed high T-cell infiltration and dysfunction in HPV⁺ HNSCC and correlation of HPV antigen expression with T-cell exhaustion gene signatures. Indoleamine 2,3-dioxygenase (IDO-1) was strongly expressed in HPV⁺ HNSCC versus HPV^- HNSCC (P = 0.001) and correlated with E7 expression (R ² = 0.84; P = 0.033). Combination treatment with PD-1 blockade and IDO-1 inhibition overcame profound CTL-dysfunction, enhancing HPV⁺ HNSCC sensitivity to CTL-cytotoxicity in vitro (up to 10-fold in E7-CTLs, P = 0.011). Our findings implicate mechanisms of T-cell escape in HPV⁺ HNSCC, wherein high tumoral HPV-antigen load results in high expression of immune dysfunction genes on tumor cells (e.g., IDO-1), and dysfunction of HPV-specific CTLs (e.g., E7, E2-CTLs). The HPV16 CTL-epitopes identified in this study, in combination with blockade of HPV⁺ HNSCC-specific PD-1/IDO-1 checkpoints, may be useful for targeted immunotherapy.Significance: This study evaluates the HPV antigen T-cell immunogenicity role of inhibitory receptors and other exhaustion markers in the cytotoxic function of HPV antigen-specific CTLs and identifies combined inhibition of PD-1/IDO-1 as a strategy to enhance CTL targeting of HPV⁺ HNSCC. Cancer Res; 78(21); 6159-70. ©2018 AACR.

A TGF-β1 genetic variant at the miRNA187 binding site significantly modifies risk of HPV16-associated oropharyngeal cancer

TGF-β1rs1982073 polymorphism at the miRNA-187 binding site may alter TGF-β1 expression and function, and thereby this polymorphism (genotype CT/CC) increases cancer susceptibility. HPV16 L1 seropositivity is associated with the risk of oral squamous cell carcinoma (OSCC), including oropharyngeal squamous cell carcinoma (OPSCC) and oral cavity squamous cell carcinoma (OCSCC). Thus, we hypothesized that TGF-β1rs1982073 polymorphism at the miRNA-187 binding site combined with HPV16 L1 seropositivity may have a joint effect on OSCC susceptibility. We determined the genotypes of TGF-β1rs1982073 and HPV16 status in 325 OSCC subjects and 335 cancer-free controls in the non-Hispanic white population, and used logistic regression models to evaluate the joint effects on OSCC susceptibility. TGF-β1rs1982073 polymorphism (CT/CC genotype) combined with HPV16 L1 seropositivity increased the risk of OSCC via joint effects, particularly in OPSCC subjects who were never-smokers (OR, 165.9; 95% CI, 28.6-960.4) or never-drinkers (OR, 196.0; 95% CI, 28.2-1,000.0), respectively. Younger subjects had a higher risk of OPSCC than older subjects (OR, 23.5; 95% CI, 6.3-87.0 vs. OR, 6.0; 95% CI, 1.7-17.9, respectively). The significant associations between this polymorphism and HPV16-associated OSCC and OPSCC were also observed. However, OCSCC subjects did not have similar results. Our findings suggest that the joint effects of TGF-β1rs1982073 and HPV16 L1 seropositivity can increase risk of HPV16-associated oral cancer, particularly in OPSCC subjects who are never-smokers, never-drinkers and young. This result may help us understand the tumorigenesis process and improve early detection, which are critical for prevention and intervention strategies. However, larger studies are needed to validate our findings.

Association of antibody to E2 protein of human papillomavirus and p16INK4A with progression of HPV-infected cervical lesions

Human papillomavirus (HPV) E2 and L1 proteins are expressed in cervical cells during the lytic stage of infection. Overexpression of p16^INK4A is a biomarker of HPV-associated cervical neoplasia. This study investigated antibodies to HPV16 E2, HPV16 L1, and p16^INK4A in sera from women with no squamous intraepithelial lesion (No-SIL) of the cervix, low-grade SIL, high-grade SIL, and cervical squamous cell carcinoma (SCC). HPV DNA was detected by polymerase chain reaction. Anti-E2, -L1, and -p16^INK4A antibodies in sera were determined by western blot. Among 116 samples, 69 (60%) were HPV DNA-positive. Percentages seropositive for anti-E2, -L1, and -p16^INK4A antibodies were 39.6, 22.4, and 23.3%, respectively. Anti-E2 antibody was significantly correlated with HPV DNA-positive cases. Eighty-seven women (75%) were regarded as infected with HPV, having at least one positive result from HPV DNA, L1, or E2 antibody. Antibody to p16^INK4A was associated with HPV infection (odds = 5.444, 95% CI 1.203-24.629, P = 0.028) and precancerous cervical lesions (odds = 5.132, 95% CI 1.604-16.415, P = 0.006). Interestingly, the concurrent detection of anti-E2 and -p16^INK4A antibodies was significantly associated with HPV infection (odds = 1.382, 95% CI 1.228-1.555, P = 0.044). These antibodies might be good candidate biomarkers for monitoring HPV-associated cervical lesion development to cancer.

Screening for human papillomavirus-driven oropharyngeal cancer: Considerations for feasibility and strategies for research

The incidence and burden of human papillomavirus (HPV)‐driven oropharyngeal cancer is expected to increase for decades, thus motivating discussions regarding possibilities for screening. This article addresses issues related to the validity and timeliness of screening for HPV‐driven oropharyngeal cancer, and raises important questions, highlights deficits and confusion in the existing literature, and proposes needed steps in the research agenda.

Comprehensive review of genetic factors contributing to head and neck squamous cell carcinoma development in low-risk, nontraditional patients

BACKGROUND

The past 2 decades have seen an increased incidence of head and neck squamous cell carcinoma (HNSCC) in a nontraditional, low-risk patient population (ie, ≤45 years of age, no substance use history), owing to a combination of human papillomavirus (HPV) infection and individual genetic variation.

METHODS

Articles positing genetic variants as contributing factors in HNSCC incidence in low-risk, nontraditional patients were identified using a PubMed search, reviewed in detail, and concisely summarized herein.

RESULTS

Recent data suggest that common polymorphisms in DNA repair enzymes, cell-cycle control proteins, apoptotic pathway members, and Fanconi anemia-associated genes likely modulate susceptibility to HNSCC development in low-risk, nontraditional patients.

CONCLUSION

At present, there is a lack of robust, comprehensive data on genetic drivers of oncogenesis in low-risk patients and a clear need for further research on genetic alterations underlying the rising incidence of HNSCC in low-risk, nontraditional patients.

Diagnostic accuracy of serum antibodies to human papillomavirus type 16 early antigens in the detection of human papillomavirus-related oropharyngeal cancer

BACKGROUND

Because of the current epidemic of human papillomavirus (HPV)-related oropharyngeal cancer (OPC), a screening strategy is urgently needed. The presence of serum antibodies to HPV-16 early (E) antigens is associated with an increased risk for OPC. The purpose of this study was to evaluate the diagnostic accuracy of antibodies to a panel of HPV-16 E antigens in screening for OPC.

METHODS

This case-control study included 378 patients with OPC, 153 patients with nonoropharyngeal head and neck cancer (non-OPC), and 782 healthy control subjects. The tumor HPV status was determined with p16 immunohistochemistry and HPV in situ hybridization. HPV-16 E antibody levels in serum were identified with an enzyme-linked immunosorbent assay. A trained binary logistic regression model based on the combination of all E antigens was predefined and applied to the data set. The sensitivity and specificity of the assay for distinguishing HPV-related OPC from controls were calculated. Logistic regression analysis was used to calculate odds ratios with 95% confidence intervals for the association of head and neck cancer with the antibody status.

RESULTS

Of the 378 patients with OPC, 348 had p16-positive OPC. HPV-16 E antibody levels were significantly higher among patients with p16-positive OPC but not among patients with non-OPC or among controls. Serology showed high sensitivity and specificity for HPV-related OPC (binary classifier: 83% sensitivity and 99% specificity for p16-positive OPC).

CONCLUSIONS

A trained binary classification algorithm that incorporates information about multiple E antibodies has high sensitivity and specificity and may be advantageous for risk stratification in future screening trials. Cancer 2017;123:4886-94. © 2017 American Cancer Society.

Pre-diagnostic dynamic HPV16 IgG seropositivity and risk of oropharyngeal cancer

OBJECTIVE

The aim of this study was to determine the association of HPV16 antibodies (Abs) and oropharyngeal cancer (OPC) risk in sera obtained prior to clinical diagnosis.

METHODS

We identified 92 participants with incident OPC and 460 matched controls from the Janus Serum Bank Cohort in Norway. Archived tumor specimens were requested for a subset of the cases. Serum samples were collected from cases, on average, 9.3years before diagnosis (range, 0.1-14.9years). Ten cases had serum samples from multiple time points. IgG seropositivity to 8 HPV16 antigens was determined, and a logistic regression classifier of a panel of all early-antigen (EA) Abs for the predictive diagnosis of OPC was applied.

RESULTS

HPV16 EA seropositivity was present in 25.0% of patients with OPC and 7.6% of controls (odds ratio (OR), 4.1; 95% CI, 2.3-7.2, p<0.0001). Abs to E2 were strongly associated with cases 0-2years pre- diagnosis (OR, 150.1; 95% CI, 27.4-1040.0, p<0.0001), and the probability of seropositivity was inversely associated with time to diagnosis (OR, 0.7 per additional year; 95% CI, 0.6-0.9, p=0.0002). Abs to E2 were also strongly associated with tumor HPV status (OR, 35.6; 95% CI, 8.7-200.0, p<0.0001). A positive score on the binary classifier was associated with an overall OR of 15.8 (95% CI, 5.6-53.4) compared with controls (p<0.05), and was strongly associated with tumor HPV status (OR, 27.4; 95% CI, 8.6-99.6, p<0.001).

CONCLUSIONS

HPV16 Abs are detectable years prior to diagnosis of OPC, and the probability of seropositivity increases closer to diagnosis.

Serum Immune Profiling for Early Detection of Cervical Disease

Background: The most recent (2012) worldwide estimates from International Agency for Research on Cancer indicate that approximately 528,000 new cases and 270,000 deaths per year are attributed to cervical cancer worldwide. The disease is preventable with HPV vaccination and with early detection and treatment of pre-invasive cervical intraepithelial neoplasia, CIN. Antibodies (Abs) to HPV proteins are under investigation as potential biomarkers for early detection.

Methods: To detect circulating HPV-specific IgG Abs, we developed programmable protein arrays (NAPPA) that display the proteomes of two low-risk HPV types (HPV6 and 11) and ten oncogenic high-risk HPV types (HPV16, 18, 31, 33, 35, 39, 45, 51, 52 and 58). Arrays were probed with sera from women with CIN 0/I (n=78), CIN II/III (n=84), or invasive cervical cancer (ICC, n=83).

Results: Abs to any early (E) HPV protein were detected less frequently in women with CIN 0/I (23.7%) than women with CIN II/III (39.0%) and ICC (46.1%, p<0.04). Of the E Abs, anti-E7 Abs were the most frequently detected (6.6%, 19.5%, and 30.3%, respectively). The least frequently detected Abs were E1 and E2-Abs in CIN 0/I (1.3%) and E1-Abs in CIN II/III (1.2%) and ICC (7.9%). HPV16-specific Abs correlated with HPV16 DNA detected in the cervix in 0% of CIN 0/I, 21.2% of CIN II/III, and 45.5% of ICC. A significant number (29 - 73%) of E4, E7, L1, and L2 Abs had cross-reactivity between HPV types.

Conclusion: HPV protein arrays provide a valuable high-throughput tool for measuring the breadth, specificity, and heterogeneity of the serologic response to HPV in cervical disease.

Evaluation of type-specific antibodies to high risk-human papillomavirus (HPV) proteins in patients with oropharyngeal cancer

OBJECTIVES

High risk human papillomavirus (HR-HPV) infection leads to a subgroup of oropharyngeal cancer (OPSCC) characterized by improved treatment response. However an universally accepted definition of an HR-HPV-attributable cancer is lacking.

METHODS

Detailed, type-specific HPV antibody responses were analyzed by multiplex serology in HR-HPV-attributable OPSCC patients, defined by p16^INK4A overexpression and HR-HPV DNA detection by PCR amplification and sequencing.

RESULTS

Fifty patients were prospectively enrolled. 26/50 (52%) tumor samples were positive for both p16^INK4A expression and HR-HPV DNA (22 HPV16, 4 HPV33). Seropositivity was present in 26/26 HPV-attributable OPSCC and one p16^INK4A-positive/HPV DNA-negative case. The sensitivity and specificity to diagnose an HR-HPV-attributable tumor was 100% and 96%, respectively for anti-E6 reactivity, 82% and 100%, respectively for anti-E2 reactivity, and clearly lower for anti-E7, anti-E1, anti-E4 and anti-L1-reactivity. 3yr-overall (OS) and disease specific survival (DSS) was higher in patients with HR-HPV-attributable tumors (OS 88% vs 64%, p=0.02; DSS 90% vs 80%, p=0.07) and seropositive patients (OS 88% vs 62%, p=0.01; DSS 92% vs 78%, p=0.05) than HR-HPV-negative or seronegative patients.

CONCLUSIONS

Detection of HR-HPV type-specific antibodies highly correlated with HPV-attributable OPSCC and was associated with better survival. HR-HPV antibodies are promising diagnostic, prognostic and potentially screening markers in HR-HPV-attributable OPSCC.

Is there an increased risk of cancer among spouses of patients with an HPV-related cancer: A systematic review

BACKGROUND

High-risk human papillomaviruses (HR-HPV) are the cause of most ano-genital cancers and a fast growing subset of oropharyngeal cancer. As these malignancies occur as a result of an HPV- infection transmitted through intimate contact, many patients with HPV- induced cancer and their partners are concerned about HPV-transmission and the potential partners' cancer risk. Few studies have addressed this issue and whether the HPV-related cancer risk of partners of patients with HPV-related cancers is comparable to or greater than that of the general population.

METHODS

We performed a systematic review of the published literature addressing this issue. Out of 1055 references screened, 53 articles were found eligible for inclusion.

RESULTS

Regarding the issue of coincidence of HPV-induced oropharyngeal and/or anogenital cancers in couples, 13 case-reports or case-series were reported and 9 larger studies based on population-registries. Four of these registry studies showed an increased risk of cervical cancer in the partner while four did not. Among the four positive studies, odds ratios for the development of HPV-related cancer among spouses were between 2.6 and 6.7. One study showed an increased risk of tongue or tonsil cancer among husbands of women with cervical dysplasia or cancer. Overall the absolute risk increase in all these studies was small, on the order of 1-3%, although potentially underestimated. Indeed, all these studies have assessed partner's cancer risk at only one anatomical site whereas HPV- related malignancies can affect different locations.

CONCLUSION

This systematic review suggests a small trend of increase risk in HPV-associated cancers among spouses of patients with HPV-related cancer.

Human papillomavirus (HPV) 16 antibodies at diagnosis of HPV-related oropharyngeal cancer and antibody trajectories after treatment

OBJECTIVES

Despite the fact that HPV-driven oropharyngeal cancer (HPV-OPC) has relatively low recurrence rates, intensive post-therapy monitoring remains the standard of care. Post-treatment biomarkers are needed to risk stratify HPV-OPC patients for more individualized surveillance intensity and which remain at higher recurrence risk.

MATERIALS AND METHODS

115 HPV-OPC patients (ascertained by p16 immunohistochemistry and/or in-situ hybridization) from a multicenter prospective case study (HOTSPOT) had blood collected at diagnosis, and 64 of these also had blood collected at post-treatment follow-up visits for up to two years. Samples were centrally tested for antibodies to the L1, E1, E2, E4, E6, and E7 proteins of HPV16.

RESULTS

At diagnosis, most HPV-OPC cases were seropositive to HPV16 E6 (85%). In post therapeutic samples, HPV16 antibody level decreased slowly over time, but only 3 (of 51 cases seropositive at enrollment) dropped low enough to be classified as seronegative. At 3years after diagnosis, cumulative risk of recurrence was 10.2% and 0% in HPV16 E6 seropositive and E6 seronegative HPV-OPC cases, respectively (p=0.18). Risk of recurrence was increased, although not statistically significant, in those with higher HPV16 E6 antibody levels at diagnosis (per log antibody level, hazard ratio [HR]=1.81, 95%CI=0.47-6.92).

CONCLUSION

This study confirms the high seroprevalence of HPV oncogenic antibodies at diagnosis of HPV-OPC. HPV16 E6 antibody levels decrease after treatment, but most cases remain seropositive for up to two years. HPV16 E6 antibody levels at diagnosis did not appear to be a strong predictor of recurrence.

E6 and E7 Antibody Levels Are Potential Biomarkers of Recurrence in Patients with Advanced-Stage Human Papillomavirus-Positive Oropharyngeal Squamous Cell Carcinoma

Purpose: There is a paucity of biomarkers to predict failure in human papillomavirus-positive (HPV⁺) oropharyngeal squamous cell carcinoma (OPSCC) following curative therapy. E6/E7 viral oncoproteins are constitutively expressed in HPV⁺ tumors and highly immunogenic, resulting in readily detected serum antibodies. The purpose of this study is to determine whether serum E6 and E7 antibody levels can potentially serve as a biomarker of recurrence in patients with HPV+OPSCC.Experimental Design: We evaluated E6/E7 antibody levels in patients with previously untreated, advanced stage (III, IVa-b), HPV+OPSCC receiving definitive chemoradiation under a uniform protocol from 2003 to 2010. Baseline and longitudinal serum samples were obtained from our archived repository. E6/E7 serum levels were measured using a glutathione-S-transferase capture ELISA and quantified by approximating the area under the dilution curve, and were analyzed using ANOVA and linear mixed model for longitudinal analysis.Results: We compared 22 HPV+OPSCC patients who developed recurrence with 30 patients who remained disease-free. There were no differences in T classification, N classification, disease subsite, or smoking status between the groups. In a longitudinal analysis, recurrent patients had significantly higher E6 and E7 serum antibody levels than the nonrecurrent patients over the follow-up period (P = 0.02 and P = 0.002, respectively). Patients who recurred had a lower clearance of E7 antibody than patients who remained disease-free (P = 0.0016).Conclusions: Patients with HPV+OPSCC whose disease recurs have a lower clearance of E6 and E7 antibodies than patients who do not have recurrence. The ratio of E7 antibody at disease recurrence compared with baseline is potentially a clinically significant measurement of disease status in HPV+OPSCC. Clin Cancer Res; 23(11); 2723-9. ©2016 AACR.

Oral and oropharynx cancer in South America

Objectives:

To describe the incidence and mortality of oral and oropharynx cancers in South America using available public databases and to discuss the main pitfalls for acquiring reliable data.

Methods:

The incidence data for oral cavity and oropharynx cancers for South America were obtained from Cancer Incidence in Five Continents/International Agency for Research on Cancer for the period 1998–2007. Mortality rates in South America were obtained from the World Health Organization/IARC database for the period 1999–2012. The number of cases for Brazil was obtained from the National Cancer Institute/missing stage for the period 2000–2010, whereas the São Paulo cancer registry was used to collect data from the most populated state in Brazil for the period 2000–2008.

Results:

The incidence of oral and oropharynx cancers in South America varied, with the highest rates observed in Brazil among males. The mortality data in selected South American countries ranged from 0.72 to 6.04/100,000 and the proportion of ill-defined deaths in South America varied from 5.0% to 22.0%. Mortality trends for males decreased about 2.5% in most of the countries, excluding Brazil, whereas among females, a significant decrease occurred only in Colombia, with an increase in Brazil and Peru.

Conclusion:

Although there is a lack of reliable databases in South America, the available data demonstrate a decrease in mortality trends in most countries and the highest incidence in Brazil. The development and improvement of national cancer public databases in South America are highly desirable and necessary to better understand the characteristics and distribution of these neoplasms.

Application of flat panel OLED display technology for the point-of-care detection of circulating cancer biomarkers

Point-of-care molecular diagnostics can provide efficient and cost-effective medical care, and they have the potential to fundamentally change our approach to global health. However, most existing approaches are not scalable to include multiple biomarkers. As a solution, we have combined commercial flat panel OLED display technology with protein microarray technology to enable high-density fluorescent, programmable, multiplexed biorecognition in a compact and disposable configuration with clinical-level sensitivity. Our approach leverages advances in commercial display technology to reduce pre-functionalized biosensor substrate costs to pennies per cm². Here, we demonstrate quantitative detection of IgG antibodies to multiple viral antigens in patient serum samples with detection limits for human IgG in the 10 pg/mL range. We also demonstrate multiplexed detection of antibodies to the HPV16 proteins E2, E6, and E7, which are circulating biomarkers for cervical as well as head and neck cancers.

Human Papillomavirus (HPV) 16 E6 seropositivity is elevated in subjects with oral HPV16 infection

INTRODUCTION

Human Papillomavirus (HPV) 16 E6 serum antibodies are common in people with HPV-related oropharyngeal cancers (HPV-OPC), but not the general population. We explored HPV16 seroprevalence in people with and without oral HPV16 infection, the cause of HPV-OPC.

METHODS

Oral rinse samples were collected semiannually and tested for 36 types of HPV DNA by PCR. HPV16 E6 serum antibodies were tested at the visit of first oral HPV detection in participants with prevalent (n=54), or incident (n=39) oral HPV16 DNA; or at baseline in matched participants with no oral HPV16 DNA (n=155) using multiplex serology assay. Predictors of seropositivity were examined using logistic regression.

RESULTS

HPV16 E6 seropositivity (7.5% vs 0.7%; p=0.005) but not seropositivity to the other HPV16 antigens, was significantly more common in those with than without oral HPV16 infection. There were only 8 HPV16 E6 seropositive participants, but oral HPV16 DNA remained a strong predictor of E6 seropositivity after adjustment for other risk factors (aOR=14.6 95%CI, 1.7-122.5). Seroprevalence was similar in those with prevalent (7.4%; 4/54), and incident (7.7%; 3/39) oral HPV16 infection (p=1.00). E6 seroprevalence was associated with reduced oral HPV16 clearance, but was not statistically significant (HR=0.65 95% CI, 0.16-2.70). Seropositive participants were primarily male (87.5%), HIV-positive (75.0%; median CD4 cell-count of 840) and had oral HPV16 DNA (87.5%). History of an HPV-related cancer (0/8) or HPV-related anogenital dysplasia (1/8) was rare, and 4 participants had recent screening showing no anogenital dysplasia.

DISCUSSION

HPV16 E6 seropositivity was higher among people with than without oral HPV16 infection, despite no known anogenital disease in these participants.

Human papillomavirus (HPV) infection: a Mozambique overview

Human Papillomavirus is agent of the most common sexually transmitted disease which is able to infect mucosal and cutaneous membranes of the anogenital region, upper aerodigestive tract, and other head and neck mucosal regions. Although mainly HPV infection can be asymptomatic and transient, it may persist and give rise to various lesions such as warts, condyloma dysplasia and cancers depending on low or high risk type of HPV infection. Moreover, growing recent evidence suggests a role of this virus in male and female fertility. To date no effective prevention, test, treatment and control strategies are provided for people in developing countries despite the reported high incidence of HPV both in women and men. This paper reviews the more recent literature about HPV infection highlighting epidemiology, related pathologies and possible fertility effects of HPV in male and female with particular attention to the Mozambique context.

Programmable protein arrays for immunoprofiling HPV-associated cancers

Over 600,000 cancers each year are attributed to the human papillomavirus (HPV), including cervical, anogenital and oropharyngeal cancers (OPC). A key challenge in understanding HPV immunobiology is the diversity of oncogenic HPV types and the need for multiplexed display of HPV antigens to measure antibody responses. We have generated custom HPV protein microarrays displaying 98 proteins as C-terminal GST fusion proteins, representing eight antigens of two low-risk HPV types (HPV6 and 11) and ten oncogenic high-risk HPV types (HPV16, 18, 31, 33, 35, 39, 45, 51, 52 and 58). We demonstrate robust and reproducible protein expression of 96/98 of the antigens using a human cell lysate expression system. The target epitopes and specificities of four monoclonal antibodies were identified. Using sera from ten patients with newly diagnosed OPC and ten controls, we demonstrate specific IgG seroreactivity to HPV16 E1, E2, and E7 (a fold increase of 1.52, 2.19 and 1.35 in cases vs. controls, respectively, all p < 0.005), confirming our prior data on an ELISA platform. We also detect HPV52 E7 Abs in serum from a patient with cervical cancer. The HPV protein array has potential for rapid identification of serologic responses to 12 HPV types.

Serum Antibodies to HPV16 Early Proteins Warrant Investigation as Potential Biomarkers for Risk Stratification and Recurrence of HPV-Associated Oropharyngeal Cancer

Human papillomavirus (HPV) is responsible for increasing incidence of oropharyngeal cancer. At present, there are no biomarkers in the surveillance algorithm for HPV-positive oropharyngeal cancer (HPV-OPC). HPV16 E6 antibody precedes oropharyngeal cancer diagnosis. If HPV16 E6 indeed precedes primary diagnosis, it is similarly expected to precede disease recurrence and may have a potential role as a biomarker for surveillance of HPV-OPC. To determine whether HPV antibody titers have a potential role as early markers of disease recurrence or prognosis, a retrospective pilot study was designed to determine whether HPV16 early antibody titers E6, E7, E1, and E2 decrease after treatment of HPV16-positive OPC. Trends in pretreatment, early (≤6 months after treatment), and late posttreatment (>6 months after treatment) HPV16 antibody titers were examined. There were 43, 34, and 52 subjects with serum samples available for pretreatment, early, and late posttreatment intervals. Mean pretreatment antibody levels were higher than posttreatment antibody levels. Average antibody levels decreased significantly over time for E6 (Ptrend = 0.001) and E7 (Ptrend < 0.001). Six disease recurrences were observed during the follow-up period (median, 4.4 years). In univariate analysis, a log-unit increase in pretreatment E6 titer was significantly associated with increased risk of disease recurrence (HR, 5.42; 95% CI, 1.1-25.7; P = 0.03). Therefore, levels of antibodies to HPV16 early oncoproteins decline after therapy. Higher E6 titers at diagnosis are associated with significant increases in the risk of recurrence. These data support the prospective evaluation of HPV16 antibodies as markers of surveillance and for risk stratification at diagnosis.

Biologic predictors of serologic responses to HPV in oropharyngeal cancer: The HOTSPOT study

OBJECTIVES

We hypothesized that viral and host factors impact the serologic responses to HPV early antigens in HPV-positive oropharyngeal cancer (HPVOPC).

MATERIALS AND METHODS

We conducted a multicenter study to measure HPV16-specific IgG among patients with HPVOPC, their long-term sexual partners, and healthy volunteers. Risk factor surveys and rinse and gargle specimens were collected. Peripheral blood samples at diagnosis were evaluated for IgG Abs to HPV16 antigens using a programmable ELISA assay. Predictors for HPV16 serologic responses were evaluated using univariate and multivariable linear regression.

RESULTS

116 patients with HPVOPC, 43 partners, and 81 healthy volunteers were enrolled and had baseline sera for analysis. Cases were primarily male (90%), with a median age of 56 years. Abs to E1, E2, E6 or E7 antigens were detected more often in HPVOPC compared with volunteers or partner sera (p<0.0001). HPV16 Abs to at least one early protein (E1, E2, E4, E5, E6, or E7) were detected in the sera of 90.6% of cases, 0% of partners and 7.4% of healthy volunteers. Gender, race, sexual behavior, and viral integration were not associated with antibody response. Younger age and higher oral HPV16 copy number were associated with higher HPV16 E6 and NE2 antibody levels.

CONCLUSIONS

HPV16 seroreactivity is commonly detected among patients with HPVOPC at diagnosis, but not among partners or healthy volunteers. Seroreactivity among cases are correlated with viral load and stage and not with other demographic or behavioral factors. Positive HPV16 serology was strongly associated with HPV 16 oropharyngeal cancer.