Humoral Immune Response Against Human Papillomavirus as Source of Biomarkers for the Prediction and Detection of Cervical Cancer

The Immune Response Generated against HPV Infection in Men and Its Implications in the Diagnosis of Cancer

Human papillomavirus (HPV) infection is associated with precancerous lesions and cancer of the genital tract both in women and men. The high incidence of cervical cancer worldwide focused the research on this infection mainly in women and to a lesser extent in men. In this review, we summarized epidemiological, immunological, and diagnostic data associated with HPV and cancer in men. We presented an overview of the main characteristics of HPV and infection in men that are associated with different types of cancer but also associated with male infertility. Men are considered important vectors of HPV transmission to women; therefore, identifying the sexual and social behavioral risk factors associated with HPV infection in men is critical to understand the etiology of the disease. It is also essential to describe how the immune response develops in men during HPV infection or when vaccinated, since this knowledge could help to control the viral transmission to women, decreasing the incidence of cervical cancer, but also could reduce other HPV-associated cancers among men who have sex with men (MSM). Finally, we summarized the methods used over time to detect and genotype HPV genomes, as well as some diagnostic tests that use cellular and viral biomarkers that were identified in HPV-related cancers.

Biological, demographic, and health factors associated with HPV infection in Ecuadorian women

Objectives

The study aims to identify the correlation between human papillomavirus (HPV) infection and sociodemographic and sexual reproductive health factors in Ecuadorian women from March to August 2019.

Methods

120 women were randomly selected from two gynecological clinics to complete a questionnaire and provide a biospecimen. PCR-Hybridization was used to genotype 37 HPV serotypes in samples obtained by endo-cervical brushing for liquid-based cytology. Sociodemographic and sexual health data were collected through a validated questionnaire during a medical consultation. Mathematical modeling of HPV infection was done using bivariate logistic regression.

Results

65.0% of the women sampled had an HPV infection; 74.3% of these women had co-infections with other HPV genotypes. Out of the women who were HPV positive, 75.6% were diagnosed with high-risk genotypes from HPV strains 18, 35, 52, and 66. Parity, immunosuppression, and use of oral contraception/intrauterine devices (IUDs) were identified as associated variables. The explanatory model had a sensitivity of 89.5% and a specificity of 73.8%.

Conclusion

The predominant strains of HPV among Ecuadorian women are diverse. The risk of HPV infection is a complex phenomenon where biological and psychosocial variables are integrated into a model. In populations with limited access to health services, low socioeconomic status, and negative sociocultural beliefs about sexually transmitted infections (STIs), surveys can be used as a pre-screening step for HPV infections. The diagnostic value of the model should be tested in multicenter studies that include women from all over the country.

Human Papillomavirus E1 Protein Regulates Gene Expression in Cells Involved in Immune Response

Human papillomavirus belongs to papovaviridae family papillomavirus A, a spherical deoxyribonucleic acid (DNA) virus, which can cause the proliferation of squamous epithelial cells of human skin or mucous membranes. With the rapid increase in the incidence of condyloma acuminatum among STDs and the increase in diseases caused by HPV infection, HPV infection has seriously endangered human health. In this paper, the in vitro detection of HPV E1 protein was realized using AgNCs-dsDNA. And through the test of this detection method, we calculated that the detection limit of this method is 0.886 nM. Compared with other methods for detecting E1 protein in vitro, this method has high sensitivity and simple operation. In addition, the detection method also has good anti-interference and selectivity, and can realize the detection of E1 in serum samples. The transfection efficiency of BLV-miR-B4-3p mimics at different time points was determined by quantitative real-time PCR (qPCR); the transcriptome sequencing of lymphocytes transfected with different concentrations of BLV-miR-B4-3p mimics was performed, and differential gene clustering was performed on the sequencing results. And the BLV-miR-B4-3p target gene prediction and transcriptome analysis results were verified by qPCR. The effects of BLV-miR-B4-3p on the transcriptional levels of immune-related cytokines in human lymphocytes were analyzed. Transcriptome sequencing analysis showed that after BLV-miR-B4-3p entered lymphocytes, a total of 556 differentially expressed genes were obtained. GO enrichment and KEGG analysis results showed that BLV-miR-B4-3p could independently activate influenza. The signaling pathway ultimately affects the body's immune system process, stress response, defense response, immune response, and other biological processes. After BLV-miR-B4-3p enters lymphocytes, it will lead to abnormal lymphocyte immune function, including the mRNA expression of TNF-α in Th1 cytokines which was significantly increased (P < 0.05), and the expression of IL-10 in Th2 cytokines was significantly increased (P < 0.05). The mRNA expression was significantly decreased (P < 0.05), and the mRNA expression of IL-27 was significantly increased (P < 0.001), which did not affect the mRNA expression of lymphocyte proliferation and activation-related regulators. The tumor suppressor breast cancer 1 (BRCA1) and antimicrobial peptide CAMP were significantly increased, and decreased (P < 0.001), and the expression of pro-apoptotic factor Caspase9 showed a significant downward trend (P < 0.05).

Comprehensive analysis of lymph nodes metastasis associated genes in cervical cancer and its significance in treatment and prognosis

Background

Cervical carcinoma is one of the most common malignant tumors of the female reproductive system. Lymph nodes metastasis, the most common metastasis, which can be detected even in small-size tumor patients, results in worse prognosis. Therefore, it is of great significance to explore novel lymph nodes metastasis associated biomarkers, which can predict the prognosis and provide a good reference for clinical decision making in cervical carcinoma patients. However, systematic and comprehensive studies related to the key molecules in lymph node metastasis in cervical carcinoma patients are still absent.

Methods

Transcriptome and clinical data of 307 cervical carcinoma patients were obtained from The Cancer Genome Atlas (TCGA). Then, survival of patients with and without lymph node metastasis was analyzed by Kaplan-Meier (K-M) curves. Differential expressed genes (DEGs) were detected between tumor and control samples using limma package and defined as lymph node metastasis related genes. Univariate and multivariate Cox regression analyses were carried out to screen robust prognostic gene signature. The risk score model and nomogram for predicting survival were constructed based on prognostic gene signature. The performance of the risk score model was evaluated by operating characteristic (ROC) curves. Based on risk score, patients were divided into low- and high- risk groups. DEGs, functional enrichment analysis and tumor microenvironment (immune infiltration and expressions of immune checkpoints) were detected in low- and high-risk groups.

Results

A total of 103 lymph node metastasis-associated genes were identified. Univariate and multivariate Cox regression analyses identified TEKT2, LPIN2, FABP4 and CXCL2 as prognostic gene signature. The risk score model was constructed and validated in cervical carcinoma patients. 345 DEGs identified between high- and low-risk groups were significantly enriched into immune-related biological processes. Furthermore, we found that the immune infiltration and expressions of immune checkpoints were significantly different between low- and high-risk groups.

Conclusion

Our study revealed that lymph node metastasis played an important role in the prognosis of cervical carcinoma patients. Furthermore, we established a risk score model based on lymph node metastasis related genes, which could accurately predict the survival of cervical carcinoma patients. Besides, our findings in tumor microenvironments of low- and high-risk groups improved our understanding of the relationship between lymph node metastasis related genes and cervical carcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08945-8.

Differential Antibody Response against Conformational and Linear Epitopes of the L1 Proteins from Human Papillomavirus Types 16/18 Is Observed in Vaccinated Women or with Uterine Cervical Lesions

Antibodies against the Human Papillomavirus (HPV) L1 protein are associated with past infections and related to the evolution of the disease, whereas antibodies against L1 Virus-Like Particles (VLPs) are used to follow the neutralizing antibody response in vaccinated women. In this study, serum antibodies against conformational (VLPs) and linear epitopes of HPV16/18 L1 protein were assessed to distinguish HPV-vaccinated women from those naturally infected or those with uterine cervical lesions. The VLPs-16/18 were generated in baculovirus, and L1 proteins were obtained from denatured VLPs. Serum antibodies against VLPs and L1 proteins were evaluated by ELISA. The ELISA-VLPs and ELISA-L1 16/18 assays were validated with a vaccinated women group by ROC analysis and the regression analysis to distinguish the different populations of female patients. The anti-VLPs-16/18 and anti-L1-16/18 antibodies effectively detect vaccinated women (AUC = 1.0/0.79, and 0.94/0.84, respectively). The regression analysis showed that anti-VLPs-16/18 and anti-L1-16/18 antibodies were associated with the vaccinated group (OR = 2.11 × 10⁸/16.50 and 536.0/49.2, respectively). However, only the anti-L1-16 antibodies were associated with the high-grade lesions and cervical cancer (CIN3/CC) group (OR = 12.18). In conclusion, our results suggest that anti-VLPs-16/18 antibodies are effective and type-specific to detect HPV-vaccinated women, but anti-L1-16 antibodies better differentiate the CIN3/CC group. However, a larger population study is needed to validate these results.

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.

HPV Induces Changes in Innate Immune and Adhesion Molecule Markers in Cervical Mucosa With Potential Impact on HIV Infection

While most HPV infections are asymptomatic and clear spontaneously, persistent infection with high-risk HPVs is associated with cervical cancer and with increased risk of HIV acquisition. Although several hypotheses have been proposed to explain this phenomenon, none has been confirmed. Our aim was to investigate the expression of host factors involved in the susceptibility to HIV infection among HPV-infected women. Cervical samples were collected to characterize the expression levels of HIV susceptibility markers in the mucosa of HPV-infected compared with HPV-uninfected women. No differences in the frequency of CCR5+, integrin α4β7+, activated and memory CD4+ T-cell were detected between the groups. We additionally evaluated the expression levels of genes involved in innate immune responses and in cell adhesion. HPV infected patients expressed higher levels of TLR9 and lower levels of pattern recognition receptors that recognize RNA (TLR3, TLR7, and MDA5/IFIH1). We also detected an impaired IFN pathway, with an increased Type I IFN and a decreased IFNα2 receptor expression. HPV+ samples displayed reduced expression of genes for adherens and tight junctions. Taken together, these results suggest that although HPV infection does not result in the recruitment/activation of susceptible CD4+ T-cell in the female genital tract, it leads to changes in the innate antiviral immune responses and in cell adhesion that are likely to favor HIV infection.

Expression of different L1 isoforms of Mastomys natalensis papillomavirus as mechanism to circumvent adaptive immunity

Although many high-risk mucosal and cutaneous human papillomaviruses (HPVs) theoretically have the potential to synthesize L1 isoforms differing in length, previous seroepidemiological studies only focused on the short L1 variants, co-assembling with L2 to infectious virions. Using the multimammate mouse Mastomys coucha as preclinical model, this is the first study demonstrating seroconversion against different L1 isoforms during the natural course of papillomavirus infection. Intriguingly, positivity with the cutaneous MnPV was accompanied by a strong seroresponse against a longer L1 isoform, but to our surprise, the raised antibodies were non-neutralizing. Only after a delay of around 4 months, protecting antibodies against the short L1 appeared, enabling the virus to successfully establish an infection. This argues for a novel humoral immune escape mechanism that may also have important implications on the interpretation of epidemiological data in terms of seropositivity and protection of PV infections in general.

Prevalence, genotype distribution and risk factors of cervical HPV infection in Yangqu, China: a population-based survey of 10086 women

Human papillomavirus(HPV) infection is a necessary factor for the development of cervical cancer. The HPV vaccine is currently available, but there is still a lack of large-scale research on the distribution and risk factors of HPV. The aim of this study is to investigate the genotype distribution and risk factors of HPV infection in Yangqu which is located in North China. This study enrolled 10086 women aged <65 years from Yangqu County. HPV genotypes were identified via standard HPV DNA testing. The overall prevalence of HPV infection was 8.92%. The prevalence of high-risk HPV types was 8.80%, and it was 0.38% for low-risk HPV types. Single genotype infection accounted for 67.91% in HPV-positive cases. The most common HPV genotypes were HPV-16, -52, and -58. HPV-18 was only the 11th most common type in HPV-positive cases. Women ≥50 years of age had the highest prevalence rate of HPV, and women <30 years had the lowest prevalence rate. The distribution of HPV genotypes also varied among the three age groups: <30, 30-49, and ≥50 years. The risk factors that contributed to the rate of HPV infection included low educational level, low income, smoking, age at first sexual encounter <23 years old, and number of births ≥3 times. This large routine clinical practice report of HPV prevalence and genotype distribution revealed the characteristics of HPV infection-type distributions in Shanxi Province, which should be considered in formulating comprehensive prevention strategies including vaccination for cervical cancer in China.

The value of cytokine levels in triage and risk prediction for women with persistent high-risk human papilloma virus infection of the cervix

Background

Cervical cancer is a common cancer among women worldwide and is closely related to high-risk human papillomavirus infection (HR-HPV). The immune microenvironment is thought to play an essential role in viral infection and cancer development; however, this relationship remains controversial. Cytokines are an important part of the immune system. Therefore, in this study, we explored changes in cervical cytokine levels of women with persistent HR-HPV infection and determined the value of cytokine detection in assessing cervical lesions.

Methods

We enrolled 146 patients; 117 had long-term high-risk (HR) HPV infection (> 6 months), and 29 were HPV-negative with previous HR-HPV infection. According to histopathological examination, 43 patients were diagnosed with cervicitis; 35, with low-grade squamous intraepithelial lesions (LSILs); and 39, with high-grade squamous intraepithelial lesions (HSILs). Cytokine levels in vaginal fluid were examined using cytometric bead array, and the values of interleukin (IL)-6 and IL-2 levels were converted to a cytokine score. The performance of the cytokine score for diagnosis and risk assessment was compared with that of ThinPrep cytology tests (TCTs).

Results

Disease severity was positively associated with IL-6 levels and inversely related to IL-2 levels. The area under the curve (AUC) was higher for the cytokine score including IL-6 and IL-2 than for TCTs for HSILs. Comparisons of the sensitivity, specificity, Youden index, and positive and negative predictive values for HSILs demonstrated that the cytokine score was better than TCT. HPV-positive patients with high cytokine scores showed increased risk of developing HSIL within 3 years. The hazard ratio for the cytokine score was 3.12; thus, the risk of developing HSIL was related to the cytokine score.

Conclusions

The cytokine score increased with the severity of cervical lesions and could distinguish more patients from HPV-positive women and predict the risk of disease progression.

Profiling of serum antibodies against human papillomavirus antigens in Korean women with cervical intraepithelial neoplasia and cervical cancer

Sero-epidemiological studies of human papillomavirus (HPV) have been undertaken over the last two decades. In this study, the prevalences of nine serum antibodies (anti-E6, E7 and L1 antibodies of HPV types 16, 18, and 58) were evaluated in normal (control) Korean women and women with cervical intraepithelial neoplasia (CIN) I, CIN II, CIN III, and cervical cancer. The frequencies of all types of anti-HPV antibodies were higher in the CIN stages and cervical cancer than in normal women, and those of anti-HPV16 E6 and E7, anti-HPV18 E6 and E7, and anti-HPV58 E7 antibodies were higher in the cervical cancer group than in the CIN stages. The frequencies of antibodies against HPV16, 18, and 58 E7 tended to increase with increasing severity of cervical lesions. However, there were few differences in the frequencies of antibodies against the L1 antigens of HPV16, 18 and 58 in cervical cancer versus CIN stages. The anti-HPV antibodies were detected in 26.5% of normal, 46.3% of CIN I, 62.5% of CIN II, 51.6% of CIN III, and 75% of cancers when any of the nine antigens was used as a criterion. Correlations between HPV DNA positivity and seropositivity for anti-HPV E6, E7, or L1 antibodies were found only in HPV16 DNA-positive cervical cancers for anti-HPV16 E6 and L1 antibodies. In addition, strong positive correlations in seropositivity were found between anti-HPV16 E7 and anti-HPV58 E7 antibodies, and between anti-HPV18 E6 and anti-HPV58 E6 antibodies. These findings should advance global profiling of the seroprevalences of antibodies against HPV antigens.

Development of podophyllotoxin‑loaded nanostructured lipid carriers for the treatment of condyloma acuminatum

Condyloma acuminatum (CA) is a common sexually transmitted disease caused by human papillomavirus (HPV). Podophyllotoxin (POD), a cytotoxic compound, is able to effectively treat HPV; however, the severe irritation side effects of POD restrict its use as a treatment for CA. The aim of the present study was to construct novel POD‑loaded nanostructured nanolipid carriers (POD‑NLCs) and evaluate their physicochemical characteristics and cytotoxicity. POD‑NLCs (0.5%) were prepared using emulsion‑evaporation and low temperature‑solidification methods with optimized conditions and preparations. Subsequently, the POD‑NLCs were physicochemically characterized and their in vitro and in vivo release efficiencies and in vitro cytotoxicity were studied. The prepared POD‑NLCs had an average particle size, ζ potential, polydispersity index and encapsulation efficacy of 178.5±20 nm, ‑27±0.5 mV, 0.18±0.01 and 82.9±2%, respectively. In vitro and in vivo release studies demonstrated that POD‑NLCs are able to provide sustained drug delivery for 72 h in vitro and 10 h in the mucosa. Compared with a tincture formulation of POD (POD‑T), POD‑NLC induced less inflammatory cytokine production in the cervical mucous and led to a decreased histopathological score. In addition, a cytotoxicity assay demonstrated that inhibition of the POD‑NLCs was 98.4% at 24 h and remained >98% up to 72 h. Furthermore, more cells were arrested in the G2/M phase of the cell cycle following POD‑NLC treatment compared with the POD‑T treatment. The present study provides evidence that POD‑NLC is a promising delivery system for the treatment of CA.

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.

Tumour-inducing viruses

Virus infections are an important factor in the global burden of human cancer. The discovery and mode of action of human tumour viruses is briefly reviewed together with the promise of prevention through vaccination.

Triage of high-risk HPV positive women in cervical cancer screening

INTRODUCTION

High-risk human papillomavirus (hrHPV) testing is expected to replace cytology as primary screening method for cervical cancer screening in an increasing number of countries. The high sensitivity of hrHPV testing is combined with a limited specificity which makes triaging of hrHPV positive women necessary. As an ideal triage method does not yet exist, an optimal triage strategy for hrHPV positive women based on current knowledge should be obtained. The aim of this article is to present an overview of available options for triage of hrHPV positive women, with their strengths and limitations and possible future opportunities.

AREAS COVERED

Current knowledge on morphological biomarkers, molecular biomarkers and combined triage strategies will be discussed to give an overview of the state-of-the-art on triaging hrHPV positive women. The literature search was limited to studies on triage strategies for hrHPV positive women. Expert commentary: Experience with morphology-based biomarkers makes these a valuable triage method. However, they lack the ability of differentiating productive from transforming infections. Molecular biomarkers are objective, highly reproducible, can be used in high throughput testing, and show promising results. With more extensive knowledge on these molecular markers, cervical cancer screening may transform to a full molecular screening in the future.