Biology and biochemistry of papillomaviruses

HPV type-specific distribution among family members and linen in households of cutaneous wart patients

Background

Common and plantar warts are caused by human papillomaviruses (HPV). Mode of transmission of wart HPVs within families is largely unknown.

Objective

To demonstrate similarity of HPV type(s) among wart cases, family members and household linen.

Methods

In a cross‐sectional study, swabs taken from 123 warts and foreheads of 62 index patients and 157 family members and from 58 kitchen towels and 59 bathroom mats were tested for DNA of 23 cutaneous wart‐associated HPV types. Generalized estimating equations (GEE) were used to estimate the chance of detecting the same HPV type as was found in the index patients on the family contacts and on the kitchen towels and bathroom mats.

Results

HPV1, HPV2, HPV27 and HPV57 were the most prevalent types in the warts of the index patients. Altogether, 60 (42.3%) of the 142 family members without warts had HPV DNA on their foreheads. When HPV1 and HPV2 were found in the warts, these types were also frequently (>50%) found on the foreheads of index patients and their family members, as well as on the kitchen towels and the bathroom mats. HPV27 and HPV57 were less frequently found (<25%) on foreheads and linen. No associations were found for age, sex and site of HPV DNA presence.

Conclusion

Dissemination of skin wart‐causing HPV types, from wart cases to household contacts and linen, such as kitchen towels and bathroom mats, is more likely for HPV1 and HPV2 than for HPV27 and HPV57. The role of towels and bathroom mats in HPV transmission deserves further investigation.

Linked Commentary A. Kreuter and U. Wieland. J Eur Acad Dermatol Venereol 2022; 36: 11–12. https://doi.org/10.1111/jdv.17820.

HPV16 E6 and E7 Upregulate Interferon-Induced Antiviral Response Genes ISG15 and IFIT1 in Human Trophoblast Cells

Human papillomavirus (HPV) is suggested to infect trophoblasts in the placenta, and HPV infections are reported to be more prevalent in pregnancies with adverse outcomes. Results are however controversial, and studies investigating the molecular consequences of placental HPV infections are lacking. We studied HPV DNA localization in the placenta in cases of spontaneous abortion/spontaneous preterm delivery as well as in elective abortion/normal full-term delivery. Using in vitro assays, we investigated downstream effects of HPV16 E6 and E7 expression in trophoblast cells at the gene expression level in order to gain increased biological insight into the interaction between HPV and the cellular host. Fluorescent in situ hybridization (FISH), combined with fluorescent immunohistochemistry (FIHC) to target the trophoblast marker CK7 clearly showed, that HPV DNA resides within syncytiotrophoblast cells in the placenta. In vitro HPV16 E6 and E7-transfected trophoblasts were analyzed by RNA sequencing, and results were validated by reverse transcription real time polymerase chain reaction (RT-qPCR) for selected genes in cell lines, as well as in patient material. We show that HPV16 E6 and E7 upregulate interferon-induced antiviral response genes ISG15 and IFIT1 in a human trophoblast cell line two-days post-transfection. This is a response that is not observed when assessing the gene expression levels of the same genes in HPV16-positive placenta samples. Investigations on viral activity find that HPV16 E6 and E7 are not transcribed in patients, possibly suggesting that HPV16 syncytiotrophoblast infection may be latent. We conclude that HPV localizes to syncytiotrophoblast cells of the placenta, and that active expression of HPV16 E6 and E7 induce an immediate interferon-induced antiviral response in trophoblast cells, which is not present in HPV-positive placenta samples, suggesting latent infection.

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.

The translational significance of epithelial-mesenchymal transition in head and neck cancer

Positive markers of epithelial-mesenchymal transition (EMT) in head and neck cancers complicate clinical management and are associated with reduced survival. We discuss recent translational discoveries in EMT and suggest additional actionable molecular pathways, biomarkers, and clinical agents.

High prevalence of cutaneous warts in elementary school children and the ubiquitous presence of wart-associated human papillomavirus on clinically normal skin

BACKGROUND

One-third of Dutch primary school children have cutaneous warts; each year around 20% of them seek medical treatment. However, little is known about the epidemiology of the types of human papillomavirus (HPV) causing these warts.

OBJECTIVES

To investigate the distribution of cutaneous wart-associated HPV types in three primary school classes by analysing skin swabs taken from warts, and the forehead, hand dorsum and sole of the foot of included children.

METHODS

Using the hyperkeratotic skin lesion polymerase chain reaction/multiplex genotyping assay, each swab sample was used to genotype for 23 cutaneous wart-associated HPV types.

RESULTS

Thirty-one (44%) of the 71 children had a total of 69 warts, with a maximum of six warts per child. In the wart swabs, HPV2, HPV27 and HPV57, members of Alphapapillomavirus species 4, were most frequently detected (27%, 32% and 14%, respectively), whereas HPV1 was only found in two plantar warts. The prevalence of HPV carriage, detected in swabs of clinically normal skin of the forehead, left hand and left sole was 80%, with the most prevalent types being HPV1 (59%), HPV2 (42%), HPV63 (25%) and HPV27 (21%).

CONCLUSIONS

Cutaneous wart-associated HPV types were highly prevalent in primary school children, but did not correlate with the HPV types in warts. In contrast to the existing literature, HPV1 was frequently detected on clinically normal skin but was much less frequent in warts.

Searching for the initiating site of the major capsid protein to generate virus-like particles for a novel laboratory mouse papillomavirus

Correctly folded virus-like particles (VLPs) of papillomavirus (PV) display conformationally dependent epitopes that are type specific, maintained on authentic virions, and induce neutralizing antibodies. Alignment of the L1 amino acid (aa) sequences of 84 PVs revealed that the lengths of their N-termini are diverse and that multiple, possible initiation methionine (met) codons exist. The L1 gene of MusPV (MmuPV1), that naturally infects immunodeficient laboratory mouse strain (NMRI-Foxn1(nu)/Foxn1(nu)), has four met codons at the 1st, 2nd, 28th, and 30th aas from its N-terminus. Of these, the 3rd and 4th mets, that are at the 28th and 30th aa position from the N-termius, respectively, are located at the position where most PVs have their first met. These two mets, located at the 9th and 11th from the YLPP conserved aas of most PVs, should be considered as consensus initiation codons of PV L1s. Three L1 proteins of MusPV, starting from the 2nd, 3rd, and 4th mets, were expressed using a baculovirus expression system and characterized for their ability to self-assemble into VLPs. While MusPV L1 proteins starting from the 2nd met expressed an L1 protein that did not fold into VLPs, the L1s starting from the 3rd and 4th mets generated correct VLPs in abundant quantities. We now conclude that the highest quantity and best quality VLPs are made from the consensus L1 met of MusPV.

Condylomata gigantea in a male transsexual

Summary

As the incidence of genital warts increases, warts arising in the mouth, throat and other sites can occasionally be seen. Condyloma gigantea in genital sites are often reported, but literature on genital warts in transsexuals is rare. We present a case of C. gigantea in a 23-year-old male-to-female transsexual, whose warts arose on the transplanted skin of a neovagina and in the perianal region. We conclude that although C. gigantea can occur in transsexuals, the best way to treat it is not clear.

Classification of the papillomaviruses--mapping the genome

Papillomaviruses form one genus of the Papovaviridae family. They share common antigenic determinants and their DNAs cross-hybridize under conditions of low stringency. The classification of papillomaviruses is at present based on the host range and the relatedness of the nucleic acids. Isolates are considered independent types if there is less than 50% cross-hybridization in the liquid phase according to a standard protocol. At least 31 human and six bovine papillomavirus types can be differentiated on this basis. The host range does not reflect the natural relationship between the viruses. Subgenera, which differ in biological properties, can be distinguished in outline. Data on overall sequence homology are insufficient for a meaningful classification because two types of virus may be closely related within one genome region and rather heterogeneous in other areas. Some new isolates appear as intermediates between previously well-separated types and complicate the system. A reasonable classification of such types of papillomavirus should be based on homologies between genes that are relevant for differences in the biology of the viruses. A functional mapping of the rather uniformly organized, colinear genomes of papillomaviruses has been started. Genetic studies with bovine papillomavirus type 1 have assigned functions in replication, transformation, gene expression and capsid synthesis to individual open reading frames.

Organization and expression of the genome of bovine papillomavirus type 1

The viral mRNAs present in C127 cells transformed by bovine papillomavirus type 1 (BPV-1) have been mapped by a variety of techniques, including S1 nuclease analysis, Northern blot analysis, primer extension and electron microscopic heteroduplex analysis. The results reveal a very complex mRNA pattern, comprising at least five types of spliced cytoplasmic mRNAs. Both unspliced and partially processed nuclear RNA species have also been identified. The transforming region of BPV-1 contains several promoter regions. A major cap site is located at coordinate 1 and another putative cap site at coordinate 31. A third candidate cap site maps around coordinate 39.

Sarcoids in captive zebras (Equus burchellii): association with bovine papillomavirus type 1 infection

Sarcoids were diagnosed in two captive zebras from different facilities. Zebra 1 (Equus burchellii boehmi) was a 4.5-yr-old, captive-born male that presented with a 9- by 7-cm inguinal mass. Seven months after surgical excision of the inguinal mass, the zebra presented with a similar lesion in the right upper eyelid that has relapsed repeatedly and has not responded to treatment including local cisplatin injections and cryosurgery. Zebra 2 (of undetermined taxon) was housed at a private wild animal farm. The zebra presented with a single, raised, 2.5- by 2.0- by 2.0-cm, ulcerated mass on the nose, and surgical excision was curative. Histologically, the three masses consisted of a dermal, compact, nonencapsulated, poorly demarcated neoplasm composed of well-differentiated spindle cells arranged in streams and whorls and accompanied by moderate epidermal hyperplasia with long rete pegs. On the basis of the morphologic resemblance to the unique equine cutaneous neoplasm, "sarcoid" was diagnosed. This is the first description of sarcoids in captive zebras. Association with bovine papillomavirus (BPV) type 1, as it occurs in horses, was demonstrated by polymerase chain reaction, nucleic acid sequencing, and in situ hybridization (ISH) on paraffin-embedded tissues from the inguinal mass of zebra 1. Sequencing revealed 98% identity of the 244-bp fragment with BPV type 1. The ISH for BPV type 1 DNA intensely stained the nuclei of neoplastic mesenchymal spindle cells. The sites and the clinical behavior of the sarcoids in these zebras are similar to those described in horses.

Development and evaluation of a highly sensitive human papillomavirus genotyping DNA chip

OBJECTIVES

Test of human papillomavirus (HPV) is a useful adjunctive tool of Pap smear to screen cervical cancer. We have developed a novel HPV genotyping DNA chip arrayed by multiple oligonucleotide probes of both L1 and E6/E7 gene sequence of 42 types of anogenital HPV.

METHODS

Consensus PCR products of L1 and E6/E7 gene sequences of HPV are hybridized to arrayed probes on the HPV chip and HPV genotypes are identified by fluorescence scanner. We have comparatively analyzed the value of HPV DNA chip and DNA sequencing in 100 cervical cancer tissues.

RESULTS

Overall, 98 cervical cancer tissues were found to harbor DNA sequences of high-risk type HPVs, of which 88 (89.8%) were detected by PCR-sequencing of L1 alone, 98 (100%) by PCR-sequencing of both L1 and E6/E7, and 98 (100%) by HPV DNA chip, respectively. All of the genotypes of HPV detected on sequencing analysis were also found on DNA chip analysis. HPV DNA chip was superior to direct DNA sequencing in detection of mixed infection.

CONCLUSIONS

These results suggest that HPV DNA chip analysis in the present study is highly accurate for detection and genotyping of HPV and may have potential value as a robust, high-throughput screening test of uterine cervix cancer.

Human papillomavirus type 31b infection of human keratinocytes does not require heparan sulfate

Oncogenic human papillomaviruses (HPVs) are difficult to study experimentally as they replicate at low levels in vivo. This has precluded the purification of high-risk HPV virions from in vivo lesions. Virus-like particles (VLPs) and pseudovirions from low- and high-risk HPV types can emulate various aspects of HPV virion attachment and infections. These studies suggest that HPV infection is mediated by alpha6-integrin and/or heparan-sulfonated receptors. However, whether VLPs and pseudovirions accurately reflect the infection process of HPV virions has not been verified. We generated infectious HPV31b virions from organotypic (raft) tissues and performed experimental infections in a variety of cells. Successful infection following viral attachment, internalization, and nuclear transport was assayed by detecting newly synthesized, spliced HPV transcripts using reverse transcription (RT)-PCR or RT-quantitative PCR. Most human epithelial cells were infected with HPV31b at a multiplicity of infection as low as 1 to 10 viral genome equivalents per cell. HPV31b infection was detected in other cell lines, including COS-7 monkey kidney cells, but higher viral multiplicities of infection were required. Heparin preparations of various molecular weights or heparinase I treatment of cells prevented HPV31b infection of COS-7 cells and C-33A human cervical cancer cells in reproducible and dose-dependent manners. However, these reagents were unable to block infection of human keratinocytes, including HaCaT and N/TERT-1 cells and low-passage human foreskin keratinocytes. These data suggest that HPV31b infection of human keratinocytes, the natural host cell for HPV infections in vivo, does not require a heparan-sulfonated receptor, whereas heparan sulfate is important for infection of some other cells.

Detection of papillomavirus-DNA in mesenchymal tumour cells and not in the hyperplastic epithelium of feline sarcoids

We examined 12 formalin-fixed paraffin-embedded feline skin tumours which had the histopathological features of fibropapillomas for the presence of papillomavirus (PV) DNA using touchdown polymerase chain reaction (PCR), DNA sequencing and nonradioactive in situ hybridization. Nine of the tumours contained a 102-bp PCR product demonstrated using consensus PV primers that amplify a portion of the L1 gene. The nucleotide sequences are closely related, but not identical to that of ovine PV type 2, rabbit oral PV and reindeer PV. The deduced amino acid sequences had strong homologies with the major capsid protein L1 of deer PV, bovine papillomavirus (BPV) 1 and BPV 2, and European elk PV. Although PV antigens were not detected in any of the tumours by immunohistochemistry, PV DNA was demonstrated in individual mesenchymal cells or cell nests of 4/12 tumours by in situ hybridization. A nonproductive infection of mesenchymal fibroblast-like tumour cells with a papillomavirus would explain the lack of PV antigen expression and the absence of PV DNA in the hyperplastic epithelium. Because these tumours and their pathogenesis are similar to equine sarcoids, we suggest that they should be reclassified as 'feline sarcoids' instead of fibropapillomas.

Infectious human papillomavirus type 31b: purification and infection of an immortalized human keratinocyte cell line

Human papillomaviruses (HPVs) are aetiological agents of human malignancies, most notably cervical cancers. The life-cycles of HPVs are dependent on epithelial differentiation, and this has impeded many basic studies of HPV biology. The organotypic (raft) culture system supports epithelial differentiation such that infectious virions are synthesized in raft tissues from epithelial cells that replicate extrachromosomal HPV genomes. The CIN-612 9E cell line maintains episomal copies of HPV type 31b (HPV31b), an HPV type associated with cervical cancers. Many previous studies, including our own, have focused on characterizing the later stages of the HPV31b life-cycle in CIN-612 9E raft tissues. In this study, we have used the raft system to generate large numbers of HPV31b viral DNA (vDNA)-containing particles. We found a biologically contained homogenization system to be efficient at virion extraction from raft epithelial tissues. We also determined that vDNA-containing particles could be directly quantified from density-gradient fractions. Using an RT-PCR assay, the presence of newly synthesized, spliced HPV31b transcripts was detected following HPV31b infection of the immortalized HaCaT epithelial cell line. Spliced E6 and E1( wedge )E4 RNAs were detected using a single round of RT-PCR from cells infected with a dose as low as 1.0 vDNA-containing particle per cell. Spliced E1*I,E2 transcripts were found in cells infected with an HPV31b dose as low as 10 vDNA-containing particles per cell. Infectivity was blocked by HPV31 antiserum, but was not affected by DNase I. This work lays a foundation for a detailed analysis of the early events in HPV infection.

Generation and characterization of monoclonal antibodies against the E6 and E7 oncoproteins of HPV

Generation of three monoclonal antibodies (MAbs) to the major oncoproteins of human papillomavirus (HPV) was accomplished by an intense prime/boost regimen. Mice were primed with expression vectors expressing either the E6 or E7 oncoproteins of HPV-16 followed by boosting with a vaccinia virus construct and a replication-defective E1-deleted adenoviral recombinant of the human strain 5, and last, with baculovirus-derived HPV-16 E6 and E7 proteins in incomplete Freunds' adjuvant. Splenocytes were then fused with a myeloma cell line. The vaccination protocol generated one anti-E7 MAb of the IgM isotype and two anti-E6 MAbs of the IgG1 subisotype. The MAbs were tested for functionality in standard laboratory assays and found to detect the E6 and E7 proteins, respectively. The E7 MAb cross-reacted with the HPV-1a E7 oncoprotein. The binding sites of the MAbs were mapped to defined regions of each viral protein.

Low level expression of human papillomavirus type 16 (HPV16) E6 in squamous epithelium does not elicit E6 specific B- or T-helper immunological responses, or influence the outcome of immunisation with E6 protein

Mice transgenic for E6/E7 oncogenes of Human Papillomavirus type 16 display life-long expression of E6 in lens and skin epithelium, and develop inflammatory skin disease late in life, which progresses to papillomata and squamous carcinoma in some mice. We asked whether endogenous expression of E6 induced a specific immunological outcome, i.e. immunity or tolerance, or whether the mice remained immunologically naïve to E6. We show that prior to the onset of skin disease, E6 transgenic mice did not develop a spontaneous E6-directed antibody response, nor did they display T-cell proliferative responses to dominant T-helper epitope peptides within E6. In contrast, old mice in which skin disease had arisen, developed antibodies to E6. We also show that following immunisation with E6, specific antibody responses did not differ significantly among groups of E6-transgenic mice of different ages (and therefore of different durations and amounts of exposure to endogenous E6), and non-transgenic controls. Additionally, E6 immunisation-induced T-cell proliferative responses were similar in E6-transgenic and non-transgenic mice. These data are consistent with the interpretation that unimmunised E6-transgenic mice that have not developed inflammatory skin disease remain immunologically naïve to E6 at the B- and Th levels. There are implications for E6-mediated tumorigenesis in humans, and for the development of putative E6 therapeutic vaccines.

A novel and rapid PCR-based method for genotyping human papillomaviruses in clinical samples

Many human papillomavirus (HPV) genotypes are associated with cervical carcinoma. We demonstrate the utility of an innovative technique for genotyping of HPV in cervical tissue samples. This method provides an accurate means of identification of the specific HPV genotypes present in clinical specimens. By using the MY09-MY11 and the GP5(+)-GP6(+) consensus primer pairs, HPV sequences were amplified by nested PCR from DNA isolated from cervical smear samples. This led to the production of an approximately 140-bp PCR product from the L1 (major capsid) gene of any of the HPVs present in the sample. PCR was performed with a deoxynucleoside triphosphate mixture which resulted in the incorporation of deoxyuridine into the amplified DNA product at positions where deoxythymidine would normally be incorporated at a frequency of about once or twice per strand. Following the PCR, the product was treated with an enzyme mix that contains uracil N-glycosylase (UNG) and endonuclease IV. UNG removes the uracil base from the nucleotide, and endonuclease IV cleaves the phosphodiester bond at this newly formed abasic site, producing fragments of various sizes. By having end labeled one of the amplification primers, a DNA ladder which is analogous to a "T-sequencing ladder" was produced upon electrophoresis of the products. By comparing this T-sequencing ladder to the known sequences of HPVs, the genotypes of unknown HPV isolates in samples were assigned. Data showing the utility of this technique for the rapid analysis of clinical samples are presented.

Juvenile onset recurrent respiratory papillomatosis: possibilities for successful antiviral therapy

Recurrent respiratory papillomatosis (RRP) is a potentially devastating disease that can have significant morbidity, and can even result in mortality due to airway compromise or, less commonly, malignant transformation. Two distinct types of RRP exist: adult-onset RRP (AO-RRP) and juvenile-onset RRP (JO-RRP). Acquisition of human papillomavirus (HPV), the causative agent of RRP, is believed to occur in the peripartum period in the case of JO-RRP, with disease symptoms (primarily hoarseness) becoming apparent during the first several years of life. Treatment currently consists of surgical debulking of the papillomas to relieve airway obstruction. However, numerous antiviral therapies have also been evaluated, albeit primarily under uncontrolled settings. This article will review the biology, natural history and management of HPV infection, with particular emphasis on JO-RRP.

Digestive System 1

This chapter deals with the digestive system. The major and minor salivary glands and their secretions also represent and integral part of the protective mechanism of the oral cavity, and derangement of saliva production may lead to loss of integrity of the oral mucosa. Drug-induced abnormalities of taste sensation are also well-described phenomena occurring in man although human studies are necessary for the detection of these effects. Inflammation of the oral cavity may involve the buccal mucosa, the gingiva (gingivitis), the tongue (glossitis), and the peridontal tissues (peridontitis). Therapeutic agents can induce inflammatory lesions in the tongue. Moreover, a protective layer of mucus, a visco-elastic material containing high molecular weight glycoproteins produced by the major and minor salivary glands, covers the stratified squamous mucosa of the oral cavity. Salivary secretions also possess digestive enzyme activity although in herbivores and carnivores, it is usually low in contrast to high digestive enzyme activity in omnivorous species.

Human papillomavirus and mixed epithelial tumors of the endometrium

Strong epidemiological evidence links human papilloma viruses (HPV) with the development of cervical intraepithelial neoplasia (CIN) and invasive cancers of the uterine cervix. The localization of HPV DNA sequences high up in the female genital tract (in benign and malignant lesions) is not that uncommon, but its precise significance is uncertain. In particular, the detection of HPV DNA sequences by polymerase chain reaction (PCR) needs careful interpretation, because the source of the amplicon may emanate from tumor cells, direct contamination from the cervix, or possibly from extratumoral sites in the endometrium. We have previously reported the identification of koilocyte-like changes in the squamous epithelium of some endometrial adenoacanthomas. Adenoacanthomas (adenocarcinoma with squamous metaplasia) are mixed epithelial tumors arising in the endometrium composed of malignant glandular areas admixed with benign metaplastic squamous epithelium. The rarer adenosquamous carcinoma containing both malignant glandular and squamous areas is also described. The origin of benign/malignant squamous epithelial islands in endometrial tumors has been the subject of speculation, with some investigators considering an origin from metaplastic glandular endometrial cells. In this study, we examined 10 normal endometrial samples, 20 adenocarcinomas, 41 adenocarcinomas with squamous metaplasia, and two adenosquamous carcinomas, (including control cervical material where possible) for the presence of HPV DNA sequences using nonisotopic in situ hybridization (NISH), type-specific HPV PCR, general primer PCR (to detect sequenced and unsequenced HPVs), and PCR in situ hybridization (PCR-ISH). We did not identify HPV DNA sequences in normal endometrial tissue. In adenocarcinomas (endometrioid type), HPV was only identified in 2 of 20 cases by PCR, both of which were HPV 11 positive. We were unsuccessful in identifying HPV in endometrial carcinomas by NISH or by PCR-ISH, raising the possibility of contamination from the cervix in the two positive cases. In adenoacanthomas, a low-risk HPV type (HPV 6) was found in 19 of 41 cases. NISH signals were intranuclear in location in squamous regions of adenoacanthomas. Additional positive nuclei were uncovered using PCR-ISH, which increases the sensitivity of standard NISH detection. HPV DNA sequences were located in some malignant endometrial glandular epithelial cells, but this accounted for a minority of samples. HPV DNA sequences were not detected in extraepithelial sites. Mixed infection by two different HPV types was identified in two cases. Most cases showed similar HPV types in cervical and endometrial lesions, although discordant cases were uncovered. In adenosquamous carcinomas, one case showed mixed infection with HPV 6 and 33 by PCR. The apparent segregation of low-risk HPV type (HPV 6) with benign squamous metaplastic epithelium in adenocarcinoma with squamous metaplasia, and high-risk type (HPV 33) with malignant squamous epithelium in adenosquamous carcinoma, raises important questions in relation to the role of HPVs in mixed epithelial tumors of the endometrium and their interplay in the pathogenesis of squamous metaplasia at extracervical sites.

Presence of papillomavirus-like DNA sequences in cutaneous fibropapillomas of the goat udder

Papillomatous lesions were isolated from the mammary skin of goats and examined for evidence of papillomavirus (PV) infection by various criteria, including gross morphology, histology and DNA hybridization. Although some lesions showed gross papillomatous morphological and histological features similar to those caused by papillomavirus in other species, no viral particles were detected. Reverse slot hybridization revealed cross-hybridization between DNA extracted from goat mammary papillomas and human papillomaviruses (HPV). Southern blot, using ovine papillomavirus (OPV) and bovine papillomavirus type 5 (BPV 5) DNA probes under conditions of reduced stringency (Tm -40 degrees C), detected homologous sequences in 40% of the biopsies. DNA fragments corresponding probably to a monomeric form (7000-8000 bp) of an unknown papillomavirus genome were detected. This study provides evidence for the existence of papillomavirus-like sequences in caprine mammary papillomas and suggests that a papillomavirus is likely to be involved in the development of precancerous lesions of goat mammary skin.

Use of interferon-alpha in laryngeal papillomatosis: eight years of the Cuban national programme

Laryngeal papillomatosis is one of the first diseases where interferon (IFN) was found to be effective. In 1983, a programme for the treatment of all such cases started in Cuba. Up to December 1991, 125 patients (92 children, 33 adults) have been treated: 102 with leucocyte IFN-alpha, 12 with recombinant IFN-alpha-2b, and 11 have received both preparations. Case management consisted of surgical removal of the lesions followed by an IFN schedule starting with 10(5) IU/kg of weight in children or 6 x 10(6) IU in adults, i.m. daily. The dose was progressively reduced, as long as no relapses occurred. At the end of the one-year schedule the doses were reduced to 5 x 10(4) IU/kg in children or 3 x 10(6) IU in adults, weekly. If there was a relapse, it was removed surgically and the patient returned to a higher dose level. Most cases (89; 71 per cent) have not relapsed after the treatment; 60 of them have been followed for more than three years. In those with relapses, the frequency of recurrence decreased in all but four patients. The treatment seemed to be more effective if initiated less than three months after the disease onset. The tracheostomy could be removed in five out of seven patients who needed it before the IFN treatment and was necessary in only three new cases during IFN treatment. In two of these, decannulation was possible later on. In a total of 14 patients relapses persisted after several cycles of IFN treatment. They were considered resistant to such treatment. No severe side effects were reported. The most frequent ones were fever, drowsiness, increased bronchial secretion, chills and headache. The establishment of this programme has maintained the disease under control in Cuba.

Immortalization of differentiated human keratinocytes by human papillomavirus (HPV) 16 DNA

Human papillomavirus (HPV) 16 is strongly implicated as having an etiologic role in cervical carcinoma. Human basal keratinocytes have been used in most HPV transformation studies, and transformed cells have exhibited undifferentiated characteristics. However, tumor cells in cervical squamous cell carcinoma are differentiated to certain degrees. Therefore, we hypothesize that HPV may transform not only basal cells but also differentiated keratinocytes. Human keratinocytes isolated from neonatal foreskin were induced to differentiate by treatment with 2 mM Ca2+ for various times (24, 48, 72 and 96 h) and were transfected with HPV 16 DNA. After G418 selection and repeated subculture, HPV 16-transformed cells were derived from each group of the Ca(2+)-treated and untreated cells. HPV DNA was detected in the transformed cells by polymerase chain reaction (PCR). Southern analysis and two-dimensional gel results indicated that HPV 16 DNA had been integrated into the chromosomes. The HPV 16-transformed cells exhibited an indefinite lifespan and were not tumorigenic in nude mice. They also showed the morphology and expressed the markers of differentiated keratinocytes. This study showed that differentiated human keratinocytes could be immortalized by HPV 16, and this may be a better model for cervical carcinomas in humans.

Human papillomavirus-associated oral epithelial dysplasia (koilocytic dysplasia): an entity of unknown biologic potential

Intraepithelial neoplasia of the female genital tract has long been associated with human papillomavirus infection. To date, there have been no previously published studies of oral dysplasia that have identified light microscopic features predictive of the presence of human papillomavirus. We identified a variant of oral epithelial dysplasia, koilocytic dysplasia, that exhibited light microscopic features suggestive of HPV infection. To determine if these microscopic features were specifically correlated with human papillomavirus infection, DNA in situ hybridization for human papillomavirus 6/11, 16/18, and 31/33/51 was performed on 31 lesions diagnosed histologically as koilocytic dysplasia. Seventeen matched control cases of conventional oral epithelial dysplasia were also analyzed for human papillomavirus. Human papillomavirus DNA was detected significantly more often (p < 0.001) in koilocytic dysplasia (80.6%) than conventional oral epithelial dysplasia (0.0%). Positive cases of koilocytic dysplasia contained either intermediate-risk (31/33/51) or high-risk (16/18) human papillomavirus types whether or not they contained low-risk human papillomavirus types (6/11). The histologic and clinical presentation of koilocytic dysplasia was unique. Lesions demonstrated koilocytes and other microscopic characteristics of human papillomavirus infection, as well as features of conventional epithelial dysplasia. A striking male predominance was noted, as was a relatively young average age of presentation (39.0 years). On the basis of our preliminary analysis, we conclude that oral koilocytic dysplasia represents a unique pathologic entity and that the presence of human papillomavirus can be predicted on light microscopy with at least 80% accuracy. The clinical significance and potential for malignant transformation of koilocytic dysplasia remain to be investigated.

Incidence of human papilloma virus in patients with invasive cervical carcinoma

The dot-blot hybridization of biotin-dUTP-labeled HPV-16 DNA with genomic DNA extracted from biopsies taken from patients with invasive carcinoma and abnormal cytology showed the presence of HPV-DNA in 88% and 80% cases under relaxed conditions and 40% and 20% cases under stringent conditions of hybridization, respectively. Southern blot revealed the HPV-DNA in randomly integrated form in two cases and in episomal form in the other two.

Verrucous squamous cell carcinoma of the larynx: diagnostic and therapeutic considerations

The clinical findings, histopathology, management and outcome of 31 patients with verrucous squamous cell carcinoma of the larynx (VSCC) are discussed. Laryngeal VSCC is a rare, highly differentiated variant of SCC and has specific morphological features and clinical behavior. A close liaison between the laryngologist and pathologist is needed to formulate a correct diagnosis, because this tumor appears to be malignant clinically and histologically benign. A low-power magnification of multiple large specimens, including the deep margins of the lesion, is required in order to differentiate VSCC from keratosis, verruca vulgaris or SCC with verrucous appearance, and to detect underlying microscopic foci of invasive SCC within or adjacent to a verrucous carcinoma. Long-lasting hoarseness was the most common symptom as the glottic region was the most common site of VSCC. Presumed clinically positive N1 lymph nodes were observed in the necks of 7 patients, but none had metastatic disease on histopathological study. Surgery alone was the most effective form of treatment, as it allowed a good outcome of all treated patients. Surgery plus radiotherapy was associated with an early recurrence and a poor outcome in 2 of 7 patients treated. The generally "benign" behavior of VSCC allows for conservative surgery, with complete endoscopic resection using the carbon dioxide laser representing a more conservative surgical approach. Neck dissection is not indicated due to the non-metastatic behavior of this tumor.

[The pediatrician, sexual abuse and anogenital warts in prepuberty]

The increase of incidence in human papillomavirus infection in population has favored the more frequent appearance of anogenital warts in children. Types 6 and 11 are the most frequently associated to this pathology. Though sexual transmission is common, with a very lengthy incubation period, it is not the only way. Sexual abuse is always a possible source of infection and should be excluded in all cases. An actuation protocol has to be established for the pediatrician depending on the clinical, epidemiological and the social characteristics.

A vaccine conjugate of 'ISCAR' immunocarrier and peptide epitopes of the E7 cervical cancer-associated protein of human papillomavirus type 16 elicits specific Th1- and Th2-type responses in immunized mice in the absence of oil-based adjuvants

TraT protein, known as ISCAR (= Immunostimulatory Carrier), is one of a family of integral membrane proteins (Imps) of Escherichia coli representing powerful carrier molecules which when injected into experimental animals generate substantial antibody and T proliferative responses to molecules conjugated to it. We extend these findings to show that ISCAR functions to stimulate Th1- and Th2-type responses, including specific cytotoxic T cells and tumour protection. We report here that by conjugating to ISCAR a 19mer peptide containing linear B epitopes, a T helper (Th) epitope, and a H-2b-restricted T cytotoxic (CTL) epitope of E7 protein of human papillomavirus type 16 (HPV16), and immunizing C57B1/6 (H-2b) mice, we elicited (i) specific IgG2a and IgG1 antibodies; (ii) IL-2 and IL-4 production by specifically recalled lymph node cells in vitro; (iii) cytotoxic T lymphocytes which specifically killed both E7 peptide-pulsed, and whole E7 gene-transfected tumour target cells; and (iv) in vivo protection against an E7 gene-transfected tumour cell inoculum. These findings have implications for the design of vaccines to stimulate immune responses to endogenously processed target antigens (e.g. tumour-associated antigens) without the unwanted side effects of oil-based adjuvants. In addition they support the case for a E7-targeted therapeutic vaccine for HPV-associated human cervical cancer.

Association of human papillomavirus with malignant and premalignant lesions of the uterine endometrium

The possible association of human papillomavirus (HPV) with endometrial hyperplasia and endometrial adenocarcinoma was investigated. DNA from frozen tissues of 30 endometrioid carcinomas of Japanese patients was tested for HPV DNA by Southern blot hybridization analysis. Screening with HPV type 58 probe under low stringency conditions showed the presence of HPV DNA in two of 30 endometrioid carcinomas. High stringency hybridization identified HPV type 16 in the two positive specimens. The presence of HPV was further analyzed by polymerase chain reaction (PCR)-Southern blot analysis of DNA from archival tissue blocks of the initial 30 endometrioid carcinomas as well as an additional 17 endometrioid carcinomas and 13 atypical hyperplasias of the endometrium from Japan and 38 endometrioid carcinomas from the United States. Polymerase chain reaction amplification using type 16-specific HPV primers for a portion of the E6 open reading frame was positive in six of 47 (13%) endometrioid carcinomas from Japan, including two in which HPV 16 was not detected by Southern blot analysis and two of 38 (5%) endometrioid carcinomas from the United States. Polymerase chain reaction amplification using L1 consensus sequence primers was positive for HPV in two of 13 (15%) endometrial hyperplasias, 13 of 47 (28%) endometrioid carcinomas from Japan, and six of 38 (16%) endometrioid carcinomas from the United States. Slot blot hybridization identified HPV type 16 in seven of the L1 PCR products, including all but one specimen testing positive for HPV type, 16 using E6 type specific primers. In situ hybridization was positive for HPVs 16/18 in glandular epithelial tumor cells in six of the PCR-positive specimens. An additional specimen showed staining for HPVs 16/18 in acellular luminal debris in association with squamous metaplasia of the tumor, but staining was negative in the glandular cells of the tumor. Human papillomavirus was not detected by in situ hybridization in the remaining specimen, which was PCR positive for HPV 16. In situ hybridization was weakly positive for HPVs 31/33/35 in one specimen and was weakly positive for HPVs 6/11 in benign endometrial epithelial cells but not in tumor cells of another specimen that tested positive for HPV by L1 PCR. Two dimensional gel electrophoresis performed on two specimens showed that HPV DNAs were integrated into cellular DNA with no episomal coexistence. These findings suggest that HPV, especially HPV 16, may play an etiologic role in a fraction of endometrioid adenocarcinomas.

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.

Laryngeal papillomatosis with subsequent development of papillomata in the paranasal sinuses--is it seeding by intubation?

Concern has been expressed regarding the seeding of viral DNA, in laryngeal papillomatosis, to other sites in the respiratory tract during treatment. Controversy exists regarding the concept of seeding by the laser plume. However, instrumentation and anaesthetic intubation are also strongly implicated in seeding DNA to the proximal respiratory tract. No cases of recurrent laryngeal papillomatosis and subsequent papilloma in the paranasal sinuses have been reported.

The genomes of the animal papillomaviruses European elk papillomavirus, deer papillomavirus, and reindeer papillomavirus contain a novel transforming gene (E9) near the early polyadenylation site

We report that the genomes of reindeer papillomavirus (RPV), European elk papillomavirus (EEPV), and deer papillomavirus (DPV) contain a short conserved translational open reading frame (ORF), E9, which is located between the E5 ORF and the early polyadenylation site. In RPV, DPV, and EEPV, E9 ORFs have the potential to encode extremely hydrophobic polypeptides of approximately 40 amino acids. In mouse C127 cells transformed by EEPV and RPV, there exists a unique, abundant mRNA species of approximately 700 nucleotides which has the capacity to encode an E9 polypeptide. This mRNA is transcribed from a previously unrecognized promoter at position 4030 in the EEPV genome. The EEPV E9 ORF exhibits weak transforming activity in C127 cells and primary rat embryo fibroblasts. We also show that EEPV E5 is the major oncogene in the EEPV genome when assayed in C127 cells, although it is less efficient in transformation than the E5 genes of bovine papillomavirus type 1, DPV, and RPV.

Low-affinity E2-binding site mediates downmodulation of E2 transactivation of the human papillomavirus type 8 late promoter

The constitutively active promoter P7535 of the epidermodysplasia verruciformis-associated human papillomavirus type 8 (HPV8) is transactivated by the viral E2 protein. The distribution of potential E2-binding sites (ACCN6GGT) in the viral transcription control region is highly conserved among epidermodysplasia verruciformis-associated human papillomaviruses and differs completely from that of other papillomaviruses. To investigate the role of E2-binding sites P0 to P4 in P7535 regulation, we analyzed their binding affinities in gel retardation experiments using a full-length HPV8 E2 protein expressed from a recombinant baculovirus. Binding site P1 within a transcriptional silencer showed the highest affinity, followed by P0 within the L1 gene and P3 downstream of P7535. P2, 33 nucleotides upstream of the mRNA cap site, and P4 were very weak binders. There is some indication that the number of A/T pairs in the nonconserved core of the recognition sequence is critical for the binding of HPV8 E2. Transient transfection experiments were carried out with an HPV8 E2 expression vector and reporter plasmids containing mutated E2-binding sites in the context of the HPV8 regulatory region. The knockout of the strongest binding site P1 sufficed to clearly diminish transactivation. P0, P3, and P4 mutations had little effect on their own, whereas double mutations P01 and P34 strongly reduced E2 inducibility. Both mutations in P2 severely affected constitutive promoter activity but had opposite effects on transactivation. They revealed an inverse correlation between E2-binding strength and the extent of E2 transactivation. This finding suggests that P2 mediates a negative control of P7535 by E2, counteracting E2 transactivation exerted via the four distal E2 target sequences.

Cloning and sequencing of the L1 gene of canine oral papillomavirus

Canine oral papillomavirus (COPV) DNA was isolated from two different sources. One of these DNAs was molecularly cloned and its physical map was determined. Hybridization analyses using subgenomic fragments of bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 16 (HPV16) as probes revealed that the cloned COPV shared moderate homology within the E1 and L1 regions of BPV-1 and HPV16, whereas homology in other regions of BPV-1 and HPV16 was low. The putative L1 gene of COPV was sequenced and several conserved regions, including antigenic epitopes which are common in other known papillomaviruses, were analyzed.

Transcriptional silencer of the human papillomavirus type 8 late promoter interacts alternatively with the viral trans activator E2 or with a cellular factor

The noncoding region of the highly oncogenic, epidermodysplasia verruciformis-associated human papillomavirus type 8 contains a negative regulatory element (NRE). Quantitative RNase protection analysis confirmed that the NRE sequence acts as a silencer of transcription. A 38-bp sequence upstream of late promoter P7535 down-regulated expression from the homologous P7535 promoter, as well as the heterologous tk gene promoter, independently of its orientation relative to the test promoters. It also reduced gene expression when cloned downstream of the transcription units. Transient expression assays with keratinocytes and fibroblasts of epidermodysplasia verruciformis patients and controls demonstrated that the NRE activity is not cell specific. Gel retardation tests suggested that NRE specifically interacts with only one nuclear factor. Mutational analysis identified three NRE mutants which no longer formed a detectable DNA-protein complex but still repressed transcription, indicating that protein-DNA interaction is not relevant for the silencer function. The NRE contains a binding site of viral trans activator protein E2. It was shown that expression of E2 overrides the inhibitory effect of the NRE sequences. Binding of E2 and that of the cellular factor were mutually exclusive. The bifunctional nature of NRE acting as a silencer and a target site for viral trans activator E2 offers an interesting opportunity to regulate the switch from early to late transcription in the human papillomavirus life cycle.

Butchers' warts: no evidence for person to person transmission of HPV7

The distribution of warts due to HPV7 in workers in six abattoirs and 103 retail and wholesale butcheries has been studied to determine whether the high prevalence of HPV7 in the meat trade is the result of enhanced person to person transmission, or whether it is a ubiquitous virus which is activated by an unknown factor in meat. Warts were detected in 164 of 486 men. Scrapings were taken from 156 men, and HPV DNA was found in 112 samples, 74 of which contained HPV7. HPV7 was found in 36 workplaces, and there was no evidence of clustering of cases, as would be expected if person to person transmission was occurring in the workplace. This suggests that HPV7 is widely distributed in the community, but only causes clinical disease under specific conditions. We suggest that some unknown factor in meat enhances viral replication.

A high association of oncogenic human papillomaviruses with carcinomas of the female urethra: polymerase chain reaction-based analysis of multiple histological types

Using polymerase chain reaction with type-specific human papillomavirus type 16 and 18 primers, and general primers screening for 9 other genotypes, we analyzed archival surgical specimens of urethral carcinoma from 18 women (17 with invasive cancer and 1 with carcinoma in situ). Human papillomavirus was detected in invasive urethral carcinoma specimens from 10 of 17 women (59%) and in the patient with carcinoma in situ. Human papillomavirus type 16 was found in 8 patients with invasive carcinoma (47%) and 1 with carcinoma in situ, and general primer polymerase chain reaction demonstrated human papillomavirus that could not be typed in 2 patients (12%). Type 16 was detected in metastases from 4 patients; complete concordance for the presence of human papillomavirus in primary and metastatic disease was noted. Eight of 10 women with squamous cell carcinoma and both with transitional cell carcinoma harbored human papillomavirus; 5 women with undifferentiated carcinoma or adenocarcinoma were all negative for human papillomavirus. Concurrently excised cervical tissue was available from 5 patients; 1 had cervical carcinoma in situ positive for human papillomavirus of the same type as the urethral carcinoma. These findings strongly suggest that human papillomavirus, particularly type 16, is associated with a substantial number of carcinomas of the female urethra but a stratification of specific histotypes associated with human papillomavirus may exist.

Cutaneous warts in butchers

Several studies have indicated a high prevalence of hand warts in meat handlers, although the reasons for this are not clear. The high prevalence may be partly due to HPV7, a virus found almost exclusively in meat handlers, but the source of HPV7 is not known. We have carried out a cross-sectional survey of hand warts in male meat workers and controls from other occupational groups, to investigate the reasons for the high prevalence of warts, and particularly of HPV7, in butchers. We studied 240 abattoir workers, 246 retail and wholesale butchers, 308 engineering fitters and 292 office workers. Each subject was interviewed using a standard questionnaire, and his hands were examined by a dermatologist. Scrapings from the warts were tested for HPV1, HPV2 and HPV7 by a polymerase chain reaction method. The prevalence of hand warts was 33.3% in the abattoir workers, 34.1% in the butchers, 19.5% in the engineers and 14.7% in the office workers. Scrapings were taken from 247 of 267 subjects with warts, and HPV DNA was detected in 151 samples. The most common viruses were HPV2 (94 men) and HPV7 (76 men). The excess of warts in meat workers was largely due to HPV7, which was found in only two of the office workers, and was not found in any of the engineers. Logistic regression analysis showed no association between the prevalence of hand warts (or HPV2 and HPV7 specifically) and hand trauma, cold and wet working conditions, smoking, atopy, or handling any particular kind of meat. We suggest that some constituent of animal flesh predisposes to replication of HPV7 in keratinized epithelium.

Southern blot analysis of skin biopsies for human papillomavirus DNA: renal allograft recipients in south-eastern Queensland

The 104 skin biopsies from 34 patients who attended a Renal Transplant Unit in Brisbane over 12 months included 40 squamous cell carcinoma (SCC), 22 solar keratoses, 4 hyperkeratoses, 18 warts and 11 basal cell carcinoma (BCC). Human papillomavirus (HPV) DNA was identified by Southern blot hybridisation using, as individual probes, purified insert DNA from recombinant HPV 1, 2, 3 or 3/10, 4, 5 or 5/8, 7, 11, 16, 18 and 41 under relaxed conditions and characterised by restriction enzyme analysis and Southern blot hybridisation under more stringent conditions. Genomic HPV DNA was characterised in 7 skin biopsies from 4 renal allograft recipients (RARs): HPV 1A in a SCC (20 copies/cell) and a BCC (10 copies/cell) from the one patient, HPV 36 (20 copies/cell) in a SCC, HPV 1A [symbol: see text] 1000 copies/cell) in a wart and HPV 2B (200-800 copies/cell) in 3 warts from the one patient. Only HPV 1A in the SCC exhibited a significant degree of subtype variation. HPV DNA was identified in another 5 skin biopsies from another 4 RARs: HPV 3A in a wart and a hyperkeratosis, HPV 3/10-related DNA in 2 solar keratoses and HPV 5/8-related DNA in another (20-50 copies/cell). The incidence of HPV 5 (or 5-related HPVs) in RAR SCC was very low and that of HPV DNA in RAR warts was lower than that recorded elsewhere but this was not due to insensitivity of the assays. There was no evidence for a role for HPV in the aetiology of skin cancer in RARs in south-eastern Queensland but the possibility remains that as yet unidentified HPV types are involved.

Identification and characterization of novel promoters in the genome of human papillomavirus type 18

Most studies on the regulation of gene expression in human papillomaviruses (HPV) have focused on the promoter for the early genes E6 and E7. This promoter is located at the junction between the long control region and the E6 open reading frame. RNA mapping studies have suggested that additional promoters may exist in other parts of the genome. In this study, we used a combination of transcription in vitro and an analysis of RNA produced in vivo in transfected cells to identify three novel promoters in the genome of human papillomavirus type 18. These promoters are located in front of the E2 gene (P2598), within the E2 coding sequences (P3036), and at the end of the L2 open reading frame (P5600). They were active in HeLa cells, as shown by a chloramphenicol acetyltransferase assay. The activity of the P3036 promoter was stimulated by the bovine papillomavirus type 1 E2 protein.

Serological responses to human papillomavirus type 16 antigens in women before and after renal transplantation

Female renal transplant recipients have an increased incidence of human papillomavirus (HPV) associated lesions, such as cervical dysplasia and neoplasia [Schneider et al., 1983]. In this study we tested the serological responses by enzyme-linked immunoadsorbent assays (ELISA) to 3 different antigenic regions of HPV type 16. Sera from 35 female renal transplant patients collected before and at different times, up to 3 years, after transplantation were collected and tested. Before transplantation IgG antibodies against peptide 49, corresponding to the HPV L2 region, were found in 21/35 of the patients' sera. Of the L2 positive sera, 16 also demonstrated activity with the HPV L1 region derived peptide 31. All sera that were active against peptide 31 (L1) were also reactive with peptide 49 (L2). After renal transplantation, the antibody levels against these 2 peptides (peptides 49 and 31) dropped significantly (OD > or = 0.2) in all previously positive sera and remained so throughout the study, which lasted up to 3 years. The proportion of patients with IgA activity against the E2 region (peptide 245), which is common among patients with cervical neoplasia, increased from 9/35 before transplantation to 18/35 after transplantation. In parallel, we monitored 25 of these patients' sera before and after transplantation for antibody activity against measles, adenoviruses, and cytomegaloviruses (CMV). The majority of these sera--17/25 (68%) and 18/25 (72%), respectively--had no titer changes against measles and adenoviruses. Furthermore, the changes in antibody titers observed with CMV in these patients were not correlated with the fate of the antibodies against the HPV peptides.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevalence of HPV in a Melbourne female STD population: comparison of RNA and DNA probes in detecting HPV by dot blot hybridization

A total of 377 women, consecutively selected as first attenders to a sexually transmitted diseases clinic in Melbourne, Australia, were examined for overt Condylomata acuminata and were screened for genital HPV DNA types 6, 11, 16, 18, 31, 33 and (35) using 2 dot blot hybridization methods. Overall, there was a 90% positivity correlation between the 2 methods with HPV DNA being detected in 12% of ectocervical samples. Overt warts were found in 15% of the women and HPV DNA was detected at the cervix in 35% with cytology predicting HPV with or without dysplasia in 27%. Thirteen percent had a past history of warts but none on examination and HPV DNA was evident in 16% while 18% had cytological features of HPV. Those with no warts evident and no past history of warts had both HPV DNA and cytological features of HPV in 7%.

Use of antibodies against a synthetic peptide of the E6 protein of human papillomavirus (HPV) type 16 for the diagnosis of genital HPV lesions

The E6 open reading frame of the human papillomavirus (HPV) 16 codes for a protein of 158 amino acids with a theoretical molecular weight of 19.1 kD. A peptide corresponding to 147-158 amino acids (NH2-RSSRTRRETQLC-COOH) was synthesized, coupled to haemocyanin and used for immunization of rabbits. The antibodies obtained were used for the immunohistochemical analysis of a series of 41 paraffin-embedded biopsies including 29 cases of HPV 16-associated cervical lesions, five HPV 6, four HPV 11, and three HPV 18-associated genital warts. Expression of a reacting molecule (both intranuclear and cytoplasmic) could be demonstrated in 28/29 (96.6%) of the HPV 16 lesions, in 2/5 (40%) of the HPV 6, in 2/4 (50%) of the HPV 11, and in 3/3 of HPV 18 lesions. The intensity of the staining was weak in the HPV 6 and HPV 11 lesions, whereas it was classified as intense in 21/29 (72%) of the E6-positive HPV 16 lesions. Negative staining was almost invariably (5/6, 83%) confined to HPV-non-cervical intraepithelial neoplasia (HPV-NCIN) lesions, only 5/18 (27%) of which showed an intense staining. In contrast, intense staining was associated with CIN; 11/12 (92%) in HPV-CIN I and 8/11 (73%) in HPV-CIN II lesions. In the HPV 16 group, intense reactivity was more frequent in lesions shown to make clinical progression (8/9, 89%) as compared with those which underwent spontaneous regression (10/15, 66.7%). Topography of the immunostaining paralleled the localization of HPV DNA hybridization signals in 20/21 (95%) evaluable HPV 16 cases, in contrast to only 1/3 in HPV 18 cases and in none of the HPV 6 and HPV 11 lesions. These differences between HPV 16 and HPV 6/11 lesions in the staining with the HPV 16 E6 protein antibody might help explain at least some of the differences in their known biological behaviour.

Lymphoproliferative responses to human papillomaviruses in patients with cutaneous warts

In vitro lymphoproliferative responses of peripheral blood mononuclear cells (PBMC) from patients with cutaneous warts, caused by infection with human papillomavirus type 1 (HPV-1) or type 2 (HPV-2), were assayed during the course of treatment. Purified HPV-1 and HPV-2 were used as antigens, as well as herpes simplex virus (HSV) and concanavalin A (Con A). All patients had normal percentages of subsets within the PBMC population and normal lymphoproliferative responses to Con A, and those with a clinical history of HSV infections had positive lymphoproliferative responses to HSV. Responses to both HPV antigens were poor. Only 10 of 100 assays of PBMC from 26 patients showed a stimulation index greater than 2. Addition of interleukin 2 made little difference in most cases. No correlation of clinical status of warts, i.e. improving, unchanged or resolved, with lymphoproliferation was found. When the PBMC were depleted of plastic-adherent cells and enriched for T cells, some samples which had not shown a lymphoproliferative response to HPV-1 or HPV-2 became positive; this response was abolished when the adherent cells were re-added. Thus it is possible that the adherent cell population from a proportion of patients contains cells which suppress lymphoproliferation, or that an immunoregulatory network is present so that lymphoproliferation does not take place in vitro without prior activation and cloning of T cells.