Epidemiologic and mucosal immunologic aspects of HPV infection and HPV-related cervical neoplasia in the lower female genital tract: a review

Twenty years of research on HPV vaccines based on genetically modified lactic acid bacteria: an overview on the gut-vagina axis

Most cervical cancer (CxCa) are related to persistent infection with high-risk human papillomavirus (HR-HPV) in the cervical mucosa, suggesting that an induction of mucosal cell-mediated immunity against HR-HPV oncoproteins can be a promising strategy to fight HPV-associated CxCa. From this perspective, many pre-clinical and clinical trials have proved the potential of lactic acid bacteria (LAB) genetically modified to deliver recombinant antigens to induce mucosal, humoral and cellular immunity in the host. Altogether, the outcomes of these studies suggest that there are several key factors to consider that may offer guidance on improvement protein yield and improving immune response. Overall, these findings showed that oral LAB-based mucosal HPV vaccines expressing inducible surface-anchored antigens display a higher potential to induce particularly specific systemic and mucosal cytotoxic cellular immune responses. In this review, we describe all LAB-based HPV vaccine investigations by reviewing databases from international studies between 2000 and 2020. Our aim is to promote the therapeutic HPV vaccines knowledge and to complete the gaps in this field to empower scientists worldwide to make proper decisions regarding the best strategies for the development of therapeutic HPV vaccines.

Analysis of the efficacy of liquid-based cytology combined with HPV genotypes in screening cervical lesions in women of different ages

Objectives

To evaluate the value of liquid-based cell examination combined with human papillomavirus (HPV) genotypes in the detection of cervical intraepithelial neoplasia.

Methods

A total of 21,155 patients who had undergone cytology, HPV genotypes and colposcopy-guided biopsy were grouped into three groups. Sensitivity, specificity, positive predictive value, and negative predictive value of the test methods of the three groups were compared.

Results

In the age group of less than 50 years, the sensitivity of HPV genotype testing was significantly higher than that of liquid-based cytology. The specificity of liquid-based cytology was significantly higher in all age groups than that of HPV genotype testing. The positive predictive value of each test index was higher in the age group less than 30 years, and the negative predictive value was higher in the 30–50-year age groups. In different age groups, liquid-based cytology and HPV genotype combined method can improve the sensitivity of detection and negative predictive values.

Conclusions

The HPV test has higher sensitivity and negative predictive value, and the cytology method is relatively specific and less sensitive. The combined method has better sensitivity and negative predictive value.

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.

Human Papillomavirus Infection in Patients with Residual or Recurrent Cervical Intraepithelial Neoplasia

Aims and background

The main purpose of this longitudinal study was to evaluate the frequency of HPV infection in patients with residual or recurrent CIN.

Methods

797 consecutive patients with CIN, treated with conization, were included. In 38 patients with residual or recurrent CIN in whom reconization was performed, infection with high-risk HPV types was analyzed.

Results

Reconization was performed in 4.8% of patients. Before reconization, 21 patients (55.3%) were infected with high-risk HPV and 17 patients (44.7%) were HPV negative. Among the HPV-negative patients, two (11.8%) had CIN 1, five (29.4%) CIN 2, nine (52.9%) CIN 3 and one patient (5.9%) had microinvasive cancer of the uterine cervix. The difference in frequency of infection with high-risk HPV was not significant (chi-square 0.372; p>0.05).

Conclusions

On the basis of the study results it is not possible to recommend the HPV test as the only method of detection of residual or recurrent CIN after conization.

Prognostic significance of immunohistochemical phenotypes in patients treated for high-grade cervical intraepithelial neoplasia

Strong evidence exists that the host's immune system plays a crucial role for the development of human papillomavirus-related cervical premalignant and malignant lesions. In particular, effective cell-mediated immunity (CMI) promotes spontaneous infection clearance and cancer precursors regression in healthy subjects, while immunosuppressed individuals are more likely to experience infection persistence, cervical intraepithelial neoplasia (CIN) lesions, and cervical cancer. In this study, the prognostic significance of immunohistochemical profiling of CD4+ T-cells, CD8+ T-cells, dendritic cells (CD11c+), T-bet+, and GATA-3+ transcription factors has been studied in surgical specimens of 34 consecutive women affected by high-grade cervical intraepithelial neoplasia (CIN2-3) submitted to cervical conization. Results have been correlated with the clinical outcomes at 24 months after treatment and statistically analyzed. Higher rates of CD4+ T-cells, CD11c+ dendritic cells, and T-bet+ transcription factor positivity showed a strong statistically significative correlation with favourable clinical outcomes (P ≤ 0.0001). These data reinforce the evidence of the relevance of the host's immune status in the natural history of HPV-related cervical disease and add a prognostic significance of the cervical immunological profile in terms of predicting significant lower recurrence rates.

TP53 codon 72 polymorphism and risk of cervical carcinoma in Serbian women

PURPOSE

It was shown that individuals homozygous for the Arg-encoding allele of codon 72 TP53 gene may have an increased risk to human papillomavirus (HPV)-related cervical carcinomas. However, many studies have failed to confirm this hypothesis. The aim of this study was to investigate a role of the TP53 codon 72 polymorphism in cervical carcinoma development in Serbian women.

METHODS

In comparative, prospective study, we analyzed 49 wild type TP53 gene cervical carcinomas samples and 74 cervical smears of gynecologically healthy women. DNA was extracted by salting-out procedure. Codon 72 polymorphism was assessed by Restriction Fragment-Length Polymorphism method. Presence of HPV infection was detected through amplification of one part of L1 viral gene. χ(2) and odds ratio were used for statistical analysis.

RESULTS

The distribution of Arg/Arg, Arg/Pro, and Pro/Pro genotypes of codon 72 of TP53 gene was: 63.3, 34.7, and 2.0 % in the cervical carcinomas and 58.1, 33.8, and 8.1 % in the control group. We observed an increased risk for the development of cervical carcinoma for Arg homozygotes in relation to heterozygotes plus Pro homozygotes (OR 1.24; 95 % CI 0.59-2.61) and higher one for Arg/Arg plus Arg/Pro genotype in relation to Pro homozygotes (OR 4.24; 95 % CI 0.49-36.32).

CONCLUSIONS

The results indicate that carriers of Arg allele of codon 72 TP53 gene have an increased risk for development of cervical carcinoma in Serbian women. However, the influence is not statistically significant and requires analysis of larger case-control group.

Interactions of sexual activity, gender, and depression with immunity

INTRODUCTION

Depression can suppress immune function, leading to lower resistance against infection and longer healing times in depressed individuals. Sexuality may also influence immune function, with evidence that sexual activity is associated with lowered immune function in women and mixed results in men. Immune mediators like immunoglobulin A (IgA) are immediately relevant to sexual health, since they are the first line of defense against pathogens at mucous membranes like the vagina.

AIM

This study aims to determine if and how depression, sexual activity, and their interaction impact salivary IgA (SIgA) in men and women.

METHODS

In Study 1, a community-based sample of 84 women and 88 men provided saliva samples and completed questionnaires on their demographic background, level of depression, and frequency of partnered and solitary sexual activity. Study 2, conducted separately in an undergraduate student sample of 54 women and 52 men, had similar methods.

MAIN OUTCOME MEASURES

The main outcome measures were scores on the General Well-Being Schedule depression subscale, reported frequency of sexual activity, and SIgA levels as measured by enzyme immunoassay.

RESULTS

Across studies, higher levels of partnered sexual activity were associated with lower SIgA for women with high depression scores, but not for women with low depression scores. In contrast, higher levels of partnered sexual activity were associated with higher SIgA for men with high depression scores, but not for men with low depression scores.

CONCLUSION

Our results show that partnered sexual activity is a risk factor for lowered immunity in women with depressive symptoms but a possible resilience factor for men with depressive symptoms. This suggests a role for sexual activity in determining the impact of depression on physical health parameters.

Human papillomavirus's physical state and cyclin A1 promoter methylation in cervical cancer

BACKGROUND

Cervical cancer is the second biggest cause of death among human female cancers. Human papillomavirus (HPV) is the main factor in this cancer, especially HPV types 16 and 18, which constitute the high-risk group. There are 2 physical states of HPV in host cells: integrated and episomal forms. Our previous study explored the very high degree of cyclin A1 (CCNA1) promoter methylation in invasive cervical cancer in which all cases were infected by HPV.

OBJECTIVE

From previous evidence, it seemed that HPV might affect CCNA1 promoter methylation. Therefore, both the quantity and physical state of HPV were investigated in this study for their effects on CCNA1 promoter methylation.

MATERIALS AND METHODS

To determine the correlation of HPV quantity and CCNA1 methylation, the proportion of HPV L1/HAT (histone acetyltransferase, which is a human housekeeping gene) and the percentage intensity of CCNA1 promoter methylation were observed. CCNA1 promoter methylation was detected by methylation-specific primer polymerase chain reaction. To investigate the physical state, the HPV E2 region was amplified. The effect of the physical state on CCNA1 methylation was observed.

RESULTS

No correlation was found between the quantity of HPV and CCNA1 promoter methylation. Interestingly, the physical state of HPV had the potential to affect methylation of this gene. The integrated form of HPV had a significantly higher impact on CCNA1 methylation than HPV in episomal form (P=0.001; 95% confidence interval, 11.96-38.44).

CONCLUSION

We suggest that the integrated form of HPV might lead to CCNA1 promoter methylation in cervical cancer by some mechanisms.

Human papillomavirus type 16 E6-specific antitumor immunity is induced by oral administration of HPV16 E6-expressing Lactobacillus casei in C57BL/6 mice

Given that local cell-mediated immunity (CMI) against the human papillomavirus type 16 E6 (HPV16 E6) protein is important for eradication of HPV16 E6-expressing cancer cells in the cervical mucosa, the HPV16 E6 protein may be a target for the mucosal immunotherapy of cervical cancer. Here, we expressed the HPV16 E6 antigen on Lactobacillus casei (L. casei) and investigated E6-specific CMI following oral administration of the L. casei-PgsA-E6 to mice. Surface expression of HPV16 E6 antigens was confirmed and mice were orally inoculated with the L. casei-PgsA or the L. casei-PgsA-E6. Compared to the L. casei-PgsA-treated mice, significantly higher levels of serum IgG and mucosal IgA were observed in L. casei-PgsA-E6-immunized mice; these differences were significantly enhanced after boost. Consistent with this, systemic and local CMI were significantly increased after the boost, as shown by increased counts of IFN-γ-secreting cells in splenocytes, mesenteric lymph nodes (MLN), and vaginal samples. Furthermore, in the TC-1 tumor model, animals receiving the orally administered L. casei-PgsA-E6 showed reduced tumor size and increased survival rate versus mice receiving control (L. casei-PgsA) immunization. We also found that L. casei-PgsA-E6-induced antitumor effect was decreased by in vivo depletion of CD4⁺ or CD8⁺ T cells. Collectively, these results indicate that the oral administration of lactobacilli bearing the surface-displayed E6 protein induces T cell-mediated cellular immunity and antitumor effects in mice.

The effect of cigarette smoking on cervical langerhans cells and T and B lymphocytes in normal uterine cervix epithelium

The objective of our study was to evaluate the effect of smoking on intraepithelial Langerhans cells and T and B lymphocytes in normal cervical epithelium. A total of 47 women who underwent hysterectomies because of uterine leiomyomata were investigated. Thirty-two individuals were nonsmokers and 15 were current smokers. A segment of tissue was taken from the cervix after the removal of the uterus and was formalin-fixed and paraffin-embedded for histologic analysis. The identification of the Langerhans cells and T and B lymphocytes was carried out by immunohistochemical analysis. The number of intraepithelial Langerhans cells was expressed by the amount of cells per square millimeter of epithelium. For T and B lymphocytes, a score expressed the cell count. The comparison of the number of intraepithelial Langerhans cells between smoking and nonsmoking women showed a significant difference (P=0.045), but it did not occur in relation to the number of T and B cells between the 2 groups. There was also no significant difference in relation to the number of cigarettes smoked per day, time of consumption, and total amount of cigarettes smoked throughout the lifetime. It was shown that smoking reduces the number of intraepithelial Langerhans cells in a normal cervix but does not influence the number of T and B lymphocytes.

Immunohistochemical and ultrastructural features of Langerhans cells in condyloma acuminatum

BACKGROUND

There are few studies on the abnormal morphology of Langerhans cells (LCs) in condyloma acuminatum (CA) lesions and the essence of the abnormal morphology of LCs in CA lesions is still not well elucidated. The aim of this study was to further investigate the morphological features of LCs in CA lesions.

METHODS

CD1a(+) LCs in 13 CA lesions and in 13 normal controls were labeled using immunohistochemistry and examined by light microscopy. Ultrastructural investigation on LCs in six CA lesions and in six normal controls was performed by electron microscopy.

RESULTS

Compared with those in normal controls, most CD1a(+) LCs in CA lesions exhibited dysplastic dendrities and abnormal distribution. The number of CD1a(+) LCs in CA lesions (26.31 +/- 18.84) was statistically lower (p < 0.001) than that in normal controls (72.00 +/- 27.40). Electron microscopy showed that the number of Birbeck granules within lesional LCs (4.00 +/- 2.94) was significantly decreased (p < 0.001) than that within normal LCs (10.80 +/- 4.78). The ultrastructures of most lesional LCs displayed degenerative changes.

CONCLUSIONS

The morphology of most LCs in CA lesions shows degenerative changes, which suggest that these LCs have been functionally impaired.

Correlation between laminin-5 immunohistochemistry and human papillomavirus status in squamous cervical carcinoma

BACKGROUND

Human papillomavirus (HPV) plays a critical role in the carcinogenesis of squamous cervical carcinoma. Integration of viral DNA into the host genome is a major contributing factor to malignant transformation. Viral load may influence integration.

AIMS

To compare HPV status (type, viral load, integration status) between normal samples, carcinoma in situ and invasive carcinoma in order to elucidate the role of HPV in progression to invasive lesions.

METHODS

The study population comprised 10 biopsy samples from each diagnostic group. Laminin-5 immunohistochemistry was performed to distinguish invasive carcinoma from non-invasive high-grade lesions. Real-time PCR was used to detect specific HPV types, viral load and integrated HPV, with quantification of viral E2 and E6 genes.

RESULTS

Invasive carcinomas contained a higher number of laminin-5 immunoreactive cells as compared to non-invasive lesions. Almost all samples contained HPV, with a higher viral load and copy number of HPV16 integrated in E2 in cases of laminin-5 immunoreactivity and cases of invasive carcinoma. High HPV16 viral load was associated with more integrated copies in E2.

CONCLUSIONS

HPV is important in progression from carcinoma in situ to invasive carcinoma. Viral load and HPV integration influence the development of cervical cancer towards invasiveness. Overall HPV status may be more predictive of patient outcome and may influence patient management.

An immunohistochemical study of CD1a and CD83-positive infiltrating dendritic cell density in cervical neoplasia

Cervical carcinoma is the second leading cancer in women in Malaysia, after breast cancer. Human papillomavirus (HPV) has been implicated in the development of dysplasia or cervical intraepithelial neoplasia and progression to squamous cell carcinoma. Because of the confinement of the human papillomavirus infection within the epithelial layer, the presence of dentritic cells or Langerhans cells in epithelial layer of the ectocervix is paramount in producing immune response. The mature dentritic cells express CD83 and high CD40/80/86, whereas the immature cells express CD1a and low CD40/80/86. By identifying CD1a and CD83, theoretically, both immature and mature dentritic cell populations can be studied. In view of the facts, we investigated the infiltrating cell density of mature and immature dentritic cells in cervical neoplasia.

Langerhans Cells in Cervical Intraepithelial Neoplasia Related to Smoking Habits

OBJECTIVE

Compare the numerical densities of intraepithelial Langerhans cells of uterine cervix of women affected by cervical intraepithelial neoplasia grade 3 (CIN 3) with their smoking habits.

MATERIALS AND METHODS

A total of 71 conization specimens of women affected by CIN 3 were separated in 3 groups according to their smoking habits (smokers, nonsmokers, and former smokers). The identification of the Langerhans cells was performed by immunohistochemical analysis using antibodies to S100 protein. The number of intraepithelial Langerhans cells was counted at x400 magnification under a light microscope, and a 10-field count was performed in areas of CIN 3 of each section. Results were expressed as number of cells per square millimeter of epithelium.

RESULTS

There was no significant difference in the number of Langerhans cells per square millimeter of epithelium in areas affected by CIN 3 among the 3 groups (p = .5). There was also no significant difference in the number of cigarettes smoked per day (p = .09), duration of consumption (p = .34), total amount of cigarettes smoked during the whole life (p = .18), and duration of abstention (p = .2).

CONCLUSIONS

It was not shown that smoking reduces the number of intraepithelial Langerhans cells in the cervix of women affected by CIN 3.

Langerhans' cells and smoking in intraepithelial neoplasia of the cervix

OBJECTIVE

To compare the intraepithelial population of Langerhans' cells (LC) in normal cervix epithelium adjacent to cervical intraepithelial neoplasia grade 3 (CIN 3) and correlate to smoking habit.

METHODS

Cases in this study included conization specimens from 48 women affected by CIN 3. The LC count was performed in areas without histopathologic alteration adjacent to CIN 3. The control group is compound by normal cervix from 46 hysterectomy specimens. The identification of LC was done by immunohistochemical study demonstrating immunoreactivity to S-100 protein. The number of intraepithelial LC was determined using 400x magnification light microscope in 10 high-power fields, and results were expressed in number of cells per square millimeter (LC/mm(2)).

RESULTS

In the control group, there was lower number of Langerhans' cells in smokers than in non-smokers (P = 0.045). There was lower number of Langerhans' cells in normal areas adjacent to CIN 3 than in normal cervix control group (P = 0.004). There was no significant difference in the number of Langerhans' cells in normal areas of the cervix with CIN 3 between smokers and non-smokers (P = 0.991). The number of cigarettes consumed daily, time of consume, total number of cigarettes consumed showed a reduced LC count, yet was not statistically significant.

CONCLUSIONS

It was revealed that smoking reduces the number of intraepithelial Langerhans' cells in the uterine cervix. In women with CIN 3, the LC count was lower, despite the habit of smoking.

Oral administration of human papillomavirus type 16 E7 displayed onLactobacillus casei induces E7-specific antitumor effects in C57/BL6 mice

The mounting of a specific immune response against the human papillomavirus type 16 E7 protein (HPV16 E7) is important for eradication of HPV16 E7-expressing cancer cells from the cervical mucosa. To induce a mucosal immune response by oral delivery of the E7 antigen, we expressed the HPV16 E7 antigen on the surface of Lactobacillus casei by employing a novel display system in which the poly-gamma-glutamic acid (gamma-PGA) synthetase complex A (PgsA) from Bacillus subtilis (chungkookjang) was used as an anchoring motif. After surface expression of the HPV16 E7 protein was confirmed by Western blot, flow cytometry and immunofluorescence microscopy, mice were orally inoculated with L. casei-PgsA-E7. E7-specific serum IgG and mucosal IgA productions were enhanced after oral administration and significantly enhanced after boosting. Systemic and local cellular immunities were significantly increased after boosting, as shown by increased counts of lymphocytes (SI = 9.7 +/- 1.8) and IFN-gamma secreting cells [510 +/- 86 spot-forming cells/10(6)cells] among splenocytes and increased IFN-gamma in supernatants of vaginal lymphocytes. Furthermore, in an E7-based mouse tumor model, animals receiving orally administered L. casei-PgsA-E7 showed reduced tumor size and increased survival rate versus mice receiving control (L. casei-PgsA) immunization. These results collectively indicate that the oral administration of E7 displayed on lactobacillus induces cellular immunity and antitumor effects in mice.

Vaccination as a prevention strategy for human papillomavirus-related diseases

Childhood vaccines have had an enormously beneficial impact on human health. Large-scale vaccination programs have controlled diseases associated with high morbidity and mortality such as poliomyelitis, smallpox, diphtheria, tetanus, yellow fever, pertussis, Haemophilus influenzae, Streptococcus pneumoniae, measles, mumps, and rubella. Human papillomavirus (HPV) is a significant source of morbidity and mortality throughout the world. In the United States, HPV is the most common sexually transmitted infection (STI), and sexually active adolescents are at particularly high risk for HPV acquisition. Genetic and epidemiologic studies have clearly demonstrated that HPV infection is a necessary cause of both cervical cancer and genital warts. More than 99% of cervical cancers contain at least one high-risk HPV type, and approximately 70% contain HPV types 16 or 18. Moreover, low-risk HPV types 6 or 11 are responsible for approximately 90% of genital warts and almost all cases of recurrent respiratory papillomatosis. Thus, a vaccine that could prevent HPV acquisition would have the potential to significantly reduce the incidence of both childhood and adult diseases.

Human papillomavirus vaccines and adolescents

PURPOSE OF REVIEW

This review will describe human papillomavirus (HPV) vaccines in development, summarize data regarding safety and efficacy of these vaccines, and discuss key issues related to HPV vaccine implementation.

RECENT FINDINGS

Evidence from epidemiologic and genetic studies has confirmed that HPV infection is a necessary cause of cervical cancer and contributes to the development of other cancers. HPV infection also may cause nonmalignant conditions such as external genital warts and recurrent respiratory papillomatosis. Over the past decade, several vaccines that target common HPV types have entered clinical trials. These vaccines are classified as prophylactic or therapeutic. The goal of prophylactic vaccines is to prevent primary or persistent HPV infections, and thus prevent cervical cancer and/or genital warts. Recent evidence indicates that prophylactic vaccines are well tolerated, highly immunogenic and effective in preventing persistent HPV infection and cervical intraepithelial neoplasia (CIN). Questions remain, however, concerning vaccine efficacy against HPV-related diseases other than cervical cancer, the duration of protection, vaccine acceptability and feasibility of vaccine delivery in the developing world. The goal of therapeutic vaccines is to prevent progression of HPV infection, induce regression of CIN or condylomata, or eradicate residual cervical cancer. Although therapeutic vaccines appear to induce both humoral and cell-mediated immunity, they have not consistently demonstrated clinical efficacy.

SUMMARY

HPV vaccines in development have the potential to reduce the substantial morbidity and mortality associated with cervical cancer and other HPV-associated diseases. Large-scale efficacy studies that are planned or underway will provide additional information about vaccine tolerance and efficacy.

High-risk mucosal human papillomavirus infections during infancy & childhood

Human papillomaviruses (HPVs) are small DNA tumour viruses associated with a variety of proliferative diseases. More than 100 types have been identified and can broadly be grouped into cutaneous and mucosal types according to their site of infection, and can be further subdivided into low-risk (LR) and high-risk (HR) types depending upon their association with malignancy. The main route of transmission of HR mucosal HPVs is through sexual contact, although the acquisition of virus cannot be entirely explained by this mode alone. Evidence also exists for horizontal transmission by other routes and vertical transmission. HR HPVs, particularly HPV-16, have been detected in oral swabs from newborns, infants and children. Such alternative modes of transmission and acquisition may have an important impact in several areas, including vaccination strategies, epidemiological studies, and the clinical management of children with HPV-associated diseases. This article reviews the literature describing the detection of HPV infections during infancy and childhood and provides evidence for a role of vertical transmission in the spread of HPV infection.

Genital infection with human papillomavirus in adolescents

Human papillomavirus (HPV) infection is one of the most common sexually transmitted infections in adolescents. Such infection is associated with substantial health risks and is unpredictable in its resolution. Genital warts are the most common clinical manifestations of genital HPV infections. Most genital warts are caused by low risk HPV types (notably HPV-6 and -11). The majority of genital HPV infections are latent or subclinical. Although the outcome of a genital HPV infection is variable, the infection is usually transient and complete resolution is common. However, persistent infections with high-risk HPV types (notably HPV-16 and -18) are associated with the development of cervical intraepithelial dysplasia (CIN), which may progress to cervical cancer. Genital warts, generally diagnosed in the clinic, can be treated with imiquimod, podofilox, podophyllin, liquid nitrogen, bichloroacetic or trichloroacetic acid, or surgery. Cervical cytology screening is an ideal screening test for subclinical HPV infection with resultant CIN. Annual cervical cytology screening should begin approximately 3 years after initiation of sexual intercourse but no later than age 21 years. Because of the high rate of regression of low-grade squamous intraepithelial lesions (LSIL) in adolescents, the cytologic study should be repeated within 6 to 12 months. Colposcopy should be reserved for persistent LSIL. Patients with high-grade squamous intraepithelial lesions (HSIL) should be referred for colposcopy and biopsy. Confirmed HSIL should be treated with cryotherapy, laser therapy, or loop electrosurgical excisional procedure. The use of therapeutic vaccines is still experimental. HPV infection can be prevented, to a certain extent, by delaying the initiation of sexual activity, limiting the number of sexual partners, and using latex condoms. Several viruslike particle candidate vaccines are under development for the prevention of HPV. These vaccines have been proven safe, well tolerated, highly immunogenic, and highly efficacious. Such vaccines are urgently needed and ultimately may be an important preventive measure.

Enhanced mucosal and systemic immunogenicity of human papillomavirus-like particles encapsidating interleukin-2 gene adjuvant

Here, we report the enhanced mucosal and systemic immunogenicity of human papillomavirus type (HPV) 16 L1 virus-like particles (VLP) encapsidating a cytokine genetic adjuvant. Plasmid DNA expressing interleukin-2 (pIL2) was encapsidated in VLP using the reassembly property of VLP from disassembled L1 capsomeres. pIL2 in reassembled VLP showed stability against DNase I, indicating encapsidation. After intramuscular immunization into mice, the highest vaginal and salivary HPV16 L1-specific IgA titers were observed in pIL2-encapsidated VLP, followed by VLP plus pIL2 in separate plasmid, and VLP alone. Similar to mucosal responses, serum IgG, IgG1, and IgG2a antibody titers were the highest in the group treated with pIL2-encapsidated VLP. Moreover, the adjuvanticity of pIL2 encapsidated in VLP was stronger in IgG2a antibody relative to IgG1 antibody. Our results indicate that the encapsidation of a genetic cytokine adjuvant pIL2 would be beneficial for more effective induction of mucosal and systemic immune responses to VLP vaccines.

Human papillomavirus and cervical cancer: issues for biobehavioral and psychosocial research

There is now overwhelming evidence that high-risk, sexually transmitted types of human papillomavirus (HPV) are the main causal agent in cervical cancer. Biobehavioral and psychosocial research is uniquely capable of addressing many of the issues raised by HPV and its link with cervical cancer. In this article we review current findings in this area and identify issues for future research. The first of the three sections explores issues associated with the introduction of HPV testing for the detection and management of cervical abnormalities and the impact of growing public awareness of the sexually transmitted nature of cervical cancer. The implications for public understanding of cervical cancer, psychosocial issues associated with screening, and the potential impact on screening uptake are discussed. The second section addresses the role of biobehavioral factors in the persistence and progression of HPV infection as well as possible interventions to minimize the risk of persistence. Finally, primary prevention of HPV is discussed.

Characterization of HPV16 L1 loop domains in the formation of a type-specific, conformational epitope

Background

Virus-like particles (VLPs) formed by the human papillomavirus (HPV) L1 capsid protein are currently being tested in clinical trials as prophylactic vaccines against genital warts and cervical cancer. The efficacy of these vaccines is critically dependent upon L1 type-specific conformational epitopes. To investigate the molecular determinants of the HPV16 L1 conformational epitope recognized by monoclonal antibody 16A, we utilized a domain-swapping approach to generate a series of L1 proteins composed of a canine oral papillomavirus (COPV) L1 backbone containing different regions of HPV16 L1.

Results

Gross domain swaps, which did not alter the ability of L1 to assemble into VLPs, demonstrated that the L1 N-terminus encodes at least a component of the 16A antigenic determinant. Finer epitope mapping, using GST-L1 fusion proteins, mapped the 16A epitope to the L1 variable regions I and possibly II within the N-terminus.

Conclusions

These results suggest that non-contiguous loop regions of L1 display critical components of a type-specific, conformational epitope.

Enhanced mucosal and systemic immune responses following intravaginal immunization with human papillomavirus 16 L1 virus-like particle vaccine in thermosensitive mucoadhesive delivery systems

To develop more potent and convenient mucosal human papillomavirus (HPV) vaccines, we tested the effect of thermosensitive mucoadhesive vaginal vaccine delivery systems on the local and systemic antibody responses to HPV 16 L1 virus-like particles (VLP). HPV 16 L1 VLP expressed from recombinant baculovirus-infected Sf21 insect cells were delivered in phosphate-buffered saline (PBS) or thermosensitive mucoadhesive delivery systems, composed of poloxamers (Pol) and varying amounts of polyethylene oxide (PEO). Pol/PEO-based vaginal vaccine delivery systems existed in liquid form at room temperature, but gelled at 37 degrees C. The mucoadhesiveness of Pol/PEO-based delivery systems increased with PEO, but the formulations with PEO higher than 1.0% were too viscous to be administered into the vagina. Vaccine vehicles affected the vaginal and salivary immune responses to HPV 16 L1 VLP intravaginally administered into mice. At 42 days after the first intravaginal immunization of HPV 16 L1 VLP with cholera toxin, vaginal and salivary IgA titers were the highest in the group given in Pol/PEO 1.0% vehicle followed by Pol/PEO 0.4% and PBS vehicles. Intravaginal coadministration of HPV 16 L1 VLP and cholera toxin in Pol/PEO 1.0% showed 31- and 39-fold higher titers compared to the PBS-based HPV 16 L1 VLP groups administered by intravaginal and intramuscular routes, respectively. Following intravaginal administration, Pol/PEO 1.0%, but not Pol/PEO 0.4%, showed significantly higher HPV 16 L1 VLP-specific serum IgG titers as compared to the PBS vehicle. Our results indicate that the use of in situ-gelling vaginal vaccine delivery systems with increased mucoadhesiveness would be beneficial for more effective induction of mucosal and systemic immune responses to intravaginally administered HPV 16 L1 VLP vaccines.

Enhanced immunogenicity of human papillomavirus 16 L1 genetic vaccines fused to an ER-targeting secretory signal peptide and RANTES

To increase the potency of human papillomavirus (HPV) DNA vaccines, we constructed a series of HPV16 L1 vaccines genetically fused with a secretion signal and/or immune cell-recruiting RANTES. The DNA vaccines encoding secretory HPV L1 were constructed by inserting HPV L1 gene into a vector with an ER-targeting secretory signal sequence. The expression plasmid encoding secretory HPV L1 (pER/L1) was fused with cDNA of RANTES, generating pER/L1/R. For comparison, HPV L1 genes were cloned into pVAX1 vector with no signal sequence (pL1), and further linked to the N-terminus (pL1/R) or C-terminus of RANTES (pR/L1). The secretion of L1 proteins was observed in the pER/L1, pER/L1/R, and pR/L1-transfected cells, except the pL1/R-transfected group. Cytoplasmic localization of L1 protein was observed in the cells transfected with pL1/R, but not with pER/L1/R at 48 h after transfection. In mice, RANTES-fused vaccines more effectively elicited the levels of HPV16 L1-specific IgG and IgG2a antibodies than pL1. Of RANTES-fused vaccines, pER/L1/R encoding the secreted fusion protein induced the highest humoral and CD8(+) T-cell-stimulating responses. These results suggest that the immunogenicity of HPV L1 DNA vaccines could be enhanced by genetic fusion to a chemokine and secretory signal peptide sequences.

Interplay between human papillomaviruses and dendritic cells

The design of the human papillomavirus (HPV) infection cycle is tightly fitted to the differentiation program of its natural host, the keratinocyte. This has important consequences for the role of antigen-presenting cells in the priming of antiviral immunity. The confinement of HPV infection to epithelia puts the epithelial dendritic cell, the Langerhans cell (LC), in charge of the induction of T cell-dependent immunity. Because HPV-infected keratinocytes cannot reach the regional lymphoid organs, and HPV-infection of LCs does not result in viral gene expression, priming of antiviral T cells exclusively depends on cross-presentation of viral antigens by the LC. Sensitization of the immune system in the regional lymphoid organs elicits systemic anti-HPV immunity as well as intraepithelial immune surveillance by memory-type intraepithelial T cells and locally produced antibodies. The high rate of spontaneous rejections of high-risk HPV-infections and HPV-positive premalignant lesions indicates that in general the LC-driven antigen presentation machinery is capable of raising an effective immune defense against HPV. Epidemiological studies also reveal that a decrease in the vigilance of the immune system is readily exploited by HPV to escape immune destruction, resulting in persistent infections and development of HPV-positive cancers. In view of the inherent antigenicity of HPV, immune intervention strategies constitute a promising approach for both the prevention and the therapeutic treatment of HPV-induced diseases. Importantly, the mechanisms that govern the induction and effector phases of the intraepithelial immune surveillance against HPV must be taken into account when designing such strategies.

Cervicovaginal coinfections with human papillomavirus and Chlamydia trachomatis

Human papillomavirus (HPV) and Chlamydia trachomatis (CT) are the two most common sexually transmitted pathogens, and infection with either reportedly was associated with cervical intraepithelial neoplasia (CIN) in women. In view of their similar mode of transmission, CT infection was examined as a possible HPV cofactor in the etiology of CIN disease. In total, 129 women were included in the study, of whom 80 were negative (mean age 34.17 +/- 6.9) and 49 were positive (mean age 33.16 +/- 6.8) for HPV DNA (assessed by PCR). CT DNA was determined in endocervical and first-catch urine specimens by PCR. Whereas HPV-positive and HPV-negative women were similar with respect to age (p = 0.419) and pregnancy outcomes (p = 0.628), the number of smokers (p = 0.001), women with multiple male sex partners (p = 0.002) or with abnormal cytology (p < 0.001) was higher in the HPV-positive group. There was an increase in CT infection rate in HPV-positive (29/49) as compared to HPV-negative (10/80) women (p < 0.01). Within HPV-positive patients, there was no significant difference between CT-positive and CT-negative patients with regards to the risk factors studied. Collectively, this suggests that CT infection is a cofactor of HPV in CIN disease development, possibly by modulating the host's immunity and/or precipitation of chronic inflammation.

Preinvasive diseases of the cervix, vulva, and vagina

OBJECTIVES

To discuss the epidemiology, treatment, and psychosocial implications of preinvasive disease of the lower genital tract.

DATA SOURCES

Review articles, research studies, and government publications.

CONCLUSIONS

Routine cervical cytology has been one of the most successful public health screening programs accomplished over the last 50 years. However, our success has plateaued. The focus now is to address existing barriers to screening and treatment, and to develop an effective triage protocol for the management of abnormal cervical cytology. IMPLICATIONS FOR NURSING CARE: Nurses as patient advocates are best prepared to meet the culturally sensitive, financially, and geographical challenges of addressing barriers to screening and treatment.

Interactions of the female hormonal environment, susceptibility to viral infections, and disease progression

Sex hormones influence susceptibility and disease predisposition for many genital tract infections. This review describes the mechanisms by which sex steroids affect mucosal immunity, with particular reference to human immunodeficiency virus (HIV) and genital herpes, and the stage-specific effects of hormonal contraception on human papillomavirus (HPV) infection. Estrogen's role is important in the early stages of several infections as it stimulates antibody- and cell-mediated immune responses. There is increased expression of some cytokines in peripheral blood and vaginal fluids during the follicular phase of the menstrual cycle and with use of hormonal contraception. Whether estrogen exerts a protective or deleterious influence depends on the infecting organism and stage of infection or disease. Estrogen apparently reduces susceptibility to primary HPV infection but in the event of persistent HPV infection, sex steroid hormones (estrogen and/or progesterone) are associated with progression to cervical cancer. It is important that these stage-specific effects are better described because most vaccines will try to prevent either infection or disease. Clinicians with patients at high risk of sexually transmitted infections, especially HIV, require better information on the risks associated with different hormonal contraceptive regimes.

Alterations in promoter usage and expression levels of insulin-like growth factor-II and H19 genes in cervical carcinoma exhibiting biallelic expression of IGF-II

Biallelic expression of insulin-like growth factor-II (IGF2) has been reported to be associated with progression of several tumors. Here, we report that the promoter usage and expression levels of IGF2 and H19 were altered in cervical carcinoma showing loss of imprinting. The imprinting status was examined in 32 cervical carcinomas and their matched normal tissues. Loss of imprinting (LOI) of IGF2 was observed in seven of 18 (39%) informative cases. LOI of H19 gene was detected in five of 14 informative cases. The usage of promoter P1 was observed in LOI tumors of IGF2, but not in the tumors showing maintenance of IGF2 imprinting (MOI) and in the normal cervical tissues. Unlike MOI tumors, some LOI tumors revealed the lack of IGF2 transcription from promoter P3. LOI tumors of IGF2 showed an increased expression level of IGF2 but a down-regulation of H19 relative to the normal tissues whereas MOI tumors did not reveal significant alterations. These results suggest that promoter P1 could be involved in the biallelic expression of IGF2 and that the altered expression levels of IGF2 and H19 gene might be associated with the progression of cervical carcinoma showing biallelic expression of IGF2.

Genital human papillomavirus infections

Human papillomavirus infections of the genitals are very widespread in the sexually active population throughout the world. Not only cosmetically unattractive skin warts but also genital squamous epithelial carcinomas of both sexes may be caused by human papillomavirus infections. In the past 30 years, this has led to intensive research on human papillomavirus. This paper reviews and evaluates the current literature on the pathomechanism, diagnostics, therapy, risk groups and clinical significance of human papillomavirus in urology and other specialties.