Naturally acquired HPV antibodies against subsequent homotypic infection: A large-scale prospective cohort study

Immunogenicity of the 9-valent human papillomavirus vaccine: Post hoc analysis from five phase 3 studies

Post hoc analyses of 9-valent human papillomavirus (9vHPV) vaccine immunogenicity were conducted in five Phase 3 studies that enrolled males. Month 7 antibody geometric mean titers (GMTs) after three 9vHPV vaccine doses were analyzed in 10,024 males/females aged 16-26 years from studies 001 (NCT00543543), 002 (NCT00943722), 003 (NCT01651949), and 020 (NCT02114385). Covariates considered were age, gender, sexual orientation, region of residence, and race. GMTs among 2599 males/females aged 9-15 years (studies 002 and 010 [NCT01984697]) were assessed 6 months after one, two, and three 9vHPV vaccine doses. 9vHPV vaccine immunogenicity was robust across populations. Month 7 GMTs were generally higher in participants aged 16-21 versus 22-26 years. Region and race minimally impacted immunogenicity. Adjusted integrated analysis showed lower immunogenicity in men who have sex with men (MSM) versus heterosexual men (HM) for nine HPV types, and higher immunogenicity in HM versus females for seven HPV types. Among 9-15-year-olds, trends toward higher GMTs in males versus females post-Dose 3, similar GMTs post-Dose 2, and lower post-Dose 1 were observed. In conclusion, 9vHPV vaccine immunogenicity was robust in males aged 16-26 years across a range of baseline characteristics. GMT ratios for males versus females aged 9-15 years tended to increase with more doses.

Mir-615-5p inhibits cervical cancer progression by targeting TMIGD2

BACKGROUND

Cervical cancer (CC) is a prevalent gynecological malignancy, contributing to a substantial number of fatalities among women. MicroRNAs (miRNAs) have emerged as promising biomarkers with significant potential for the early detection and prognosis of CC.

OBJECTIVE

This study aimed to explore the clinical significance and biological role of miR-615-5p in CC, with the goal of identifying novel biomarkers for this disease.

MATERIALS AND METHODS

The levels of miR-615-5p and TMIGD2 mRNA in tissue samples and cells were quantified through quantitative reverse transcription real-time PCR, followed by statistical analyses to investigate the correlation between miR-615-5p and clinical data. The effects of miR-615-5p on the proliferation and metastasis of CC cells were evaluated using the Cell Counting Kit-8 and Transwell assays. The potential mechanism of miR-615-5p was elucidated by bioinformatics analyses and Dual-luciferase reporter assay. Western blotting was employed to measure the protein levels of TMIGD2.

RESULTS

In CC, the downregulation of miR-615-5p was related to poor prognosis and emerged as an independent prognostic factor. The levels of miR-615-5p were reduced in CC cells. miR-615-5p overexpression restrained the proliferation and metastasis of CC cells. Furthermore, TMIGD2 was identified as a target gene regulated by miR-615-5p, and its expression was notably elevated in CC. The influence of miR-615-5p on the biological behaviors of CC cells was mediated through the modulation of TMIGD2.

CONCLUSIONS

Downregulation of miR-615-5p was a prognostic indicator of poor prognosis in CC. miR-615-5p exerted its tumor-suppressive effects by inhibiting cell growth and metastasis through the regulation of TMIGD2.

Naturally Acquired Genotype-Specific HPV Seroreactivity and Subsequent HPV Detection Among Heterosexual Partners

The protective effect of naturally acquired humoral immunity against human papillomavirus (HPV) infection remains unclear. To investigate the role of infection-induced antibodies on HPV detection in heterosexual partners, we used data from 392 unvaccinated couples (females aged 18-25 years attended up to six visits over 2 years; males aged 17-37 years attended up to two visits 4 months apart) enrolled (2005-2011) in Montreal. Genital and blood samples were HPV DNA genotyped and tested for L1 antibody titers of 14 HPV genotypes. Analyses considered female-HPV units (n = 4914 based on 351 couples) and male-HPV units (n = 4214 based on 301 couples); each female and male, respectively, contributed up to 14 observations corresponding to 14 genotypes. Modified Cox and logistic regressions estimated hazard and odds ratios (HR/OR) and 95% confidence intervals (CIs) for genotype-specific HPV detections by partner serostatus (high/low: ≥/< baseline median antibody titers, 392 couples). There were 919 and 231 cumulative HPV detections among female-HPV and male-HPV units, respectively. Risk of HPV detections in females (HR = 1.05, CI: 0.90-1.22) and males (OR = 1.31, CI: 0.97-1.77) was similar between those with partners of high versus low serostatus. Constraining to baseline HPV-negative participants with HPV-positive partners yielded unchanged results. This lack of association suggests that naturally developed HPV antibodies do not protect sexual partners from infection.

WHO International Standards for antibodies to HPV6 HPV11 HPV31 HPV33 HPV45 HPV52 and HPV58

Previously established World Health Organization (WHO) International Standards (IS) for anti-HPV16 and HPV18 antibodies are used to harmonize results across human papillomavirus (HPV) serology assays. Here, we present an international collaborative study to establish ISs for antibodies against HPV6 (NIBSC code 19/298), HPV11 (20/174), HPV31 (20/176), HPV33 (19/290), HPV45 (20/178), HPV52 (19/296) and HPV58 (19/300). The candidate standards were prepared using sera from naturally infected individuals. Each candidate was shown to be monospecific for reactivity against its indicated HPV type except for the HPV11 candidate, which was also reactive against other types. Expression of antibody levels relative to the relevant candidate IS reduced inter-laboratory variation allowing greater comparability between laboratories. Based on these results, the WHO Expert Committee on Biological Standardization established each of the 7 candidates as the 1st IS for antiserum to its indicated HPV type for use in the standardization of HPV pseudovirion-based neutralization and antibody-binding assays.

Naturally developed HPV16 antibodies and risk of newly detected cervical HPV infection outcomes

Little is known about the protection conferred by antibodies from natural human papillomavirus (HPV) infection. Our objective was to evaluate the association between HPV16 seroreactivity and HPV16 redetection, newly detected HPV infections, and loss of HPV DNA detection during follow-up. We analyzed data from 2462 unvaccinated Brazilian women. HPV16 IgG and neutralizing antibodies at baseline were assessed by enzyme-linked immunosorbent assay (n = 1975) and by the pseudovirus-based papillomavirus neutralization assay (n = 487). HPV detection, genotyping, and viral load were assessed by PCR-based methods. The associations were analyzed by Cox proportional hazards models. We observed a positive association between HPV16 IgG seroreactivity and redetection of HPV16 infections. Age-adjusted hazard ratios (HR) with 95% confidence intervals (CI) ranged from 2.45 (1.04-5.74) to 5.10 (1.37-19.00). Positive associations were also observed between HPV16 IgG antibodies and (1) newly detected HPV infections by genotypes unrelated to HPV16 (age-adjusted HR [95% CI] = 1.32 [1.08-1.2]) and (2) loss of detection of HPV infections by genotypes unrelated to HPV16 (age-adjusted HR [95% CI] = 1.24 [1.03-1.50]). Naturally developed HPV16 antibodies do not prevent recurrent HPV infections. Overall HPV16 IgG and neutralizing antibodies seem to be serological markers for latent or past infections.

Global evaluation of lineage-specific human papillomavirus capsid antigenicity using antibodies elicited by natural infection

Human Papillomavirus (HPV) type variants have been classified into lineages and sublineages based upon their whole genome sequence. Here we have examined the specificity of antibodies generated following natural infection with lineage variants of oncogenic types (HPV16, 18, 31, 33, 45, 52 and 58) by testing serum samples assembled from existing archives from women residing in Africa, The Americas, Asia or Europe against representative lineage-specific pseudoviruses for each genotype. We have subjected the resulting neutralizing antibody data to antigenic clustering methods and created relational antigenic profiles for each genotype to inform the delineation of lineage-specific serotypes. For most genotypes, there was evidence of differential recognition of lineage-specific antigens and in some cases of a sufficient magnitude to suggest that some lineages should be considered antigenically distinct within their respective genotypes. These data provide compelling evidence for a degree of lineage specificity within the humoral immune response following natural infection with oncogenic HPV.

Association of naturally acquired type-specific HPV antibodies and subsequent HPV re-detection: systematic review and meta-analysis

BACKGROUND

Understanding the role of naturally acquired (i.e., infection-induced) human papillomavirus (HPV) antibodies against reinfection is important given the high incidence of this sexually transmitted infection. However, the protective effect of naturally acquired antibodies in terms of the level of protection, duration, and differential effect by sex remains incompletely understood. We conducted a systematic review and a meta-analysis to (1) strengthen the evidence on the association between HPV antibodies acquired through past infection and subsequent type-specific HPV detection, (2) investigate the potential influence of type-specific HPV antibody levels, and (3) assess differential effects by HIV status.

METHODS

We searched Embase and Medline databases to identify studies which prospectively assessed the risk of type-specific HPV detection by baseline homologous HPV serostatus among unvaccinated individuals. Random-effect models were used to pool the measures of association of naturally acquired HPV antibodies against subsequent incident detection and persistent HPV positivity. Sources of heterogeneity for each type were assessed through subgroup analyses stratified by sex, anatomical site of infection, male sexual orientation, age group, and length of follow-up period. Evidence of a dose-response relationship of the association between levels of baseline HPV antibodies and type-specific HPV detection was assessed. Finally, we pooled estimates from publications reporting associations between HPV serostatus and type-specific HPV detection by baseline HIV status.

RESULTS

We identified 26 publications (16 independent studies, with 62,363 participants) reporting associations between baseline HPV serostatus and incident HPV detection, mainly for HPV-16 and HPV-18, the most detected HPV type. We found evidence of protective effects of baseline HPV seropositivity and subsequent detection of HPV DNA (0.70, 95% CI 0.61-0.80, NE = 11) and persistent HPV positivity (0.65, 95% CI 0.42-1.01, NE = 5) mainly for HPV-16 among females, but not among males, nor for HPV-18. Estimates from 8 studies suggested a negative dose-response relationship between HPV antibody level and subsequent detection among females. Finally, we did not observe any differential effect by baseline HIV status due to the limited number of studies available.

CONCLUSION

We did not find evidence that naturally acquired HPV antibodies protect against subsequent HPV positivity in males and provide only modest protection among females for HPV-16. One potential limitation to the interpretation of these findings is potential misclassification biases due to different causes.

Long-Term immunopersistence and safety of the Escherichia coli-produced HPV-16/18 bivalent vaccine in Chinese adolescent girls

The study assessed long-term immunopersistence and safety of the Escherichia coli (E. coli)-produced HPV-16/18 bivalent vaccine. In total, 979 participants in the initial immunogenicity noninferiority study, including girls aged 9-14 years who were randomized in a 1:1 ratio to receive 2 doses at months 0 and 6 (n = 301) or 3 doses at months 0, 1 and 6 (n = 304); girls aged 15-17 years (n = 149) and women aged 18-26 years (n = 225) who received 3 doses of the vaccine, were invited to participate in follow-up to 30 months post vaccination (NCT03206255). Serum samples were collected at months 18 and 30, and anti-HPV-16/18 IgG antibodies were measured by enzyme-linked immunosorbent assay. Serious adverse events (SAEs) occurred from month 7 through month 30 were recorded. At month 30, in the per-protocol set, all participants remained seropositive, except for one girl in the 9-14 years (2 doses) group who seroconverted to negative for HPV-18. HPV-16 and HPV-18 antibody levels were higher in girls aged 9-17 years who received 3 doses (125.3 and 60.2 IU/ml) than in women aged 18-26 years who received 3 doses (72.6 and 28.3 IU/ml), and those in girls aged 9-14 years who received 2 doses (73.2 and 24.9 IU/ml) were comparable to those in women aged 18-26 years who received 3 doses. No SAEs were reported to be causally related to vaccination. The E. coli-produced bivalent HPV-16/18 vaccine is safe and induces persistent protective antibodies for up to 30 months after vaccination in girls aged 9-17 years receiving 2 or 3 doses.

Comparison of HPV neutralizing and IgG antibodies in unvaccinated female adolescents

Aims: To analyze the consistency between HPV neutralizing antibodies and specific total IgG antibodies in unvaccinated females. Materials & methods: Serum samples from 978 unvaccinated Chinese females aged 9-26 years were measured for antibodies against HPV-16 and HPV-18 using simultaneous pseudovirus-based neutralization assay and ELISA. Results: There was a moderate level of consistency between HPV neutralizing antibodies and specific IgG in females aged 18-26 years (Cohen's κ coefficient for HPV-16 and HPV-18: 0.52 and 0.38) and poor consistency in those aged 9-17 years (Cohen's κ coefficient <0.05). However, Cohen's κ coefficient remained almost unchanged in sensitivity analysis when the IgG antibody cut-off value was raised. Conclusion: HPV neutralizing antibodies are a more specific indicator for the evaluation of HPV natural humoral immunity.