Evaluation of HPV-16 and HPV-18 specific antibody measurements in saliva collected in oral rinses and merocel® sponges

Assessing the reduction of viral infectivity in HPV16/18-positive women after one, two, and three doses of Gardasil-9 (RIFT): Study protocol

Human Papillomavirus (HPV) prophylactic vaccination has proven effective in preventing new infections, but it does not treat existing HPV infections or associated diseases. Hence, there is still an important reservoir of HPV in adults, as vaccination programs are mainly focused on young women. The primary objective of this non-randomized, open-label trial is to evaluate if a 3-dose regimen of Gardasil-9 in HPV16/18-positive women could reduce the infective capacity of their body fluids. We aim to assess if vaccine-induced antibodies could neutralize virions present in the mucosa, thus preventing the release of infective particles and HPV transmission to sexual partners. As our main endpoint, the E1^E4-HaCaT model will be used to assess the infectivity rate of cervical, anal and oral samples, obtained from women before and after vaccination. HPV DNA positivity, virion production, seroconversion, and the presence of antibodies in the exudates, will be evaluated to attribute infectivity reduction to vaccination. Our study will recruit two different cohorts (RIFT-HPV1 and RIFT-HPV2) of non-vaccinated adult women. RIFT-HPV1 will include subjects with an HPV16/18 positive cervical test and no apparent cervical lesions or cervical lesions eligible for conservative treatment. RIFT-HPV2 will include subjects with an HPV16/18 positive anal test and no apparent anal lesions or anal lesions eligible for conservative treatment, as well as women with an HPV16/18 positive cervical test and HPV-associated vulvar lesions. Subjects complying with inclusion criteria for both cohorts will be recruited to the main cohort, RIFT-HPV1. Three doses of Gardasil-9 will be administered intramuscularly at visit 1 (0 months), visit 2 (2 months) and visit 3 (6 months). Even though prophylactic HPV vaccines would not eliminate a pre-existing infection, our results will determine if HPV vaccination could be considered as a new complementary strategy to prevent HPV-associated diseases by reducing viral spread. Trial registration: https://clinicaltrials.gov/ct2/show/NCT05334706.

Clinical Assessment of SARS-CoV-2 Antibodies in Oral Fluids Following Infection and Vaccination

BACKGROUND

SARS-CoV-2 variants continue to circulate globally, even within highly vaccinated populations. The first-generation SARS-CoV-2 vaccines elicit neutralizing immunoglobin G (IgG) antibodies that prevent severe COVID-19 but induce only weak antibody responses in mucosal tissues. There is increasing recognition that secretory immunoglobin A (SIgA) antibodies in the upper respiratory tract and oral cavity are critical in interrupting virus shedding, transmission, and progression of disease. To fully understand the immune-related factors that influence SARS-CoV-2 dynamics at the population level, it will be necessary to monitor virus-specific IgG and SIgA in systemic and mucosal compartments.

CONTENT

Oral fluids and saliva, with appropriate standardized collection methods, constitute a readily accessible biospecimen type from which both systemic and mucosal antibodies can be measured. Serum-derived IgG and immunoglobin A (IgA) are found in gingival crevicular fluids and saliva as the result of transudation, while SIgA, which is produced in response to mucosal infection and vaccination, is actively transported across salivary gland epithelia and present in saliva and passive drool. In this mini-review, we summarize the need for the implementation of standards, highly qualified reagents, and best practices to ensure that clinical science is both rigorous and comparable across laboratories and institutions. We discuss the need for a better understanding of sample stability, collection methods, and other factors that affect measurement outcomes and interlaboratory variability.

SUMMARY

The establishment of best practices and clinical laboratory standards for the assessment of SARS-CoV-2 serum and mucosal antibodies in oral fluids is integral to understanding immune-related factors that influence COVID-19 transmission and persistence within populations.

Saliva as a potential non-invasive liquid biopsy for early and easy diagnosis/prognosis of head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) are the most devastating diseases in India and southeast Asia. It is a preventable and curable disease if detected early. Tobacco and alcohol consumption are the two major risk-factors but infection of high-risk HPVs are also associated with development of predominantly oral and oropharyngeal carcinomas. Interestingly, unlike cervical cancer, HPV-induced HNSCCs show good prognosis and better survival in contrast, majority of tobacco-associated HPV-ve HNSCCs are highly aggressive with poor clinical outcome. Biomarker analysis in circulatory body-fluids for early cancer diagnosis, prognosis and treatment monitoring are becoming important in clinical practice. Early diagnosis using non-invasive saliva for oral or other diseases plays an important role in successful treatment and better prognosis. Saliva mirrors the body's state of health as it comes into direct contact with oral lesions and needs no trained manpower to collect, making it a suitable bio-fluid of choice for screening. Saliva can be used to detect not only virus, bacteria and other biomarkers but variety of molecular and genetic markers for an early detection, treatment and monitoring cancer and other diseases. The performance of saliva-based diagnostics are reported to be highly (≥95 %) sensitive and specific indicating the test's ability to correctly identify true positive or negative cases. This review focuses on the potentials of saliva in the early detection of not only HPV or other pathogens but also identification of highly reliable gene mutations, oral-microbiomes, metabolites, salivary cytokines, non-coding RNAs and exosomal miRNAs. It also discusses the importance of saliva as a reliable, cost-effective and an easy alternative to invasive procedures.

Precision and correlation of ED50 and endpoint titer method in measuring HPV vaccine immunogenicity

Cervical cancer, the second leading cause of cancer-related deaths among women, is caused by human papillomavirus (HPV), a sexually transmitted virus. Vaccination is an effective preventive measure against viral infections and subsequent development of cervical cancer. Enzyme-linked immunosorbent assay (ELISA) is commonly used to measure specific binding antibody titers and assess the immunogenicity of test vaccines in preclinical models or clinical volunteers. Two methods of deriving titers, the endpoint titer (ET) and the effective dilution producing a median maximal effective fold of dilution (ED50) with a cut-off value, are widely used. For HPV, a pseudovirion-based neutralization assay (PBNA) is used to measure functional antibody titers. The ELISA binding titers and functional PBNA titers were found to be well-correlated for all nine HPV types tested in the vaccine, consistent with previous studies on HPV 16/18. Comparing the PBNA results with the two titration methods, the ED50 method showed higher precision and a closer correlation with PBNA results, both for individual types and pooled data analysis for all nine types. When comparing the titration results of the ET method based on a cut-off value with the ED50 method using all the data points across the dilution series, the ED50 method demonstrated better precision and a stronger correlation with PBNA results.

Ultrasensitive detection of salivary SARS-CoV-2 IgG antibodies in individuals with natural and COVID-19 vaccine-induced immunity

We assessed the feasibility of a highly sensitive immunoassay method based on single molecule array (Simoa) technology to detect IgG and IgA antibodies against SARS-CoV-2 spike protein receptor binding domain (RBD) in saliva from individuals with natural or vaccine-induced COVID-19 immunity. The performance of the method was compared to a laboratory-developed SARS-CoV-2 RBD total antibody enzyme-linked immunosorbent assay (ELISA). Paired serum and saliva specimens were collected from individuals (n = 40) prior to and 2 weeks after receiving an initial prime COVID-19 vaccine dose (Pfizer/BioNTech BNT162b2 or Moderna mRNA-1273). Saliva was collected using a commercially available collection device (OraSure Inc.) and SARS-CoV-2 RBD IgG antibodies were measured by an indirect ELISA using concentrated saliva samples and a Simoa immunoassay using unconcentrated saliva samples. The IgG results were compared with paired serum specimens that were analyzed for total RBD antibodies using the ELISA method. The analytical sensitivity of the saliva-based Simoa immunoassay was five orders of magnitude higher than the ELISA assay: 0.24 pg/mL compared to 15 ng/mL. The diagnostic sensitivity of the saliva ELISA method was 90% (95% CI 76.3-97.2%) compared to 91.7% (95% CI 77.5-98.2%) for the Simoa immunoassay without total IgG-normalization and 100% (95% CI 90.3-100%) for the Simoa immunoassay after total IgG-normalization when compared to the serum ELISA assay. When analyzed using the SARS-CoV-2 RBD IgG antibody ELISA, the average relative increase in antibody index (AI) between the saliva of the post- and pre-vaccinated individuals was 8.7 (AIpost/pre). An average relative increase of 431 pg/mL was observed when the unconcentrated saliva specimens were analyzed using the Simoa immunoassay (SARS-CoV-2 RBD IgGpost/pre). These findings support the suitability of concentrated saliva specimens for the measurement of SARS-CoV-2 RBD IgG antibodies via ELISA, and unconcentrated saliva specimens for the measurement of SARS-CoV-2 RBD IgG and IgA using an ultrasensitive Simoa immunoassay.

Non-invasive Assessment of Vaccine-Induced HPV Antibodies via First-Void Urine

The potential of first-void (FV) urine as a non-invasive method to monitor human papillomavirus (HPV) vaccination has been reported, mainly focusing on urine as a sample to assess HPV DNA. Besides HPV DNA, vaccine-induced HPV antibodies originating from cervicovaginal secretions were recently shown to be detectable in FV urine as well. This presents a novel opportunity for non-invasive sampling to monitor HPV antibody status in women participating in large epidemiological studies and HPV vaccine trials. The simultaneous assessment of both HPV infection and immunogenicity on a non-invasive, readily obtained sample is particularly attractive.

Natural and vaccine-induced B cell-derived systemic and mucosal humoral immunity to human papillomavirus

Introduction: Human papillomavirus (HPV) are the causative agent of mucosal neoplasia. Both cervical, anal and oropharyngeal cancers incidence is constantly increasing, making the HPV infection, a significant worldwide concern. Together, the CD8+ T cytotoxic cell-mediated response and the HPV-specific antibody response control most of the HPV infections before the development of cancers.Areas covered: We searched the MEDLINE and EMBASE databases and identified 228 eligible studies from 1987 to 2019 which examines both naturally acquired and vaccine induced humoral immunity against HPV infection in female and male subjects from worldwide origin. Herein, we synthesize current knowledge on the features of systemic and mucosal humoral immunity against HPV. We discuss the issues of the balance between the viral clearance or the escape to the host immune response, the differences between natural and vaccine-induced HPV-specific antibodies and their neutralizing capability. We also discuss the protection afforded after natural infection or following prophylactic vaccination.Expert opinion: Understanding the antibody response induced by HPV infection has led to the design of first-generation prophylactic vaccines. Now, prophylactic vaccination induces protective and long-lasting antibody response which would also strengthened the natural moderate humoral response in people previously exposed to the virus.

A Current Update on Human Papillomavirus-Associated Head and Neck Cancers

Human papillomavirus (HPV) infection is the cause of a growing percentage of head and neck cancers (HNC); primarily, a subset of oral squamous cell carcinoma, oropharyngeal squamous cell carcinoma, and laryngeal squamous cell carcinoma. The majority of HPV-associated head and neck cancers (HPV + HNC) are caused by HPV16; additionally, co-factors such as smoking and immunosuppression contribute to the progression of HPV + HNC by interfering with tumor suppressor miRNA and impairing mediators of the immune system. This review summarizes current studies on HPV + HNC, ranging from potential modes of oral transmission of HPV (sexual, self-inoculation, vertical and horizontal transmissions), discrepancy in the distribution of HPV + HNC between anatomical sites in the head and neck region, and to studies showing that HPV vaccines have the potential to protect against oral HPV infection (especially against the HPV types included in the vaccines). The review concludes with a discussion of major challenges in the field and prospects for the future: challenges in diagnosing HPV + HNC at early stages of the disease, measures to reduce discrepancy in the prevalence of HPV + HNC cases between anatomical sites, and suggestions to assess whether fomites/breast milk can transmit HPV to the oral cavity.

Prophylactic human papilloma virus vaccination in head and neck: indications and future perspectives

PURPOSE OF REVIEW

To gain the evidence-based knowledge concerning the efficacy of HPV vaccination for oropharyngeal sites and to highlight the trials and strategies for vaccine administration in HPV-dependent head and neck diseases.

RECENT FINDINGS

Vaccination can be provided in two injections. There is increasing anecdotal evidence that therapeutic vaccination is effective in treatment of recurrent respiratory papillomatosis.

SUMMARY

The availability and broadening spectrum of HPV vaccines make possible the prevention of cervical and other HPV-dependent diseases. Vaccination is now included in the national immunization programs of most industrial countries and will be used, it is hoped, in developing countries within the next few years. In developing countries, few women are screened for cervical precancerous lesions, making immunization even more important. In affluent countries and matured societies, with high coverage of cervical screening, the focus of interest will shift to other HPV-related diseases. The HPV vaccination is effective in preventing oral infection with types targeted by the vaccines.

Salivary HPV DNA informs locoregional disease status in advanced HPV-associated oropharyngeal cancer

OBJECTIVES

Quantifying tumor DNA in tissue and circulating in blood permits high-quality molecular monitoring to detect and track cancer progression. Evaluating tumor DNA in both blood and saliva in human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) could provide a non-invasive and clinically actionable method for real-time disease detection.

METHODS

We previously validated an ultrasensitive droplet-digital (dd)PCR assay targeting the dominant high-risk HPV subtypes causally linked to OPC. Here we enrolled an observational cohort to evaluate the predictive and prognostic potential of paired plasma-salivary tumor DNA among 21 patients with advanced HPV+OPC.

RESULTS

In patients with recurrent, persistent locoregional (LR) disease, median baseline normalized salivary HPV DNA was 10.9 copies/ng total DNA, nearly 20x higher compared with those with distant disease only (p = 0.01). A cutoff of 5 copies/ng yielded 87% sensitivity and 67% specificity for accurately predicting LR disease. Total tumor burden among those with LR disease strongly correlated with salivary HPV DNA levels (R = 0.83, p = 0.02). The rise and fall of salivary HPV DNA predicted treatment failure and response, respectively, in all patients with LR disease, and predated imaging findings. Among paired salivary-plasma (cell-free) cfDNA samples, only higher plasma HPV cfDNA levels were associated with poor outcomes (p < 0.01), suggesting that each bodily fluid provides unique information about HPV disease status.

CONCLUSIONS

Salivary HPV DNA provides valuable information about tumor burden and predicts treatment response in advanced HPV+OPC. Paired blood-saliva samples could be used to monitor HPV DNA with broad applications to inform diagnosis, prognosis, and surveillance in HPV-associated diseases.

Oral testing for high-risk human papillomavirus DNA and E6/E7 messenger RNA in healthy individuals at risk for oral infection

BACKGROUND

Testing for oral high-risk human papillomavirus (HPV) DNA may be useful for identifying individuals at increased risk for HPV-driven oropharyngeal cancer (OPC). However, positivity for HPV DNA provides no information on the transforming potential of the infection. In contrast, the detection of high-risk HPV E6/E7 messenger RNA (mRNA) may help to identify clinically significant infections because of the indispensable role of E6/E7 viral oncoproteins in the carcinogenic process.

METHODS

Oral rinses were collected with a mouthwash from cancer-free individuals at increased risk for oral HPV infection. High-risk HPV DNA and mRNA were evaluated via the testing of the oral rinses with the Linear Array HPV genotyping test and the Aptima HPV assay, respectively.

RESULTS

Overall, 310 subjects with no clinical evidence of lesions of the oral cavity and oropharynx were included in the study. Thirty-three (10.6%) harbored high-risk HPV DNA in their oral rinse. These cases, together with 10 random samples negative for high-risk HPV DNA, were tested with the Aptima assay. A valid result was obtained for 41 of the 43 specimens (95.3%). Among the 31 cases that were positive for high-risk HPV DNA and had a valid Aptima result, 4 (12.9%) were positive for HPV mRNA. HPV mRNA was not detected in any of the samples negative for high-risk HPV DNA.

CONCLUSIONS

HPV mRNA is detectable in oral rinses of cancer-free subjects. Oral HPV mRNA testing may be useful in the screening and/or early detection of HPV-driven OPC by possibly identifying active and transforming oral infections. The testing of individuals at increased risk for HPV-related OPC via simply and noninvasively collected oral specimens is an attractive option for future screening strategies.

Oral immunization with bacteriophage MS2-L2 VLPs protects against oral and genital infection with multiple HPV types associated with head & neck cancers and cervical cancer

Human papillomaviruses (HPVs) are the most common sexually transmitted infections. HPVs are transmitted through anogenital sex or oral sex. Anogenital transmission/infection is associated with anogenital cancers and genital warts while oral transmission/infection is associated with head and neck cancers (HNCs) including recurrent respiratory papillomatosis. Current HPV vaccines protect against HPV types associated with ∼90% of cervical cancers and are expected to protect against a percentage of HNCs. However, only a few studies have assessed the efficacy of current vaccines against oral HPV infections. We had previously developed a mixed MS2-L2 candidate HPV vaccine based on bacteriophage MS2 virus-like particles (VLPs). The mixed MS2-L2 VLPs consisted of a mixture of two MS2-L2 VLPs displaying: i) a concatemer of L2 peptide (epitope 20-31) from HPV31 & L2 peptide (epitope 17-31) from HPV16 and ii) a consensus L2 peptide representing epitope 69-86. The mixed MS2-L2 VLPs neutralized/protected mice against six HPV types associated with ∼87% of cervical cancer. Here, we show that the mixed MS2-L2 VLPs can protect mice against additional HPV types; at the genital region, the VLPs protect against HPV53, 56, 11 and at the oral region, the VLPs protect against HPV16, 35, 39, 52, and 58. Thus, mixed MS2-L2 VLPs protect against eleven oncogenic HPV types associated with ∼95% of cervical cancer. The VLPs also have the potential to protect, orally, against the same oncogenic HPVs, associated with ∼99% of HNCs, including HPV11, which is associated with up to 32% of recurrent respiratory papillomatosis. Moreover, mixed MS2-L2 VLPs are thermostable at room temperature for up to 60 days after spray-freeze drying and they are protective against oral HPV infection.

Sex Differences in Salivary Oxytocin and Cortisol Concentration Changes during Cooking in a Small Group

Background: Oxytocin (OT), a neuropeptide, has positive effects on social and emotional processes during group activities. Because cooking is an integrated process in the cognitive, physical, and socio-emotional areas, cooking in a group is reported to improve emotion and cognition. However, evidence for efficacy in group cooking has not been well established at the biological level. Methods: To address this shortcoming, we first measured salivary levels of OT and cortisol (CORT), a biomarker of psychological stress, before and after group cooking for approximately 1 h by people who know each other in healthy married or unmarried men and women. We then compared the initial OT and CORT concentrations with those during individual non-cooking activities in isolation. Results: Baseline OT concentrations before group and non-group sessions did not significantly differ and OT levels increased after both types of activity in men and women. In men, however, the percentage changes of OT levels in the first over the second saliva samples were significantly small during cooking compared with those in individual activities. In women, however, such a difference was not observed. In contrast, the mean salivary CORT concentrations after group cooking were significantly decreased from the baseline level in both sexes, though such decreases were not significant after individual activity sessions. The sex-specific differences were marital-status independent. Conclusion: These results indicate that OT and CORT concentrations after two activity sessions by a familiar group changed in opposite directions in a sex-specific manner. This suggests that, because cooking is experience-based, we need to consider the sex-specific features of group cooking if we apply it for intervention.