Human papillomaviruses and genital cancer

The vaginal metabolome and microbiota of cervical HPV-positive and HPV-negative women: a cross-sectional analysis

OBJECTIVE

Characterise the vaginal metabolome of cervical HPV-infected and uninfected women.

DESIGN

Cross-sectional.

SETTING

The Center for Health Behavior Research at the University of Maryland School of Public Health.

SAMPLE

Thirty-nine participants, 13 categorised as HPV-negative and 26 as HPV-positive (any genotype; HPV⁺ ), 14 of whom were positive with at least one high-risk HPV strain (hrHPV).

METHOD

Self-collected mid-vaginal swabs were profiled for bacterial composition by 16S rRNA gene amplicon sequencing, metabolites by both gas and liquid chromatography mass spectrometry, and 37 types of HPV DNA.

MAIN OUTCOME MEASURES

Metabolite abundances.

RESULTS

Vaginal microbiota clustered into Community State Type (CST) I (Lactobacillus crispatus-dominated), CST III (Lactobacillus iners-dominated), and CST IV (low-Lactobacillus, 'molecular-BV'). HPV⁺ women had higher biogenic amine and phospholipid concentrations compared with HPV^- women after adjustment for CST and cigarette smoking. Metabolomic profiles of HPV⁺ and HPV^- women differed in strata of CST. In CST III, there were higher concentrations of biogenic amines and glycogen-related metabolites in HPV⁺ women than in HPV^- women. In CST IV, there were lower concentrations of glutathione, glycogen, and phospholipid-related metabolites in HPV⁺ participants than in HPV^- participants. Across all CSTs, women with hrHPV strains had lower concentrations of amino acids, lipids, and peptides compared with women who had only low-risk HPV (lrHPV).

CONCLUSIONS

The vaginal metabolome of HPV⁺ women differed from HPV^- women in terms of several metabolites, including biogenic amines, glutathione, and lipid-related metabolites. If the temporal relation between increased levels of reduced glutathione and oxidised glutathione and HPV incidence/persistence is confirmed in future studies, anti-oxidant therapies may be considered as a non-surgical HPV control intervention.

TWEETABLE ABSTRACT

Metabolomics study: Vaginal microenvironment of HPV⁺ women may be informative for non-surgical interventions.

eIF4E is a critical regulator of human papillomavirus (HPV)-immortalized cervical epithelial (H8) cell growth induced by nicotine

Tobacco smoke is known as a cofactor in the development of cervical precancer and cancer caused by human papillomavirus (HPV). The main component in cigarette smoke, nicotine, can be concentrated more strongly in cervical mucus than in blood and it has been implicated as a cocarcinogen that promotes a serial of cancers development through multiple prosurvival pathways. Although the mechanisms of nicotine-induced cell proliferation have been well studied in some epithelial cells, the molecular mechanism of its action in cervical epithelial cells is still unclear. The aims of this study were to investigate the detailed mechanism by which nicotine could induce cervical cancer growth. We found that nicotine simultaneously activates AKT/mTOR pathway in HPV-immortalized cervical epithelial (H8) cell line, followed by elevation of 4EBP1/eIF4E axis expression and its translational activity with dose-dependent and time-dependent manners. Besides, nicotine decreases eIF4E-4EBP1 binding activity in H8 cell line, which is associated with increased expression of phospho-4EBP1 at threonine 70. We therefore chose to evaluate whether this effect on eIF4E was involved in nicotine-induced proliferation. Remarkably, eIF4E knockdown by small interfering RNA diminishes its translation activity to the downstream targets including c-Myc, VEGF, CyclinD1 and Bcl-2. What is more, eIF4E knockdown inhibits cellular growth and colony formation after nicotine treatment. Note as well that eIF4E-specific siRNA could also suppress cell proliferation by decelerating the G0/G1-S transition of H8 cell treated with nicotine. Taken together, it can be concluded that nicotine promotes H8 cell proliferation by activating AKT/mTOR pathway, as well as 4EBP1/eIF4E axis and its translational activity. Furthermore, phosphorylation of 4EBP1 induced by nicotine has been shown to cause dissociation of 4EBP1/eIF4E and eIF4E may serve as a promising determinant of nicotine activity in vitro.

Linear epitope prediction in HPV type 16 E7 antigen and their docked interaction with human TMEM 50A structural model

Human Papilloma Virus (HPV) HPV type 16 E7 antigen is a known target in cervical cancer. We report the predicted potential epitopes in the E7 antigen. We further describe the subsequent interaction of these linear epitope peptides with the human TMEM 50 A structural model using molecular docking. This data finds application in the development of components towards HPV associated disease prevention.

Susceptibility of HPV16 and 18 to high level disinfectants indicated for semi-critical ultrasound probes

Ultrasound probes used in endocavitary procedures have been shown to be contaminated with high‐risk HPV after routine use and HPV is also known to be resistant to some high level disinfectants (HLDs). This study compared efficacy of two leading ultrasound probe HLD methods; liquid ortho‐phthalaldehyde (Cidex® OPA) and an automated device using sonicated hydrogen peroxide (trophon® EPR) against HPV16 and HPV18 in a hard‐surface carrier test. Native HPV16 and HPV18 virions were generated in organotypic epithelial raft cultures. Viral lysates were dried onto carriers with a 5% (v/v) protein soil. Efficacy tests were performed against the automated device at 35% and 31.5% H₂O₂ and 0.55% OPA in quadruplicate with matched input, neutralization, and cytotoxicity controls. Hypochlorite was included as a positive control. Infectivity was determined by the abundance (qRT‐PCR) of the spliced E1^E4 transcript in infected recipient cells. The automated HLD device showed excellent efficacy against HPV16 and HPV18 (>5 log₁₀ reductions in infectivity) whereas OPA showed minimal efficacy (<0.6 log₁₀ reductions). While HPV is highly resistant to OPA, sonicated hydrogen peroxide offers an effective disinfection solution for ultrasound probes. Disinfection methods that are effective against HPV should be adopted where possible. J. Med. Virol. 88:1076–1080, 2016. © 2015 The Authors. Journal of Medical Virology Published by Wiley Periodicals, Inc.

Genotype distribution of human papillomavirus (HPV) in histological sections of cervical intraepithelial neoplasia and invasive cervical carcinoma in Madrid, Spain

Background

Human Papillomavirus (HPV) genotype distribution and co-infection occurrence was studied in cervical specimens from the city of Madrid (Spain), as a contribution to the knowledge of Human Papillomavirus genotype distribution and prevalence of carcinogenic HPV types in cervical lesions in Spain.

Methods

A total of 533 abnormal specimens, from the Hospital General Universitario “Gregorio Marañón” of Madrid, were studied. These included 19 benign lesions, 349 cervical intraepithelial neoplasias 1 (CIN1), 158 CIN2-3 and 7 invasive cervical carcinomas (ICC). HPV genotyping was performed using PCR and tube array hybridization.

Results

We detected 20 different HPV types: 13 carcinogenic high-risk HPV types (HR-HPVs), 2 probably carcinogenic high-risk HPV types (PHR-HPVs) and 5 carcinogenic low-risk HPV types (LR-HPVs). The most frequent HPV genotypes found in all specimens were HPV16 (26.0%), 31 (10.7%) and 58 (8.0%). HPV 18 was only detected in 5.0%. Co-infections were found in 30.7% of CIN 1 and 18.4% cases of CIN2-3. The highest percentage of HR HPVs was found in those specimens with a CIN2-3 lesion (93.7%).

Conclusion

As our study shows the current tetravalent vaccine could be effective in our geographical area for preventing all the invasive cervical carcinomas. In addition, upon the estimates of the important presence of other HR-HPV types – such as 31, 58, 33 and 52 – in different preneoplasic lesions the effectiveness of HPV vaccination in our geographical area, and others with similar genotype distribution, should be limited.

Human papillomavirus infection and its association with cervical dysplasia in Ecuadorian women attending a private cancer screening clinic

Women living in Latin American countries bear a disproportionate burden of cervical cancer, a condition caused by infection with the human papillomavirus (HPV). We performed a study in Santa Elena, Guayas (currently Santa Elena Province), Ecuador, to determine how often HPV could be detected in women attending a private cancer screening clinic. Participants underwent a Pap test, and vaginal and cervical swabs were performed for HPV testing by the polymerase chain reaction (PCR). Each participant completed a verbally administered survey. The mean age of 302 participants was 37.7 years (range 18 to 78 years). The majority of cervical and vaginal specimens contained sufficient DNA to perform PCR. Overall, 24.2% of the participants had either a cervical or vaginal swab that tested positive for HPV. In general, there was a good correlation between the HPV types detected in the cervical and vaginal swabs from the participants, but vaginal swabs were more likely to contain HPV DNA than were cervical swabs. The high-risk HPV types 16, 52, 58, and 59 and the low-risk HPV types 62, 71, 72, and 83 were the most frequently detected HPV types. The number of lifetime sexual partners was positively associated with detection of any HPV type, detection of oncogenic HPV, and abnormal Pap smears. Further studies are needed to determine if these results are representative of all Ecuadorian women and to determine if cervical cancers in Ecuadorian women are caused by the same HPV types found in the swab specimens obtained in this study.

Expression of the p16 and Ki-67 in relation to the grade of cervical intraepithelial neoplasia and high-risk human papillomavirus infection

OBJECTIVE

The purposes of this study were to evaluate the expression of p16(INK4a) (referred as to p16) and Ki-67 in cervical intraepithelial neoplasia (CIN), and the correlation between high-risk human papillomavirus (HPV) infection and the above biomarkers.

METHODS

We analyzed 31 patients who were diagnosed with CIN at Kwandong University Myongji Hospital from October 2006 to September 2007. CIN specimens (CIN1, 12; CIN2, 6; CIN3, 13) were obtained by colposcopy-directed biopsy (CDB) or loop electrical excision procedure (LEEP). The expressions of p16 and Ki-67 were evaluated by immunohistochemical methods with antibodies to p16 and Ki67. The immunohistochemical staining results were classified into four grades: 0, 1, 2 and 3. HPV genotyping or Hybrid Capture-II test was used to detect high-risk HPV.

RESULTS

The expression of p16 (p<0.001) and Ki-67 (p=0.003) were positively associated with CIN grade. p16 expressions increased significantly with high-risk HPV infection (p=0.014), especially HPV type 16 and 58. Ki-67 expression was not related with high-risk HPV. There was positive correlation between the expression of the p16 and Ki-67 (p=0.007).

CONCLUSION

CIN grade were positively related to the expression of p16 and Ki-67. p16 expressions of high-risk HPV specimens significantly increased more than Ki-67. Therefore, in the diagnosis of CIN and high-risk HPV infection, p16 can be a useful biomarker.

Incidence, mortality, and prognostic factors of small cell carcinoma of the cervix

OBJECTIVE

To compare the incidence, mortality, and presentation of small cell carcinoma of the cervix with other histologies.

METHODS

From 1977 to 2003, 290 women with small cell carcinoma of the cervix uteri were identified from the Surveillance, Epidemiology, and End Results database. Also, 27,527 patients with squamous cell carcinoma of the cervix and 5,231 patients with adenocarcinoma of the cervix were identified for comparison. The annual incidence was calculated and examined for trend. Patient and disease characteristics were compared among histologies. Univariable analyses were conducted using the log-rank test. Multivariable analysis was performed using Cox regression.

RESULTS

The mean annual incidence for small cell carcinoma was 0.06 per 100,000 women, compared with 6.6 and 1.2 for squamous cell carcinoma and adenocarcinoma, respectively. There were significant differences at presentation between small cell carcinoma compared with squamous cell carcinoma and adenocarcinoma for race, treatment, International Federation of Gynecology and Obstetrics stage, and lymph node involvement (P<.05). A trend for improved survival was identified for adenocarcinoma (P=.036) and squamous cell carcinoma (P<.001) but not for small cell carcinoma (P=.672). Five-year survival for small cell carcinoma (35.7%) was worse compared with squamous cell carcinoma (60.5%, hazard ratio 0.55; 95% confidence interval (CI) 0.43-0.69) and adenocarcinoma (69.7%, hazard ratio 0.48; 95% CI 0.37-0.61). On multivariable analysis, age, stage, and race were prognostic for survival in women with small cell carcinoma (P<.05).

CONCLUSION

Small cell carcinoma is a rare histology of cervical cancer associated with a worse prognosis and a predilection for nodal and distant metastasis. The decrease in survival was marked in early-stage and node-negative patients. Because of the high rates of nodal involvement even with early-stage disease, multimodality treatment with radiotherapy and chemotherapy should be considered.

LEVEL OF EVIDENCE

II.

The cigarette smoke carcinogen benzo[a]pyrene enhances human papillomavirus synthesis

Epidemiological studies suggest that cigarette smoke carcinogens are cofactors which synergize with human papillomavirus (HPV) to increase the risk of cervical cancer progression. Benzo[a]pyrene (BaP), a major carcinogen in cigarette smoke, is detected in the cervical mucus and may interact with HPV. Exposure of cervical cells to high concentrations of BaP resulted in a 10-fold increase in HPV type 31 (HPV31) viral titers, whereas treatment with low concentrations of BaP resulted in an increased number of HPV genome copies but not an increase in virion morphogenesis. BaP exposure also increased HPV16 and HPV18 viral titers. Overall, BaP modulation of the HPV life cycle could potentially enhance viral persistence, host tissue carcinogenesis, and permissiveness for cancer progression.

The expressions of the Rb pathway in cervical intraepithelial neoplasia; predictive and prognostic significance

OBJECTIVES

The aim of the study was to assess the expression of the Rb pathway (p16(INK4a)-cdk4-pRb) in cervical intraepithelial neoplasia as a prognostic marker by investigating the association between expression of Rb pathway and the recurrence.

METHODS

The study group comprised of 265 paraffin-embedded tissues of the uterine cervix collected from patients between 2001 and 2003. Patients underwent ablative or excisional treatment and were followed for 2 years. RB pathway expression was examined using immunohistochemistry applied to a tissue microarray. HPV detection and genotyping were performed with HPV DNA Chip. Statistical analysis was done by ANOVA test, Student's t test, and Pearson's correlation test.

RESULTS

With increasing CIN grade, p16(INK4a) and cdk4 expression rates increased, while the pRb expression rate decreased. The expression rate of p16(INK4a) was higher (33%) in CIN I with high-risk HPV infection than in CIN I without high-risk HPV infection (19%). The mean expression rates of p16(INK4a) were 29%, 39%, and 64%, respectively, in CIN I, II, and III without recurrence, but 25%, 28%, and 44% in those with recurrence. The mean expression rates of pRb were 47%, 40%, and 18% in CIN I, II, and III without recurrence, respectively, but 48%, 45%, and 34% in those with recurrence.

CONCLUSION

A relatively low expression rate of p16(INK4a) has prognostic significance for predicting recurrence. The clinical utility of p16(INK4a) status for stratifying patients according to their need for aggressive treatment requires further investigation.

Replication and interaction of herpes simplex virus and human papillomavirus in differentiating host epithelial tissue

We have investigated the interactions and consequences of superinfecting and coreplication of human papillomavirus (HPV) and herpes simplex virus (HSV) in human epithelial organotypic (raft) culture tissues. In HPV-positive tissues, HSV infection and replication induced significant cytopathic effects (CPE), but the tissues were able to recover and maintain a certain degree of tissue integrity and architecture. HPV31b not only maintained the episomal state of its genomic DNA but also maintained its genomic copy number even during times of extensive HSV-induced CPE. E2 transcripts encoded by HPV31b were undetectable even though HPV31b replication was maintained in HSV- infected raft tissues. Expression of HPV31b oncogenes (E6 and E7) was also repressed but to a lesser degree than was E2 expression. The extent of CPE induced by HSV is dependent on the magnitude of HPV replication and gene expression at the time of HSV infection. During active HSV infection, HPV maintains its genomic copy number even though genes required for its replication were repressed. These studies provide new insight into the complex interaction between two common human sexually transmitted viruses in an in vitro system, modeling their natural host tissue in vivo.

Changes in retinoblastoma gene expression during cervical cancer progression

The role of tumour suppressor genes in the development of human cancers has been studied extensively. In viral carcinogenesis, the inactivation of suppressor proteins such as retinoblastoma (pRb) and p53, and cellular oncogenes overexpression, such as c-myc, has been the subject of a number of investigations. In uterine-cervix carcinomas, where high-risk human papillomavirus (HPV) plays an important role, pRb and p53 are inactivated by E7 and E6 viral oncoproteins, respectively. However, little is known about the in situ expression of some of these proteins in pre-malignant and malignant cervical tissues. On the other hand, it has also been demonstrated that c-myc is involved in cervical carcinogenesis, and that pRb participates in the control of c-myc gene expression. By using immunostaining techniques, we investigated pRb immunodetection pattern in normal tissues, squamous intraepithelial lesions (SILs) and invasive carcinomas from the uterine cervix. Our data show low pRb detection in both normal cervical tissue and invasive lesions, but a higher expression in SILs. C-Myc protein was observed in most of the cellular nuclei of the invasive lesions, while in SILs was low. These findings indicate a heterogeneous pRb immunostaining during the different stages of cervical carcinogenesis, and suggest that this staining pattern could be a common feature implicated in the pathogenesis of uterine-cervix carcinoma.

Abrogation of IRF-1 response by high-risk HPV E7 protein in vivo

We have previously reported that human papillomavirus (HPV) E7 interacts with IRF-1, a key regulator of cellular immune response, and abrogates its transactivation function at the molecular level in vitro. To confirm our previous data, we investigated in vivo the E7-mediated down-regulation of IRF-1 using HPV E7-inducible cells and transgenic mice expressing HPV-18 E6/E7. When E7 was induced in the absence of tetracycline, the expression of target genes of IRF-1 (TAP-1, IFN-beta, MCP-1 that are important for cellular immunity) was clearly reduced as determined by RT-PCR. In addition, the IRF-1 activity was down-regulated in E7-expressing cells into which IFN-beta-CAT reporter plasmid was transfected. To further investigate the E7-mediated immune regulation in vivo, we constructed transgenic mice expressing E6 and E7 genes of HPV-18 under the control of HPV-18 promoter (URR). From several rounds of breeding, we obtained from a transgenic line that developed a cervical dysplasia and expressed E6/E7 as determined by histological examination and RT-PCR, respectively. Subsequent RT-PCR analysis indicated that TAP-1, IFN-beta, and MCP-1 genes were less expressed in a cervical tissue derived from transgenic mouse, when compared with a cervix derived from normal mouse. From these results, we conclude that the E7 transgene expression inactivates the transactivation function of IRF-1 in vivo, which might be important for the elucidation of the E7-mediated immune evading mechanism that is frequently found in cervical cancer.

Human papillomavirus 16 and 18 expression in conjunctival intraepithelial neoplasia

OBJECTIVE

To evaluate conjunctival intraepithelial neoplasia (CIN) and normal conjunctiva for the presence of human papillomavirus (HPV) DNA and for expression (as detected by the presence of mRNA) of the HPV E6 region.

DESIGN

Prospective, case-controlled study.

PARTICIPANTS

Ten consecutive patients who underwent CIN excision by one surgeon (CLK) and five age-matched control subjects who underwent retinal detachment repair at the Bascom Palmer Eye Institute.

METHODS

A reverse transcriptase in situ polymerase chain reaction (PCR) technique was used to search for the presence of HPV mRNA in CIN specimens from 10 consecutive patients who underwent CIN excision by one surgeon (CLK) at Bascom Palmer Eye Institute, as well as in clinically uninvolved conjunctival specimens from the same eyes of these patients. In addition, conjunctival specimens from five control subjects (age-matched to five of the cases), who had no clinically identifiable conjunctival disease and who underwent retinal detachment repair at the Bascom Palmer Eye Institute, were analyzed in a similar manner. The clinical diagnoses of CIN and normal conjunctiva were confirmed histopathologically in all cases by an ocular pathologist, who was masked as to the patients' clinical diagnoses, and the PCR testing was performed by an investigator (GJN) who was masked as to the clinical diagnoses.

RESULTS

HPV 16 DNA and mRNA were present in five CIN specimens, and HPV 18 DNA and mRNA were present in the other five CIN specimens; neither HPV 16 or 18 DNA nor mRNA were detected in any of the control specimens or in any of the clinically uninvolved conjunctival specimens (P < 0.001). In each of the CIN specimens, 20% to 40% of the dysplastic cells expressed the HPV E6 region.

CONCLUSIONS

HPV 16 or 18 DNA and mRNA corresponding to the E6 region were detected in all CIN specimens examined. HPV 16 or 18 DNA or mRNA was not present in any of the control or uninvolved conjunctival specimens. The consistency of the current findings with those reported for human cervical malignant lesions, and the fact that the protein encoded by the E6 region of HPV 16 and 18 has been shown to form a complex with the protein encoded by the host tumor suppressor gene p53, provide strong evidence for an etiologic role of HPV in the development of CIN.

Expression of cytokeratin 16 in human papillomavirus type 11-infected genital epithelium

During normal keratinocyte differentiation, a coordinated expression of many cytoskeletal and regulatory proteins occurs. Several studies suggest that expression of some of these proteins is altered in epithelium infected by the human papillomavirus (HPV). To examine protein expression, human foreskin tissue was infected with either the low-risk HPV type 11 or with HPV 83, a high-risk type. The foreskin tissue was implanted and grown in the athymic mouse xenograft system. Immunohistochemistry and immunoblot analysis of human foreskin xenografts were performed to detect cytokeratin 16 (K16), a protein previously identified in proliferative disorders of the skin. K16 was abundant in HPV 11-infected xenograft tissue, but was not detected in uninfected or HPV 83-infected tissue. Analysis of protein extracted from human biopsy tissue demonstrated the same expression patterns in natural infection by HPV 11. Reverse transcriptase PCR detected mRNA transcripts for K16 in both experimental and natural HPV 11-infected tissues, but not in uninfected tissue. These studies suggest that K16 overexpression during HPV 11-infection is regulated at the level of transcription. The marked epithelial proliferation that occurs in HPV 11 infection may involve alterations in expression of cytoskeletal proteins, including K16. Determining the mechanisms of K16 transcriptional induction could lead to therapies with the ability to reduce cell proliferation within infected tissue.

Validity of vaginal testing in detecting human papillomavirus (HPV) genotypes

The aim of this study was to assess the validity and usefulness of vaginal scrapes in detecting cervical human papillomavirus (HPV) DNA by the polymerase chain reaction (PCR). The study group comprised 23 women tested positive and 28 women tested negative for cervical HPV DNA by PCR, and confirmed by histopathology. At the time of specimen collection, both vaginal and endocervical scrapes were taken from these women, and tested for HPV DNA by PCR, using MY09/MY11 primer system. HPV genotypes were analyzed by hybridizing PCR products with HPV type-specific biotinylated probes. HPV DNA was detected in both vaginal and cervical scrapes from the HPV-positive, but not from HPV-negative group. In the HPV-positive group, the same HPV type was found in vaginal and endocervical scrapes, giving a positive predictive value of 1.0. The results indicate that HPV types can be detected in vaginal scrapes, and recommend utilization of the less invasive vaginal testing for the routine detection of HPV DNA.

The human papillomavirus type 11 E1E4 protein is phosphorylated in genital epithelium

The most abundant viral transcript in human papillomavirus (HPV) 11-infected xenograft tissue has been shown to encode the E1(wedge)E4 protein. The function of E1(wedge)E4 protein has not been determined. Several potential phosphorylation sequence motifs were identified in the HPV 11 E1(wedge)E4 protein, including potential sites of phosphorylation by mitogen-activated protein kinase (MAPK), cAMP-dependent protein kinase (PKA), casein kinase II, and protein kinase C. To test phosphorylation of the HPV 11 E1(wedge)E4 protein, a soluble maltose binding protein (MBP) fusion was produced in Escherichia coli. Only MAPK and PKA phosphorylated the E1(wedge)E4 protein. Phosphoamino acid analysis showed that one or more threonine residues were phosphorylated by MAPK, and both serine and threonine residues were phosphorylated by PKA. MBP-E1(wedge)E4 mutant proteins were designed to delineate the E1(wedge)E4 phosphoacceptor residues. MAPK was shown to phosphorylate E1(wedge)E4 on threonine 53 within a MAPK consensus phorphorylation sequence motif. PKA was shown to phosphorylate E1(wedge)E4 at two residues: threonine 36 within a consensus motif and serine 44 within a variant of the PKA consensus phosphorylation sequence motif. HPV 11-infected human genital tissue grown as a xenograft in an athymic mouse was labeled with [(32)P]orthophosphate. Phosphoamino acid analysis of E1(wedge)E4 protein immunoprecipitated from (32)P-labeled tissue revealed that both serine and threonine residues were phosphorylated. Analysis by liquid chromatography-mass spectrophotometry was consistent with phosphorylation of residues within the PKA and MAPK phosphorylation sequence motifs. Expression of E1(wedge)E4 protein containing phosphorylation substitution mutations showed that the PKA mutant did not differ from wild-type E1(wedge)E4 protein in intracellular distribution. In contrast, the MAPK mutant did not localize exclusively to the cytoplasm nor did it colocalize with wild-type E1(wedge)E4 protein. We conclude that HPV 11 E1(wedge)E4 protein is phosphorylated in vitro and in vivo. Our data are consistent with phosphorylation of HPV 11 E1(wedge)E4 protein by MAPK and PKA in infected tissue.

Inactivation of interferon regulatory factor-1 tumor suppressor protein by HPV E7 oncoprotein. Implication for the E7-mediated immune evasion mechanism in cervical carcinogenesis

In studying biological roles of interferon regulatory factor (IRF)-1 tumor suppressor in cervical carcinogenesis, we found that HPV E7 is functionally associated with IRF-1. Binding assays indicate a physical interaction between IRF-1 and HPV E7 in vivo and in vitro. The carboxyl-terminal transactivation domain of IRF-1 was required for the interaction. Transient co-expression of E7 significantly inhibits the IRF-1-mediated activation of IFN-beta promoter in NIH-3T3 cells. Co-transfection of E7 mutants reveals that the pRb-binding portion of E7 is necessary for the E7-mediated inactivation of IRF-1. It was next determined whether histone deacetylase (HDAC) is involved in the inactivation mechanism as recently suggested, where the carboxyl-terminal zinc finger domain of E7 associates with NURD complex containing HDAC. When trichostatin A, an inhibitor of HDAC, was treated, the repressing activity of E7 was released in a dose-dependent manner. Furthermore, the mutation of zinc finger abrogates such activity without effect on the interaction with IRF-1. These results suggest that HPV E7 interferes with the transactivation function of IRF-1 by recruiting HDAC to the promoter. The immune-promoting role of IRF-1 evokes the idea that our novel finding might be important for the elucidation of the E7-mediated immune evading mechanism that is frequently found in cervical cancer.

Specific serum IgG, IgM and IgA antibodies to human papillomavirus types 6, 11, 16, 18 and 31 virus-like particles in human immunodeficiency virus-seropositive women

To evaluate the humoral immune response to human papillomavirus (HPV) in women infected with human immunodeficiency virus (HIV), serum samples of 83 HIV-positive individuals were analysed by ELISA for specific antibodies of the isotypes IgG, IgA and IgM recognizing HPV-6, -11, -16, -18 and -31 L1 virus-like particles (VLPs). Papillomavirus-related lesions were present in 30 of 83 HIV-positive women. Twenty-one women (25%) presented with high-/intermediate-grade anogenital squamous intraepithelial lesions. PCR analysis and sequencing for HPV typing was done from biopsy specimens of 18 women; PCR-positive results were obtained in 90% of cases. In addition, HPV DNA hybrid capture assays were performed from cervical swabs of 58 HIV-positive women, 53% of whom had a positive result for high-risk HPV. Overall, positive IgG reactivity to HPV-6/-11 and HPV-16/-18/-31 was seen in 19%/31% and 49%/30%/24% of HIV-positive women, respectively. HPV-seropositivity was even higher than in 48 HIV-negative cervical intraepithelial neoplasia/cancer patients with percentages as follows: 8%/2% and 31%/15%/15%. This difference was significant for HPV-16 (P=0.046). IgA responses were comparable to IgG. IgM responses were low. The extraordinarily high rate of antibodies to the capsid protein L1 of high-risk HPVs (HPV-16, -18 and/or -31) in 58% of HIV-positive women compared to 19% (P=0.00001) of 102 healthy HIV-negative control women suggests a high lifetime cumulative exposure to HPV and increased expression of capsid proteins due to cellular immunodeficiency in HIV-infected women.

Capture ElISA and in vitro cell binding assay for the detection of antibodies to human papillomavirus type 6b virus-like particles in patients with anogenital warts

To investigate human papillomavirus (HPV) virus-like particle (VLP)-specific antibody responses among anogenital warts patients, a VLP-based capture ELISA was established. Twenty-six percent (35/134) of control subjects and 50.0% (39/78) of patients with current anogenital warts showed IgG seropositivity to HPV 6b VLPs. HPV 6b VLP-specific antibody responses recognised native VLPs only, and had no cross-reaction with HPV type 16 VLPs. No differences in reactivity were observed between L1 and L1 + L2 VLPs, suggesting that L2 contributes little to the total immunogenicity of the papillomavirus virion. A VLP-cell binding assay was also established. Some sera from patients with anogenital warts specifically inhibited VLP binding to the surface of epithelial cells, suggesting that these antibodies might be functionally neutralising. These data show that serological responses to HPV 6b VLPs were induced among some but not all patients with anogenital warts, and give a proportional estimate of infection in the community.

High-risk human papillomavirus types and squamous cell carcinoma in patients with respiratory papillomas

Respiratory papillomas (RPs) are benign, virally induced tumors of the larynx and respiratory epithelium that may obstruct the airway and tend to recur frequently. RPs are thought to be the result of infection with the human papillomaviruses (HPVs) types 6 and 11. We surveyed archival RP specimens to determine whether there were correlations of HPV type with patient characteristics or clinical course. Paraffin-embedded papilloma specimens of 45 different patients were analyzed. We assessed HPV types using the polymerase chain reaction with E6 consensus primers, hybrid capture assays (high or low risk), and dot blot hybridization of generic E6 PCR products with E6 type-specific oligonucleotide probes. The presence and type of HPV were correlated with patient data from a retrospective chart review. We found that RPs may have either low- or high-risk HPV types and some contain multiple HPV types. Respiratory infection with high-risk HPV apparently introduces a long-term risk of squamous cell carcinoma development, even in the absence of conventional cofactors. Low-risk HPV infection may also act in association with these cofactors to promote carcinogenesis. Our data also show a racial imbalance in RP that may indicate a difference in genetic resistance and/or susceptibility to HPV infection and the development of RP.

Automated in situ hybridization: diagnostic and research applications

Although in situ hybridization has been in use for almost 30 years, its technically demanding nature, the requirements for optimal tissue fixation and preservation, and the turnaround time for the experiments have prevented this technique from becoming widely used in the surgical pathology setting. The use of nonisotopic reporter molecules, the possibility of performing hybridization on archival material, and very recently, automation of the procedure have brought in situ hybridization to the forefront of diagnostic and experimental pathology. We describe our experience with nonradioactive, automated in situ hybridization, compare the technique with traditional manual procedures, and briefly outline its potential applications in diagnostic pathology and in the research setting.

The intracellular expression pattern of the human papillomavirus type 11 E1--E4 protein correlates with its ability to self associate

The function of the human papillomavirus type 11 (HPV 11) E1--E4 spliced protein is not known. E1--E4 protein in HPV-infected tissue is detected in the cytoplasm of differentiated epithelial cells and as immunoreactive bands corresponding to potential monomers, dimers and trimers in immunoblots. The yeast two-hybrid system was employed to test for self association of the HPV 11 E1--E4 protein. To confirm the results of the yeast two-hybrid experiments, coimmunofluorescence studies of a green fluorescent fusion protein (GFP-E1--E4) and a T7 epitope-tagged E1--E4 protein were performed in C33a keratinocytes. E1--E4 protein was shown to self associate in the yeast two-hybrid system, and this result was confirmed by colocalization of GFP-E1--E4 and T7-E1(wedge)E4 proteins in keratinocytes. Analysis of E1--E4 mutants established that the C-terminus was required for self association and that sequences in the N-terminus influenced the intracellular localization of E1--E4 protein. The intracellular expression patterns of GFP-E1--E4 and GFP-E1--E4 mutants were correlated with E1--E4 binding in the yeast two-hybrid system. Those E1--E4 mutants that did not self associate in the yeast two-hybrid system were detected as diffuse cellular fluorescence when expressed as GFP fusions. In contrast, GFP-E1--E4 was detected as a perinuclear aggregate. All E1--E4 mutants capable of associating with E1--E4 in the yeast two-hybrid system were detected as aggregates when expressed as GFP fusion proteins in keratinocytes.

Stringent criteria for histological diagnosis of koilocytosis fail to eliminate overdiagnosis of human papillomavirus infection and cervical intraepithelial neoplasia grade 1

Overdiagnosis of HPV infection in cervical biopsies results in increased health care costs and unnecessary surgical procedures. Stringent criteria for histological diagnosis of koilocytosis were evaluated, using molecular detection of HPV DNA (polymerase chain reaction and Southern blot hybridization) as gold standard. Colposcopic biopsy specimens from 511 patients were studied, including 76 with referral diagnoses of negative cervix and 241 with CIN 1 or koilocytosis. Referral diagnoses for low-grade lesions failed to distinguish between HPV-infected and uninfected patients. False-positive rate for prediction of HPV infection was 74.8%. Biopsy specimens reevaluated using stringent diagnostic criteria showed increasing prevalence of HPV infection among patients whose biopsy specimens showed negative (43.7%), minimal (52.4%), or definite (69.5%) features of koilocytosis (P = .001). Similarly, subjects infected with high viral load or oncogenic HPV infection were more likely to be identified (P = .004 and .04, respectively). Despite increased predictive value of stringent diagnostic criteria, significant number of patients diagnosed as having CIN 1/koilocytosis (34.0%) did not in fact have HPV infection. Because most low-grade lesions spontaneously regress, patients with histological diagnosis of CIN 1 or HPV infection should be observed for a period of several months before definitive ablative treatment is undertaken.

The 5' region of the human papillomavirus type 31 upstream regulatory region acts as an enhancer which augments viral early expression through the action of YY1

Cis-elements which control human papillomavirus early gene expression have previously been localized to sequences in the upstream regulatory region (URR) which are proximal to the E6 open reading frame. These elements include an enhancer element which functions preferentially in keratinocytes as well as promoter elements. The function of the remaining approximate 500-bp region of the URR in regulating viral expression in the high risk papillomaviruses has been largely uncharacterized. In HPV 6, a negative regulator of early expression, or silencer, has been identified in this 5' region of the URR. In this study, we have investigated the role of the 5' portion of the HPV 31 URR in regulating viral expression. Sequences in this region were found to exert a minimal negative effect on homologous or heterologous promoters. In contrast, a 128-bp sequence within this region was found to exhibit enhancer activity on heterologous and homologous promoters. This enhancer also augmented the activity of the previously identified minimum keratinocyte enhancer. The cellular factors, YY1 and TEF-1, were determined by DNase I footprint analysis and electrophoretic mobility shift assays (EMSAs) to bind the 128-bp enhancer. The binding of YY1 to two of these sites was found to be important for enhancer activity.

The high risk human papillomaviruses and oral cancer: evidence for and against a causal relationship

Oncogenic human papillomaviruses (HPVs) have been detected in oral squamous cell carcinoma (SCC). HPV16 is the most frequently detected HPV type in oral SCC and is present in up to 22% of cases, either alone or in combination with other HPV types. HPV18 is present in up to 14% of cases. HPV16 and HPV18 are present together in approximately 6% of cases. However, HPV16 and 18 are also detected in normal oral mucosae (10% and 11% of subjects, respectively). These data suggest that high risk HPV infection may be a co-factor in oral carcinogenesis and that latent HPV infection of the oral mucosa is common. A role for HPV infection in oral carcinogenesis is supported by the ability of high risk HPVs to immortalize oral keratinocytes in vitro. Immortalization may involve (i) deactivation of pre-formed tumor-suppressor proteins by viral oncoproteins, (ii) blocking of tumor-suppressor gene transcription as a result of HPV oncogene insertion or (iii) stimulation of cellular oncogene transcription by the upstream insertion of HPV-derived transcription activating sequences. Hence, infection of oral keratinocytes with high risk HPV may be involved in the pathogenesis of some oral SCCs although the evidence implicating HPV in oral carcinogenesis is, at present, mainly circumstantial.

Human papillomaviruses and cervical cancer

Molecular and epidemiological studies conducted over the last 20 years led to the recognition of certain types of human papillomavirus (HPV) as the etiological agents of cervical cancer, a very common neoplasia, particularly in developing countries. More than 70 HPVs have been described, including both cutaneous and mucosal types. About half of the known HPVs, and an even higher number of variants, have been isolated from genital mucosas. The association of certain types primarily with normal tissues and benign lesions, as opposed to cancer-associated types, has led to the concept of low and high oncogenic risk HPVs, respectively. The latter express oncogenic proteins that interfere with cell growth control functions. As a consequence of the continuous expression of these viral genomes, chromosome instability may occur, leading to fully transformed cells. Studies indicate that persistence of high-risk HPVs may determine progression to more severe stages of cervical disease, while the majority of HPV infections are transient and do not seem to be important in cervical carcinogenesis. The risk for disease progression seems also to be associated with viral burden. Prospective epidemiological studies will contribute to the knowledge of the natural history of HPV infections and provide information on the determinants of viral persistence. Data derived from these studies may define the clinical utility of HPV testing and its use in cervical cancer prevention programs.

Expression and action of parathyroid hormone-related peptide in human cervical epithelial cells

Parathyroid hormone-related peptide (PTHRP) expression and activity were analyzed in normal human ectocervical keratinocytes (HCX) and keratinocytes immortalized by transfection with human papillomavirus (HPV) types 16 and 18 DNAs. In normal cells, trans-retinoic acid (RA) and 2.0 mM Ca2+ significantly stimulated PTHRP mRNA expression and secretion and led to a significant reduction in the rate of proliferation. In contrast, the basal level of PTHRP production decreased sharply in confluent HCX, and induction by Ca2+ or exogenous growth factors was reduced or lost. After stable transfection with HPV16 and HPV18 DNAs, we observed a sharp decrease of PTHRP production in high-passage poorly differentiated HCX. Finally, addition of exogenous PTHRP-(1-141) inhibited proliferation of both normal cells and low-passage well-differentiated HPV16 immortalized cells. High-passage poorly differentiated cells were refractory to PTHRP. These results demonstrate that PTHRP production varies greatly with the degree of cell proliferation and differentiation and suggest that this peptide acts as an autocrine negative growth regulator for cervical keratinocytes.

Epstein-Barr virus-associated hepatic smooth muscle neoplasm in a cardiac transplant recipient

Host immunosuppression is increasingly recognized as a significant risk factor for the development of a primary neoplasm. Chronic immunosuppressive therapy, as used in organ transplantation, may perturb the immunosurveillance ability of the host, making the patient more susceptible to virus-associated malignancies. We have taken care of a care of a child who received an orthotopic heart transplant and who then developed both a generalized lymphoproliferative disorder and a leiomyoma of the liver a year later. Epstein-Barr virus DNA was detected in a lymph node initially and the hepatic tumor cells subsequently. The former responded to a reduction in the immunosuppressive medications and the latter responded to surgical resection. This is the first report of a hepatic smooth cell neoplasm occurring following cardiac transplant and the development of two sequential Epstein-Barr virus-associated disorders in an immunosuppressed patient.

Detection and typing of human papillomavirus in biopsy and cytological specimens by polymerase chain reaction and restriction enzyme analysis: a method suitable for semiautomation

Screening for high-risk human papillomavirus (HPV) types allows the detection of women at a high risk of cervical squamous carcinomas, thereby defining a subset of patients targeted for more intensive screening and follow-up. Thirty-four cervical biopsy specimens and isolated cells from cervical smears of normal women or women diagnosed with high-grade intraepithelial lesion (HGSIL) were screened for the presence of HPV by in situ hybridization (ISH) and/or by polymerase chain reaction (PCR). The exact HPV type was determined using a novel restriction typing method. The detection of HPV was facilitated greatly by the use of a PCR-enzyme-linked immunosorbent assay (ELISA)-based method. HPV was detected by PCR in 32% of the biopsy specimens, whereas only 23% had a positive staining by ISH. In one case, a double infection was detected by ISH as well as by PCR. In two cases, the presence of HPV was detected by both methods but the exact type was different. Analyzing cells isolated from cervical smears by the PCR-ELISA technique or by PCR followed by agarose gel electrophoresis, HPV was detected only in patients with HGSIL and not in the control group. The PCR system is more sensitive than conventional ISH, and the PCR-ELISA system presented in this study is efficient in screening large series of cytological samples. Furthermore, this system allows exact HPV typing on the microtiter plate. These innovations may allow the application of HPV detection and typing as a routine screening method to identify patients with a high risk of developing cervical neoplasia.

HPV type 16 in conjunctival and junctional papilloma, dysplasia, and squamous cell carcinoma

AIMS

To clarify the role of human papillomavirus (HPV) infection in the development of papilloma, dysplasia, squamous cell carcinoma, and basal cell epithelioma arising from the eyelids, including the tunica conjunctiva palpebrum (conjunctiva), its junction to epidemis of eyelid skin (junction), and eyelid skin.

METHODS

Sixteen cases of papilloma, four of dysplasia, four of squamous cell carcinoma, and 12 of basal cell epithelioma were examined using formalin fixed and paraffin embedded samples. Detection of HPV-DNA was performed by PCR-RFLP and in situ hybridisation (ISH) methods.

RESULTS

HPV-16 was detected in 12/16 papillomas (75%), 2/4 dysplasias (50%), and 1/4 squamous cell carcinomas (25%) but in none of the basal cell epitheliomas. No other HPV subtypes were found. ISH assay showed positive signals in only two cases of dysplasia and squamous cell carcinoma. The mean age of HPV-16 positive dysplasia and squamous cell carcinoma cases (81.7 years) was significantly higher than that of HPV-16 positive papilloma cases (p < 0.01).

CONCLUSIONS

Based on the presence of HPV-16 in both benign and malignant lesions and the age distribution, it seems likely that HPV-16 alone may be incapable of causing development of conjunctival and junctional dysplasia and squamous cell carcinoma, and that any correlation between the papilloma-squamous cell carcinoma sequence and HPV infection may be due to rare events.

Generation of entire human papillomavirus genomes by long PCR: frequency of errors produced during amplification

Recently, several improvements of traditional PCR techniques have facilitated the amplification of significantly longer DNA target sequences. Here we report an improved method for amplification of entire human papillomavirus (HPV) genomes. Using rTth DNA polymerase, XL (Perkin-Elmer, Foster City CA), and the accompanying XL PCR buffer system, we have successfully amplified 8-kb genomes from approximately 10 copies of input reference strain HPV16 DNA. This long PCR (LPCR) method was subsequently used to amplify the entire HPV16 genome from clinical specimens. The fidelity with which the rTth DNA polymerase XL amplified target sequences under our chosen amplification conditions was estimated by partial sequencing of cloned LPCR products generated from cloned reference strain HPV16 genomes. A region spanning the HPV16 E6, E7, and part of the E1 open reading frames (ORFs) was sequenced in 29 clones. A total of 33 nucleotide substitutions were observed in the 23.5 kb sequenced. This corresponds to an error frequency of approximately one error per 700 bases. Finally, LPCR methods were used to amplify entire, novel HPV genomes from clinical specimens. LPCR primer pairs were designed for amplification of seven potentially novel HPV types. Amplicons of approximately 8 kb were generated from five of the seven HPV types targeted. One of the LPCR-generated novel genomes, CP141, was subsequently cloned and a partial sequence was determined.

Molecular cytogenetics of human papillomavirus-negative cervical carcinoma cell lines

Cervical cancer is a malignancy closely associated with human papillomavirus (HPV). However, some cervical carcinomas occur in the absence of the virus. Two HPV-negative cervical carcinoma cell lines, C-33A and HT-3, were examined by G-banding and fluorescence in situ hybridization (FISH) using several whole chromosome and satellite probes. Combined conventional banding and FISH analysis significantly enhanced identification of complex and cryptic chromosome rearrangements. Common to both cell lines were translocations of chromosome 1, involving a specific site on the short arm and partial or complete loss of the short arm of chromosome 9, as well as loss of chromosome 13. The C-33A line had a relatively simple chromosomal constitution, with chromosome 1 being involved in translocations with chromosomes 9, 18, and 21. Karyotype reconstruction of G-banded and painted chromosomes indicate a net loss of DNA as a result of unbalanced translocations, which occurred only at site 9p24 and loss of one copy of chromosomes 13 and 14. In contrast, HT-3 cells had complex rearrangements and deletions of chromosomes 1p, 3p, 9p, 10q/p, 11p/q, and 17p, all regions with known tumor suppressor genes. The deletions observed in these HPV-negative cervical carcinomas will be important in delineating regions of tumor suppressor genes.

Detection of several types of human papilloma viruses in AIDS-associated Kaposi's sarcoma

Epidemiological studies indicate that acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS) may be caused by an infectious, preferentially sexually transmitted agent. Infections with human papilloma viruses are common, sexually transmitted diseases occurring frequently in homosexual men, who are also the main risk group for developing KS. In order to evaluate the possible role of HPV in the development of KS, 24 cutaneous AIDS-associated Kaposi's sarcomas were investigated by the polymerase chain reaction (PCR) and by in situ hybridization for the presence of human papilloma viruses (HPV). HPV DNA sequences were detected in 5 of 24 KS specimens, in 4 of 13 normal skin specimens from AIDS patients without KS and in 5 of 14 skin specimens of HIV-seronegative patients. For the first time, HPV types 6 and 33 were detected by PCR in KS. A higher proportion of HPV types 16/18 was found in AIDS-associated KS specimens, whereas HPV type 33 was seen more often in normal skin specimens of the control group. Apart from the known HPV types 16/18 described in KS, this study demonstrates also the presence of HPV 6 and 33 in this condition.

Development of human papillomavirus type 16 associated squamous cell carcinoma of the scrotum in a patient with Darier's disease treated with systemic isotretinoin

In contrast to squamous cell carcinoma of the penis, scrotal carcinoma has historically been associated with exposure to environmental or industrial carcinogens and has only rarely been correlated with human papillomavirus. We report on a patient with squamous cell carcinoma of the scrotum in which human papillomavirus type 16 was integrated into the tumor cell genome, suggesting a causal role of human papillomavirus in the development of squamous cell carcinoma of the scrotum. Other unique features of our case include the presence of Darier's disease, an uncommon genodermatosis, and treatment with oral retinoids, which have prophylactic value in the prevention of cutaneous malignancies.

Antibodies to human papillomavirus type 16 E7 related to clinicopathological data in patients with cervical carcinoma

AIMS

To investigate the correlation between antibodies to the transforming protein E7 of human papillomavirus (HPV) type 16 and clinicopathological indices in women with cervical squamous carcinoma.

METHODS

A synthetic peptide of the HPV type 16 E7 protein (amino acids 6 to 35) was used to screen sera from 29 children, 130 women with cervical intraepithelial neoplasia, 443 women with cervical cancer, and 222 controls, for antibodies against this viral antigen. Bivariate and multivariate analyses were used to investigate the correlation between the serological status in the pretreatment sera and clinicopathological indices (size of the lesions, histological grade, stomal infiltration, vascular invasion, and nodal spread). Survival analysis was done using the Cox regression model for all FIGO stages and stages IB and ILA.

RESULTS

Cervical carcinoma patients had a significantly higher prevalence of antibodies to synthetic peptide E7/6-35 than women with cervical intraepithelial neoplasia (17.7% v 7%, p < 0.005) or controls (17.7% v 11%, p < 0.05). Bivariate analysis of the data on the presence of anti-E7/6-35 antibodies in the pretreatment sera from these patients and clinicopathological indices showed a significant correlation between the presence of anti-E7/6-35 antibodies and the size of the lesion (p = 0.0009), histological grade (p = 0.0031), and lymph node metastasis (p = 0.01). 0.011). In addition, the Cox regression model, analysing four risk factors which can be determined before treatment, showed a significant correlation between the presence of anti-E7/6-35 antibodies and a worse prognosis (p = 0.003). Survival analysis revealed that both for all FIGO stages (p = 0.0005) and for stages IB and IIA alone (p = 0.0021), anti-E7/6-35 positive patients before treatment had a significantly shorter life expectancy.

CONCLUSIONS

The presence of antibodies against E7/6-35 in pretreatment sera from patients with cervical carcinoma correlates with the size of the lesions, lymph node involvement, and a worse prognosis.

Carcinoma of the uterine cervix associated with schistosomiasis and induced by human papillomaviruses

OBJECTIVES

To determine the presence of human papillomaviruses (HPVs) in cervical cancer among patients in Tanzania and to ascertain their prevalence in cases associated with schistosomiasis.

METHODS

In situ hybridization was applied to 31 carcinomas of the uterine cervix including 10 in which schistosomiasis co-occurred. Twenty-six cases in this series also exhibited koilocytic dysplasia.

RESULTS

Twenty-six out of 31 cases revealed a specific hybridization for HPVs with varying density and distribution. A slightly higher labeling of HPV-16 than -18 was demonstrated. All schistosomiasis-associated cancers encoded the papillomaviruses. The 31 patients were predominantly young adults, a fact that reflects sexual activity at a very young age in the ethnic communities of Africa.

CONCLUSION

These findings shed new light on the presumed etiologic implication of schistosomiasis in the genesis of cervical cancer. In the absence of HPV, schistosomiasis is not the oncogenic causative agent for carcinoma of the uterine cervix.

A two-site enzyme immunoassay for quantitation of human papillomavirus type 16 particles

A group of human papillomaviruses (HPV), in particular HPV type 16, are the major cause of anogenital dysplasias, which are precursors of anogenital cancer. The mode of transmission, extent of infectivity and natural history of infection are incompletely understood because methods to quantify shedding of viral particles have not been available. A two-site ELISA was developed to detect and quantify HPV-16 particles. Rabbits and guinea pigs were immunized with a series of peptides from the L1 and L2 capsid proteins of HPV-16. Among rabbit antipeptide sera tested for use as capture antibodies, only sera against one peptide bound detectable amounts of virus. Guinea pig antisera against several peptides were used as reporter antibodies to detect bound virus particles. If antisera against the same peptide were used both as capture antibody and reporter antibody, only intact particles were detected. Disrupted particles were quantified using antibodies against one L1 peptide as capture antibody and antibodies against other L1 peptides as reporter antibody. The lowest detectable amount of virus was 3 ng (0.06 micrograms/ml). There was no detectable cross-reaction with HPV type 6 or 11. The assay could be used both with cervical swabs in several common sample collection buffers and with surgical material solubilized in NP40-containing extraction buffers. Among 15 surgically removed condyloma acuminata, only 1 specimen was found to contain HPV-16 particles, at a concentration of 375 ng/ml (1.1 micrograms/specimen). Among 29 cervical swab samples from patients with koilocytotic atypia, 9 samples were found to contain virus. The results indicate that this assay is useful for large-scale studies on shedding of HPV particles.

Seric and local antibodies against a synthetic peptide of HPV16

An ELISA method was used to detect IgG and IgA directed against a synthetic peptide derived from the E2 ORF of the human papillomavirus (HPV) 16 in sera and in cervico-vaginal secretions from 20 women without evidence of HPV infection and from 41 women with histological diagnosis of HPV infection. The proportion of IgA positive sera (63.4% in the case-group vs. 20.0% in the control-group) and secretions (48.8% in the case-group vs. 15.0% in the control-group) was significantly higher in women with HPV infection and seemed to increase with the severity of the cervical lesion. Such a difference was not found for specific IgG. Comparing, for each patient, the antibody level in the serum and in the secretions, we found that the amount of IgA was at mean 2.4 times higher in the sera than in the secretions.

Prevalence of human papillomavirus DNA sequences in an area with very high incidence of cervical carcinoma

To improve our understanding of the relationship and possible associations between human papillomavirus (HPV) infection and the development of cervical malignancies, the presence of multiple types of HPV DNA sequences in cervical carcinoma was determined in Chinese citizens living in two different geographical locations where the incidences of cervical carcinoma are either relatively low or extremely high. HPV DNA sequences were found in 88.5% (54 of 61) of Chinese cervical carcinoma patients living in Taiwan, where the prevalence of cervical carcinoma is 23.7 per 100,000 women. In contrast, in LueYang in Shanxi province, an area with a very high prevalence of cervical carcinoma (1,026 per 100,000 women), only 57.1% (28 of 49) of Chinese cervical carcinoma patients were found to be infected with genital HPV. This result seems to suggest that either the presence of HPV may have different implications in different populations or HPV infection may not be the only factor that determines the development of cervical carcinoma, at least in certain geographical areas. Recently acquired transient or chronic persistent HPV infection may have a different outcome with regard to cervical carcinogenesis. Alternatively, other factors, such as host determinants, may play a role in the development of cervical carcinoma.

Monoclonal antibodies targeted to alpha-oligonucleotides. Characterisation and application in nucleic acid detection

The aim of the present study was to test the antigenicity of alpha-deoxyribonucleotides in order to develop a new tool for the detection of nucleic acid sequences for use in diagnostic applications. We describe four monoclonal antibodies (Mabs) which recognize alpha-deoxyribonucleotides. Two were raised against a poly(alpha-dT) sequence and specifically recognized the alpha-dT nucleotide. Two were raised against a sequence containing all four common nucleotides as alpha-nucleotides and, surprisingly, only recognized the alpha-dG nucleotide. For all four Mabs, no cross reactivity was observed with beta-oligonucleotides. These Mabs were reactive with alpha-oligonucleotide sequences whether these sequences were single-stranded or hybridized to DNA or RNA. The four Mabs were tested in a sandwich hybridization assay that consisted of an alpha-oligonucleotide (for target sequence recognition), one of the four Mabs (for recognition of the hybridized alpha-oligonucleotide), and goat anti-mouse antibody conjugated to horse radish peroxidase (HRP) (for detection). One of the monoclonal antibodies, Mab 2E11D7, was directly conjugated to HRP and used in sandwich hybridization to detect PCR fragments of HPV 18 DNA. The sensitivity of this reaction was 1 pg of plasmid DNA containing the HPV 18 fragment. The specificity of the detection was demonstrated using HPV 6/11 and 16 DNA sequences.

Urethral meatal warts in men: results of urethroscopy and biopsy

Human papillomavirus is a common sexually transmitted infection associated with cervical dysplasia. We investigated the extent of urethral human papillomavirus infection by performing urethrocystoscopy on 90 men who presented to a sexually transmitted disease clinic with external meatal warts. A total of 83 men underwent biopsies and in 49 human papillomavirus typing was done. Of 90 men with external meatal warts 75 (83.3%) had no other warts, while 15 (16.7%) also had more proximal lesions. Only 5 men (5.6%) had lesions at or beyond the pendulous urethra. Of the 90 men 12 (13.3%) had 2 warts, 3 (3.3%) had 3 warts and none had more than 3 warts. A total of 39 men had human papillomavirus type 6/11, 1 had type 31/33/35 and 9 were negative for human papillomavirus antigens. Histological evaluation of biopsies showed no dysplasia. Our study confirms that the frequency of internal urethral warts is low. Human papillomavirus infection was not associated with urethral dysplasia.

Chromosomal organization of viral integration sites in human papillomavirus-immortalized human keratinocyte cell lines

The target specificity of viral integration is essential to determining the biologic significance of this integration to various pathologic conditions, including cancer. In this study the chromosomal features of several human papillomavirus (HPV)-16 integration sites mapped by in situ hybridization in human keratinocyte lines were visualized directly by G-banding and differential labeling with bromodeoxyuridine of later replicating domains. G-negative chromosomal bands exhibiting late replication were selectively targeted by HPV-16, suggesting that the structural and functional relationship of the state of chromatin condensation and replication is critical in accessibility to virus integration.

Human papilloma virus types in routine cytological screening and at colposcopic examinations

Certain types of human papillomaviruses (HPV) play a crucial role in the development of anogenital cellular dysplasia and cancer. We have searched for a broad spectrum of HPV-types by PCR in cervical cell samples from 230 women aged 20-29 years enrolled at routine gynecological health control and 506 women referred to colposcopy due to suspected cytological changes. Thirteen percent of the health control women had HPV DNA of identified types. Half of the colposcopy patients showed benign histology with corresponding HPV DNA prevalence of 18%, while among the patients with cervical intraepithelial neoplasia between 61% and 78% had HPV DNA. Among both women with normal cytology or histology and those with various degrees of cervical dysplasia, cancer-related HPV types represented about 85% of the types found. The strong correlation between HPV infections and development of cervical dysplasia is an argument for HPV DNA testing of certain patient groups.

Analysis of human papillomavirus types in exophytic condylomata acuminata by hybrid capture and Southern blot techniques

Exophytic condylomata acuminata of the external genitalia of 40 patients were analyzed for human papillomavirus (HPV) DNA by the Southern blot and hybrid capture methods. All lesions were initially analyzed by the Southern blot method by using a mixture of HPV type 6, 11, 16, and 18 whole genomic probes. Southern blots demonstrated characteristic PstI restriction patterns of HPV type 6, 11, or 16 in all but one lesion. HPV 6 subtypes accounted for 28 of 39 HPV-positive lesions. Twenty-seven of these 28 lesions contained HPV type 6a, and 1 lesion contained HPV type 6c. Eight lesions contained HPV type 11 and three contained HPV type 16. Two of the three condylomata acuminata containing HPV type 16 were obtained from solid-organ transplant recipients receiving immunosuppressive medications. The third lesion containing HPV type 16 was a typical exophytic condyloma acuminatum from a woman with previously resected vulvar carcinoma. The hybrid capture assay detected HPV DNAs in all lesions except the Southern blot-negative lesion. Twenty-five lesions were positive for the A probe only (HPV types 6 and 11 and related types). All of these lesions were found to contain HPV type 6 or 11 sequences in the Southern blot assay. The remaining 14 lesions were positive for both the A probe and the B probe (HPV types 16 and 18 and related types). The strongest signal in these 14 lesions by the hybrid capture assay was consistent with the result of the Southern blot assay in all but one case. We conclude that (i) HPV type 6a is the most common type found in these lesions, (ii) HPV type 16 may be present more often in exophytic condylomata acuminata from immunosuppressed individuals, (iii) hybrid capture is a useful tool for documenting the presence of HPV sequences in DNAs from exophytic condylomata acuminata, and (iv) in samples containing multiple HPV types, hybrid capture allows detection of minority HPV types.

Detection of human papillomavirus infection by non-isotopic in situ hybridisation in condylomatous and CIN lesions

AIMS

To study the value of non-isotopic in situ hybridisation (NISH) in detecting human papillomavirus (HPV) infection in female genital lesions positive for the virus by conventional histology but negative by filter DNA hybridisation.

METHODS

Forty three cases, which showed the histological hallmarks of the HPV infection but produced negative results in filter dot blot hybridisation tests (Vira Pap and Vira Type kits), were identified in the course of an investigation of 304 vaginal, vulvar, and cervical samples from 267 patients. These cases were studied by NISH for the presence of HPV infection.

RESULTS

In 28 (65%) of the cases NISH gave a positive hybridisation signal. In 26 cases (96%) the signal was diffuse, and in two (4%) punctate or diffuse, representing episomal and episomal or integrated HPV DNA, respectively. In most cases only a few HPV positive cells were discernible.

CONCLUSION

NISH is a more sensitive technique than dot blot hybridisation, detecting HPV infection in most cases which show histological HPV atypia but which remain negative in filter DNA hybridisation. Thus NISH is useful as an additional technique to verify the presence of HPV in lesions which remain negative in filter hybridisation tests.