Molecular cloning of a novel human papillomavirus (type 60) from a plantar cyst with characteristic pathological changes

HPV Infections-Classification, Pathogenesis, and Potential New Therapies

To date, more than 400 types of human papillomavirus (HPV) have been identified. Despite the creation of effective prophylactic vaccines against the most common genital HPVs, the viruses remain among the most prevalent pathogens found in humans. According to WHO data, they are the cause of 5% of all cancers. Even more frequent are persistent and recurrent benign lesions such as genital and common warts. HPVs are resistant to many disinfectants and relatively unsusceptible to external conditions. There is still no drug available to inhibit viral replication, and treatment is based on removing lesions or stimulating the host immune system. This paper presents the systematics of HPV and the differences in HPV structure between different genetic types, lineages, and sublineages, based on the literature and GenBank data. We also present the pathogenesis of diseases caused by HPV, with a special focus on the role played by E6, E7, and other viral proteins in the development of benign and cancerous lesions. We discuss further prospects for the treatment of HPV infections, including, among others, substances that block the entry of HPV into cells, inhibitors of viral early proteins, and some substances of plant origin that inhibit viral replication, as well as new possibilities for therapeutic vaccines.

Association of papillomavirus E6 proteins with either MAML1 or E6AP clusters E6 proteins by structure, function, and evolutionary relatedness

Papillomavirus E6 proteins bind to LXXLL peptide motifs displayed on targeted cellular proteins. Alpha genus HPV E6 proteins associate with the cellular ubiquitin ligase E6AP (UBE3A), by binding to an LXXLL peptide (ELTLQELLGEE) displayed by E6AP, thereby stimulating E6AP ubiquitin ligase activity. Beta, Gamma, and Delta genera E6 proteins bind a similar LXXLL peptide (WMSDLDDLLGS) on the cellular transcriptional co-activator MAML1 and thereby repress Notch signaling. We expressed 45 different animal and human E6 proteins from diverse papillomavirus genera to ascertain the overall preference of E6 proteins for E6AP or MAML1. E6 proteins from all HPV genera except Alpha preferentially interacted with MAML1 over E6AP. Among animal papillomaviruses, E6 proteins from certain ungulate (SsPV1 from pigs) and cetacean (porpoises and dolphins) hosts functionally resembled Alpha genus HPV by binding and targeting the degradation of E6AP. Beta genus HPV E6 proteins functionally clustered with Delta, Pi, Tau, Gamma, Chi, Mu, Lambda, Iota, Dyokappa, Rho, and Dyolambda E6 proteins to bind and repress MAML1. None of the tested E6 proteins physically and functionally interacted with both MAML1 and E6AP, indicating an evolutionary split. Further, interaction of an E6 protein was insufficient to activate degradation of E6AP, indicating that E6 proteins that target E6AP co-evolved to separately acquire both binding and triggering of ubiquitin ligase activation. E6 proteins with similar biological function clustered together in phylogenetic trees and shared structural features. This suggests that the divergence of E6 proteins from either MAML1 or E6AP binding preference is a major event in papillomavirus evolution.

Characterization of two novel gammapapillomaviruses, HPV179 and HPV184, isolated from common warts of a renal-transplant recipient

Gammapapillomavirus (Gamma-PV) is a diverse and rapidly expanding PV-genus, currently consisting of 76 fully characterized human papillomavirus (HPV) types. In this study, DNA genomes of two novel HPV types, HPV179 and HPV184, obtained from two distinct facial verrucae vulgares specimens of a 64 year-old renal-transplant recipient, were fully cloned, sequenced and characterized. HPV179 and HPV184 genomes comprise 7,228-bp and 7,324-bp, respectively, and contain four early (E1, E2, E6 and E7) and two late genes (L1 and L2); the non-coding region is typically positioned between L1 and E6 genes. Phylogenetic analysis of the L1 nucleotide sequence placed both novel types within the Gamma-PV genus: HPV179 was classified as a novel member of species Gamma-15, additionally containing HPV135 and HPV146, while HPV184 was classified as a single member of a novel species Gamma-25. HPV179 and HPV184 type-specific quantitative real-time PCRs were further developed and used in combination with human beta-globin gene quantitative real-time PCR to determine the prevalence and viral load of the novel types in the patient's facial warts and several follow-up skin specimens, and in a representative collection, a total of 569 samples, of HPV-associated benign and malignant neoplasms, hair follicles and anal and oral mucosa specimens obtained from immunocompetent individuals. HPV179 and HPV184 viral loads in patients' facial warts were estimated to be 2,463 and 3,200 genome copies per single cell, respectively, suggesting their active role in the development of common warts in organ-transplant recipients. In addition, in this particular patient, both novel types had established a persistent infection of the skin for more than four years. Among immunocompetent individuals, HPV179 was further detected in low-copy numbers in a few skin specimens, indicating its cutaneous tissue tropism, while HPV184 was further detected in low-copy numbers in one mucosal and a few skin specimens, suggesting its dual tissue tropism.

HPV-associated diseases

Nearly 200 distinct human papilloma viruses (HPVs) have now been recognized, and each is associated with a specific set of clinical lesions. They are associated with a spectrum of diseases, from benign verrucae vulgares and condylomata acuminata to the malignancies of the cervix, vulva, anus, and penis. Disease associated with HPV can be divided into skin and mucosal lesion of the genital and extragenital regions. The relationship between HPV and nonmelanoma skin cancer (NMSC) is important clinically, because NMSC is the most common form of malignancy among fair-skinned populations. HPVs have also been detected in skin tags, lichen sclerosus, seborrheic keratoses, actinic keratoses, epidermal cysts, psoriatic plaques, and plucked hairs, but cutaneous HPV can be found on healthy skin.

Characterization of human papillomavirus type 154 and tissue tropism of gammapapillomaviruses

The novel human papillomavirus type 154 (HPV154) was characterized from a wart on the crena ani of a three-year-old boy. It was previously designated as the putative HPV type FADI3 by sequencing of a subgenomic FAP amplicon. We obtained the complete genome by combined methods including rolling circle amplification (RCA), genome walking through an adapted method for detection of integrated papillomavirus sequences by ligation-mediated PCR (DIPS-PCR), long-range PCR, and finally by cloning of four overlapping amplicons. Phylogenetically, the HPV154 genome clustered together with members of the proposed species Gammapapillomavirus 11, and demonstrated the highest identity in L1 to HPV136 (68.6%). The HPV154 was detected in 3% (2/62) of forehead skin swabs from healthy children. In addition, the different detection sites of 62 gammapapillomaviruses were summarized in order to analyze their tissue tropism. Several of these HPV types have been detected from multiple sources such as skin, oral, nasal, and genital sites, suggesting that the gammapapillomaviruses are generalists with a broader tissue tropism than previously appreciated. The study expands current knowledge concerning genetic diversity and tropism among HPV types in the rapidly growing gammapapillomavirus genus.

Identification of a novel human gammapapillomavirus species

By using random PCR amplification, shotgun sequencing and sequence similarity searches, we analysed nucleic acids present in cell cultures inoculated with samples from unexplained cases of encephalitis. We identified a divergent human papillomavirus (HPV) sequence originating from a rectal swab. The full genome was amplified by inverse PCR and sequenced. The prototype of the sixth gammapapillomavirus species, HPV116, was not found in the patient's cerebrospinal fluid or respiratory secretions, nor in culture supernatants from other unexplained cases of encephalitis, indicating that its identification in an encephalitis patient was accidental.

[HPV-associated cutaneous lesions]

More than 100 HPV genotypes are presently distinguished by comparing the DNA sequence of the L1 ORF of each HPV. Two important aspects of the nature of this group of heterogeneous viruses are the way in which specific HPV genotypes are associated with distinct clinical and histological morphologies and the way specific HPV genotypes affect distinct anatomical sites. The former is best evidenced by the HPV type specific cytopathic or cytopathogenic effect (CPE), whereas the latter is suggested by the marked preference of each HPV genotype for specific tissues and sites. Recent studies have also suggested that specific HPV genotypes may target epithelial stem cells at specific anatomical sites. HPV type-specific CPE is the central schema when we analyze and understand the HPV-associated diseases. The concept was suggested by the characterization of distinct HPVs from different types of warts: HPV 2/27/57 from common warts, HPV 3/10/28 from flat warts, HPV 6/11 from condyloma acuminatum, and HPV 5/8 from lesions of epidermodysplasia verruciformis (EV). In this paper, I summarize recent advances in HPV study field, especially on HPV-associated cutaneous lesions. These include inclusion warts, HPV-associated epidermoid cysts, HPV type specific activation of melanogenesis, a double infection with HPV 1 and HPV 63 within a single cell, primary target cells and life cycle of the virus, and the identification of novel genes that are associated EV. The HPV-associated cutaneous lesions thus pose important problems to be resolved in virology and human pathology.

Human papillomavirus infection and ultraviolet light exposure as epidermoid inclusion cyst risk factors in a patient with epidermodysplasia verruciformis?

Epidermoid inclusion cysts are common lesions with unclear etiology. We sought to examine evidence for human papillomavirus (HPV) infection and ultraviolet light (UV) exposure as risk factors in the formation of epidermoid inclusion cysts. We performed HPV typing of biopsied cysts with polymerase chain reaction for a patient with darkly-pigmented skin, epidermodysplasia verruciformis (EV) and more than 250 photodistributed cysts. HPV types 8 and 6 DNA was demonstrated within biopsy specimens of 3 cysts. In one biopsy specimen, abnormal keratinocytes bridging the follicular infundibulum were seen. We concluded that UV exposure and HPV viral infection may be risk factors for the formation of epidermoid inclusion cysts.

Association of human papillomavirus infection with palmoplantar epidermal cysts in Korean patients

Human papillomavirus (HPV) infection can develop into many different kinds of diseases ranging from simple warts to carcinoma in situ. Some investigators have recently suggested that HPV infection could be closely related to palmoplantar epidermal cysts. The aim of this study was to determine the existence of HPV and its subtype in palmoplantar epidermal cysts of Korean patients. We investigated 13 cases of palmoplantar epidermal cysts by employing clinical, histopathological and immunohistochemical examinations. In addition, PCR was performed using HPV 57 and 60 type primers. Four of the 13 cases (30.8%) showed the distinct histopathological features of palmoplantar epidermal cysts such as parakeratosis, vacuolar structures and eosinophilic inclusion bodies and these 4 cases showed positive immunohistochemical staining reactions for HPV. PCR for HPV detected type 60-positive bands in 5 of the 13 cases (38.5%), which included the 4 cases that were positive for immunohistochemical staining. These results show that HPV is associated with some cases of palmoplantar epidermal cysts in Korean patients, suggesting that HPV may play a role in the pathogenesis of these cysts.

Human papillomavirus-associated plantar epidermoid cyst related to epidermoid metaplasia of the eccrine duct epithelium: a combined histological, immunohistochemical, DNA-DNA in situ hybridization and three-dimensional reconstruction analysis

BACKGROUND

We recently proposed that certain palmoplantar epidermoid cysts may be related to eccrine ducts and that human papillomavirus (HPV) 60 may play a role in their pathomechanism. However, the origin of palmoplantar epidermoid cysts is still controversial.

OBJECTIVES

To examine the contribution of eccrine ducts and HPV 60 in the development of epidermoid cysts.

METHODS

Five epidermoid cysts and four ridged warts that had developed on the soles of a patient were studied histologically, immunohistochemically and by DNA-DNA in situ hybridization. Using serial sections obtained from its entire body, a three-dimensional reconstruction (3DR) analysis was performed on the smallest cyst to analyse the relationship between the epidermoid cyst, eccrine duct and the overlying epidermis.

RESULTS

Histological and DNA-DNA in situ hybridization analyses demonstrated both homogeneous intracytoplasmic inclusion bodies pathognomonic for HPV 60 infection and HPV 60 DNA sequences not only in all of the epidermoid cysts and ridged warts but also in the acrosyringeal portion of an eccrine duct, with the dermal portion of which the smallest cyst had been revealed to connect by 3DR analysis. However, immunohistochemical analyses using antibodies against human carcinoembryonic antigen (CEA), involucrin and several cytokeratins (CKs) revealed that the immunoreactivity of the cyst was not identical to that of the eccrine dermal duct but was identical to that of suprabasal layers of the epidermis.

CONCLUSIONS

It was clearly demonstrated that an HPV 60-associated epidermoid cyst with immunoreactivities for CEA, involucrin and CKs which were identical to those of the epidermis connected with the eccrine dermal duct, supporting the idea that certain palmoplantar epidermoid cysts may develop following the epidermoid metaplasia of eccrine ducts with HPV 60 infection.

Detection of human papillomavirus type 57 in the tissue of a plantar epidermoid cyst

Plantar epidermoid cysts with human papillomavirus (HPV) infection are not rare in Japan. Most of them show the cytopathic effect of HPV type 60 - homogeneous intracytoplasmic inclusion bodies. Our case presented a plantar epidermoid cyst with vacuolation around the granular cell layer without any features of HPV type 60. In situ hybridization and polymerase chain reaction followed by DNA sequencing analysis revealed an association with HPV type 57.

VGJ phi, a novel filamentous phage of Vibrio cholerae, integrates into the same chromosomal site as CTX phi

We describe a novel filamentous phage, designated VGJ phi, isolated from strain SG25-1 of Vibrio cholerae O139, which infects all O1 (classical and El Tor) and O139 strains tested. The sequence of the 7,542 nucleotides of the phage genome reveals that VGJ phi has a distinctive region of 775 nucleotides and a conserved region with an overall genomic organization similar to that of previously characterized filamentous phages, such as CTX phi of V. cholerae and Ff phages of Escherichia coli. The conserved region carries 10 open reading frames (ORFs) coding for products homologous to previously reported peptides of other filamentous phages, and the distinctive region carries one ORF whose product is not homologous to any known peptide. VGJ phi, like other filamentous phages, uses a type IV pilus to infect V. cholerae; in this case, the pilus is the mannose-sensitive hemagglutinin. VGJ phi-infected V. cholerae overexpresses the product of one ORF of the phage (ORF112), which is similar to single-stranded DNA binding proteins of other filamentous phages. Once inside a cell, VGJ phi is able to integrate its genome into the same chromosomal attB site as CTX phi, entering into a lysogenic state. Additionally, we found an attP structure in VGJ phi, which is also conserved in several lysogenic filamentous phages from different bacterial hosts. Finally, since different filamentous phages seem to integrate into the bacterial dif locus by a general mechanism, we propose a model in which repeated integration events with different phages might have contributed to the evolution of the CTX chromosomal region in V. cholerae El Tor.

Recurrent 'sterile' verrucous cyst abscesses and epidermodysplasia verruciformis-like eruption associated with idiopathic CD4 lymphopenia

Rupture of follicular (epidermoid) cysts is believed to be the consequence of bacterial infection. We report a 24-year-old man with idiopathic CD4 lymphopenia and chronic Mycobacterium avium intracellulare infection who developed multiple, recurring painful abscesses over the distal extremities that increased in number and severity when systemic steroid and interferon-gamma treatment was instituted for interstitial lung disease. Cultures were consistently negative for microorganisms, but pathological examination revealed ruptured epidermoid cyst walls with human papillomavirus (HPV) viropathic changes (keratinocytes with perinuclear halos and abundant basophilic keratohyaline granules). Cutaneous examination showed numerous, widespread flat-topped papules and achromic macules over the extremities, head and neck. Nested polymerase chain reaction analysis for HPV DNA revealed that the abscess-related cyst walls harboured epidermodysplasia verruciformis (EV)-associated HPV types 20, 24, alb-7 (AY013872) and 80. His cutaneous lesions harboured HPV types 3, 8 and 80. Similar to past reports, our patient developed an EV-like eruption in the setting of immunodeficiency. In this instance, EV-associated HPV infection of the follicular infundibular epithelium or pre-existing cysts in the setting of immunodeficiency may have led to cystic growth, rupture and subsequent painful inflammation.

Detection of human papillomavirus 60 in epidermal cysts of nonpalmoplantar location

Human papillomavirus (HPV) types 57 and 60 are associated with epidermal cysts of palmoplantar location (PPECs). Recently, there was a report of HPV 60 in a wart located in a nonpalmoplantar area as a possible precursor of a nonpalmoplantar epidermal cyst (NPPEC). There has been no study that has examined the presence and frequency of HPV in ordinary NPPECs. We reviewed 63 cases of epidermal cysts, including 59 NPPECs and 4 PPECs. After routine histopathologic review, polymerase chain reaction (PCR) of extracted DNA, sequencing of PCR products, and, finally, a homology search were undertaken. As a result, 9 of 63 (14.3%) cysts, including 6 of 59 NPPECs (10.2%), showed a positive reaction on PCR. By homology search after PCR, all were demonstrated as HPV 60. For NPPECs, no variables, including some histopathologic features, are significantly related to the presence of HPV 60 in univariate or multivariate analysis (P > 0.05).

Multiple palmar epidermoid cysts

Implantation of epidermal fragments into the dermis has been pointed out as the cause of common epidermal cysts. However, some palmoplantar epidermoid cysts have been reported to be caused by human papillomavirus (HPV) infection or to be derived from eccrine ducts. A 65-year-old left-handed woman presented with extraordinary multiple epidermoid cysts on the palm and volar aspect of the fingers of her left hand. HPV infection was not detected by immunohistochemistry, in situ hybridization and polymerase chain reaction. Histological investigation revealed syringeal structures within the cyst wall and in the cyst cavity. Carcinoembryonic antigen was observed in these syringeal structures but was not specifically stained in the cyst wall cells by immunohistochemistry. The cytokeratin composition of the cyst wall cells was similar to that of the nonadnexal epidermis.

Syringocystadenoma papilliferum contiguous to a verrucous cyst

BACKGROUND

Syringocystadenoma papilliferum (SCAP) and verrucous cyst are two uncommon benign tumors. The simultaneous occurrence of the two lesions has not been reported before.

METHODS

We report four cases of the simultaneous occurrence of the two rare lesions as so-called collision lesions with a review of the literature.

CONCLUSION

The relationship of SCAP with viral infection needs further investigation.

Topical 5% imiquimod long-term treatment of cutaneous warts resistant to standard therapy modalities

BACKGROUND

Long-lasting cutaneous warts may represent an unbearable stigma to patients and therefore pose a singular challenge for the physician. Generally, these warts are induced by human papillomavirus (HPV) 2, HPV-27 or HPV-57.

OBJECTIVES

The present study was conducted to evaluate the efficacy and safety of long-term treatment with imiquimod 5% cream applied to long-lasting (mean duration 6.3 years) common warts, which had been resistant to previous therapeutic interventions.

PATIENTS AND METHODS

Imiquimod cream was self-applied by the patients twice daily. Assessment of response and occurrence of side-effects was performed every 4 weeks until clinical cure or up to a maximum of 24 weeks. A total of 37 patients were recruited.

RESULTS

31 out of 37 patients completed the treatment. 10 out of 37 patients experienced a total clearance of their warts (27%). The mean duration to clearance was 19.2 weeks. 18 patients (49%) showed a reduction of more than 50% and 5 patients (14%) a reduction of less than 50%.

CONCLUSION

Our data demonstrate that the long-term topical application of imiquimod 5% cream is an effective treatment for otherwise therapy-resistant cutaneous warts without causing any meaningful side-effects.

Protean manifestations of human papillomavirus type 60 infection on the extremities

BACKGROUND

Human papillomavirus type 60 (HPV-60) induces a ridged wart or an epidermal cyst on the sole of the foot, exhibiting identical pathological changes, with a single refractile eosinophilic intracytoplasmic inclusion body in infected cells. However, there is no information on the role of HPV-60 in the development of cutaneous lesions on other anatomical sites.

OBJECTIVES

To perform the clinicopathological analysis of various cutaneous lesions of a patient in relation to HPV genotype.

PATIENT

A 50-year-old male patient developed multiple papules, plaques and nodules on his hand, arm and legs.

RESULTS

Clinicopathologically, the lesions were classified into three categories. A common wart on the finger showed papillomatosis and acanthosis characterized by numerous keratohyalin granules. Plane warts on the arm showed perinuclear vacuolization of the cells in the upper Malpighian layer. On the other hand, a pigmented papillomatous nodule on the finger, and the other lesions on the hands and legs exhibited similar histological features with a unique cytoplasmic eosinophilic inclusion body. All the three categorized lesions were equally positive for HPV capsid antigen by immunohistochemistry. By blot hybridization analysis for HPV sequences, it was revealed that a common wart on the finger and plane warts on the arm harboured HPV-27 and HPV-3, respectively, while all the other lesions harboured HPV-60. The histological localization of each viral DNA was confirmed in the corresponding lesions by in situ hybridization.

CONCLUSIONS

HPV-60 is able to induce papular and nodular lesions on the extremities.

A case of a human-papillomavirus-60-induced wart with clinical appearance of both pigmented and ridged warts

Human papillomavirus (HPV) type 60 infection is histologically associated with characteristic homogeneous intracytoplasmic inclusion bodies. However, it remains unclear whether the virus is associated with cystic, pigmented or ridged plantar warts. We report a 51-year-old Japanese female with a HPV-60-induced plantar wart which showed the clinical appearance of both pigmented and ridged warts. Masson-Fontana staining revealed increased melanin granules in the epidermis of the wart. This observation suggests that HPV-60 may be associated not only with cystic warts but also with the specific morphology of ridged warts, and the biological disorder of hyperpigmentation may be controlled by additional unknown factors which differ from case to case.

A case of viral warts with particular fibrillar intracytoplasmic inclusion bodies

A new type of skin wart was observed in a Japanese patient. It was characterized by intracytoplasmic inclusions with a 'fibrillar' structure which were distinct from previously described wart-associated inclusions. The papillomavirus (HPV)-group-specific antigen could be detected, but DNA hybridization and PCR amplification using probes or PCR primers specific for the main skin HPV genotypes (including HPV-63 which is also associated with 'filamentous' inclusions) were negative. We consider that this cytopathic effect could correspond to an HPV genotype which has not yet been characterized.

Lifelong severe verrucosis associated with human papillomavirus type 2: report of a case with a 38-year follow-up

We describe a 67-year-old woman with disseminated warts which she had had for more than 38 years. The lesions consisted of common and plane warts, wart-like plaques and red-brownish macules similar to those in pityriasis versicolor. Furthermore, during follow-up, several solar keratoses, plaques of Bowen's disease and invasive squamous cell carcinomas were excised. The patient also had T-cell immunodeficiency of unknown aetiology. Histopathology demonstrated that all the warts showed the cytopathological features of common warts, but not those of the warts in epidermodysplasia verruciformis (EV). We investigated the presence of human papillomavirus (HPV) DNA in the warts by blot hybridization and molecular cloning and found that the lesions harboured HPV 2, but not EV-HPVs or other HPVs. In addition, the histopathological distribution of the viral DNA was confirmed in paraffin sections of warts from the patient at different ages by in situ hybridization. However, these investigations yielded negative results in specimens of Bowen's disease and invasive squamous cell carcinoma. These results demonstrated that the patient had been infected with HPV 2 from childhood, but the negative results for detection of DNA of HPV 2 in carcinomas from the patient do not support an oncogenic potential for HPV 2. In conclusion, HPV 2, an aetiological agent of common warts in the general population, may induce a lifelong severe verrucosis in some immunosuppressed patients.

Human papillomavirus 57 identified in a plantar epidermoid cyst

We report a 23-year-old Japanese man who had plantar warts on the right sole, beneath one of which an epidermoid cyst developed. On microscopic examination, an acanthotic epidermis markedly invaginated into the underlying dermis, resulting in an open epidermoid cyst. Not only the polymerase chain reaction but also an in situ hybridization detected HPV 57 DNA in the cyst. HPV 60 is the only type of HPV that has been identified in epidermoid cysts. To our knowledge, this is the first case report of an epidermoid cyst, in which a different type of virus from HPV 60 was identified. Histological features of the cyst were also different those of HPV 60-associated epidermoid cysts.

Detection of human papillomaviruses and eccrine ducts in palmoplantar epidermoid cysts

Although epidermoid cysts of the palms and soles have long been assumed to develop following implantation of an epidermal fragment as a result of a penetrating injury, the pathogenic mechanism is still controversial, and the discovery of a more common aetiological agent is awaited. Clinical, histological, immunohistochemical and molecular biological studies were performed on 119 epidermoid cysts of palmoplantar location, in order to examine the role of the eccrine ducts, and human papillomavirus (HPV), in the pathogenesis of this disorder. Characteristic histological features were found, including intracytoplasmic eosinophilic bodies (ICB: in 14 cases, 12%) in the cyst wall, vacuolar structures (V: in 28 cases, 24%), or parakeratotic nuclei (P: in 85 cases, 71%) within the keratinous mass in the cyst cavity. Ductal structures suggesting eccrine ducts (E: in 63 cases, 53%) were also found in the cyst wall or in the cyst cavity. Either ductal structures or carcinoembryonic antigen expression (66 cases, 55%) were noted in a total of 73 cases (61%). Papillomavirus common antigens were detected in 36 cases (30%) showing one or more of the three distinct histological features, i.e. ICB, V and P. Subsequently, hybridization experiments to detect HPV DNA were performed in 47 cases, revealing an association between cysts showing ICB or V and the presence of HPV 60 DNA sequences. On the basis of our results, we propose that epidermoid cysts in the palmoplantar regions may develop from eccrine ducts, and that HPV and injury may play a role in their pathogenesis.

Human-papillomavirus DNA in cholesteatomas

Cholesteatoma of the middle ear is a relatively common disorder, often with severe consequences. Histologically, the aggressively growing, bone-destructing form shows papillary growth and koilocytosis, which are characteristic of papillomavirus-induced lesions. A PCR (polymerase chain reaction) method using degenerate primers for the detection of any known or as yet unknown HPV (human papillomavirus) type was applied in screening 51 biopsies from 42 patients. A resulting 36% (16/45) of the cholesteatomas were found to contain papillomavirus DNA, which hybridized under stringent conditions with an HPV-II DNA probe. In 3 cases the presence of HPV-II DNA could be confirmed by sequencing the PCR products. The mere presence of this HPV DNA does not prove an etiological role of this group of viruses in the induction of cholesteatomas. It does, however, identify another group of human proliferative lesions putatively linked to papillomavirus infections.

Detection of human papillomavirus type 60 in plantar cysts and verruca plantaris by the in situ hybridization method using digoxigenin labeled probes

BACKGROUND

Since 1987, many cases have been reported in which human papillomavirus (HPV) could be associated with epidermoid cysts of the palms and soles. In 1989, the HPV found in an induced epidermoid cyst was cloned and named HPV 60.

OBJECTIVE

Our purpose was to examine the relationship of HPV 60 to plantar cysts.

METHODS

Ten cases of plantar cysts and two cases of verruca plantaris containing single inclusion bodies were obtained by biopsy and examined by the in situ hybridization (ISH) method with a digoxigenin labeled HPV 60 DNA probe.

RESULTS

Six of ten cases were found to have cytopathic effect (CPE) in the cyst wall and inner contents of the cyst. HPV 60 was detected in these cases by ISH. Two cases of verruca plantaris showing CPE also demonstrated the presence of HPV 60. Of the six HPV type 60 positive cases, four cases also showed CPE in the overlying epidermis.

CONCLUSION

At first, punctate keratotic lesions are induced by HPV 60. HPV 60 induces irregular elongation of the rete ridges into the dermis. Plantar cysts probably form as a result of the traumatic implantation of HPV 60 infected epidermis with irregularly long and narrow rete ridges into the dermis.

New types of human papillomaviruses and intracytoplasmic inclusion bodies: a classification of inclusion warts according to clinical features, histology and associated HPV types

Two new types of intracytoplasmic inclusion bodies (ICBs) associated with distinct clinical features, and the presence of DNA of distinct types of human papillomaviruses (HPVs) are reported. One hundred and seven cutaneous warts containing ICBs were grouped into three categories according to distinct clinicopathological features: 67 were wart lesions with well-known granular (Gr)-ICB, 13 were punctate keratotic lesions with filamentous (Fl)-ICB and 31 were pigmented warts with homogeneous (Hg)-ICB. Molecular biological studies were performed in order to assess a specific association of each group of warts with distinct types of HPV. HPV-1 DNA sequences were detected in all the lesions with a Gr-ICB. Punctate keratotic lesions with Fl-ICB were associated with HPV-63, which was newly cloned from such a lesion. One of the samples also contained HPV-1 DNA. Pigmented warts with Hg-ICBs contained one of the related HPVs, i.e. HPV-4, HPV-60 or a novel type of HPV, HPV-65. Based on these associations, a classification of inclusion warts is proposed.