The presence of antibodies against virus-like particles of epidermodysplasia verruciformis-associated humanpapillomavirus type 8 in patients with actinic keratoses

Advancements in elucidating the pathogenesis of actinic keratosis: present state and future prospects

Solar keratosis, also known as actinic keratosis (AK), is becoming increasingly prevalent. It is a benign tumor that develops in the epidermis. Individuals with AK typically exhibit irregular, red, scaly bumps or patches as a result of prolonged exposure to UV rays. These growths primarily appear on sun-exposed areas of the skin such as the face, scalp, and hands. Presently, dermatologists are actively studying AK due to its rising incidence rate in the United States. However, the underlying causes of AK remain poorly understood. Previous research has indicated that the onset of AK involves various mechanisms including UV ray-induced inflammation, oxidative stress, complex mutagenesis, resulting immunosuppression, inhibited apoptosis, dysregulated cell cycle, altered cell proliferation, tissue remodeling, and human papillomavirus (HPV) infection. AK can develop in three ways: spontaneous regression, persistence, or progression into invasive cutaneous squamous cell carcinoma (cSCC). Multiple risk factors and diverse signaling pathways collectively contribute to its complex pathogenesis. To mitigate the risk of cancerous changes associated with long-term UV radiation exposure, prompt identification, management, and prevention of AK are crucial. The objective of this review is to elucidate the primary mechanisms underlying AK malignancy and identify potential treatment targets for dermatologists in clinical settings.

Exposome and Skin. Part 2. The Influential Role of the Exposome, Beyond UVR, in Actinic Keratosis, Bowen's Disease and Squamous Cell Carcinoma: A Proposal

Actinic keratosis (AK) is the main risk factor for the development of cutaneous invasive squamous cell carcinoma (SCC). It represents the first sign of severe chronic ultraviolet radiation exposure, which has a clear significant effect. Nevertheless, the skin is exposed to many other exposome factors which should be thoroughly considered. Our aim was to assess the impact of exposome factors other than ultraviolet radiation (UVR) on the etiopathology of AK and Bowen's disease (BD) and progression of AK to SCC and to design tailored prevention strategies. We performed an exhaustive literature search in September 2021 through PubMed on the impact of exposome factors other than UVR on AK, BD and SCC. We conducted several parallel searches combining terms of the following topics: AK, BD, SCC and microbiome, hormones, nutrition, alcohol, tobacco, viral infections, chemical contaminants and air pollution. Notably, skin microbiome studies have shown how Staphylococcus aureus infections are associated with AK and AK-to-SCC progression by the production of chronic inflammation. Nutritional studies have demonstrated how a caloric restriction in fat intake, oral nicotinamide and moderate consumption of wine significantly reduce the number of premalignant keratoses and SCC. Regarding lifestyle factors, both alcohol and smoking are associated with the development of SCC in a dose-dependent manner. Relevant environmental factors are viral infections and chemical contaminants. Human papillomavirus infections induce deregulation of cellular proliferation and are associated with AK, BD and SCC. In addition to outdoor jobs, occupations such as industrial processing and farming also increase the risk of developing keratoses and SCC. The exposome of AK will undoubtedly help the understanding of its etiopathology and possible progression to SCC and will serve as a basis to design tailored prevention strategies.

Human Papillomavirus Vaccine Efficacy and Effectiveness against Cancer

Human papillomavirus (HPV) is the most common sexually transmitted infection, with 15 HPV types related to cervical, anal, oropharyngeal, penile, vulvar, and vaginal cancers. However, cervical cancer remains one of the most common cancers in women, especially in developing countries. Three HPV vaccines have been licensed: bivalent (Cervarix, GSK, Rixensart, Belgium), quadrivalent (Merck, Sharp & Dome (Merck & Co, Whitehouse Station, NJ, USA)), and nonavalent (Merck, Sharp & Dome (Merck & Co, Whitehouse Station, NJ, USA)). The current HPV vaccine recommendations apply to 9 years old and above through the age of 26 years and adults aged 27–45 years who might be at risk of new HPV infection and benefit from vaccination. The primary target population for HPV vaccination recommended by the WHO is girls aged 9–14 years, prior to their becoming sexually active, to undergo a two-dose schedule and girls ≥ 15 years of age, to undergo a three-dose schedule. Safety data for HPV vaccines have indicated that they are safe. The most common adverse side-effect was local symptoms. HPV vaccines are highly immunogenic. The efficacy and effectiveness of vaccines has been remarkably high among young women who were HPV seronegative before vaccination. Vaccine efficacy was lower among women regardless of HPV DNA when vaccinated and among adult women. Comparisons of the efficacy of bivalent, quadrivalent, and nonavalent vaccines against HPV 16/18 showed that they are similar. However, the nonavalent vaccine can provide additional protection against HPV 31/33/45/52/58. In a real-world setting, the notable decrease of HPV 6/11/16/18 among vaccinated women compared with unvaccinated women shows the vaccine to be highly effective. Moreover, the direct effect of the nonavalent vaccine with the cross-protection of bivalent and quadrivalent vaccines results in the reduction of HPV 6/11/16/18/31/33/45/52/58. HPV vaccination has been shown to provide herd protection as well. Two-dose HPV vaccine schedules showed no difference in seroconversion from three-dose schedules. However, the use of a single-dose HPV vaccination schedule remains controversial. For males, the quadrivalent HPV vaccine possibly reduces the incidence of external genital lesions and persistent infection with HPV 6/11/16/18. Evidence regarding the efficacy and risk of HPV vaccination and HIV infection remains limited. HPV vaccination has been shown to be highly effective against oral HPV type 16/18 infection, with a significant percentage of participants developing IgG antibodies in the oral fluid post vaccination. However, the vaccines’ effectiveness in reducing the incidence of and mortality rates from HPV-related head and neck cancers should be observed in the long term. In anal infections and anal intraepithelial neoplasia, the vaccines demonstrate high efficacy. While HPV vaccines are very effective, screening for related cancers, as per guidelines, is still recommended.

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.

Predictors of squamous cell carcinoma in high-risk patients in the VATTC trial

Invasive squamous cell carcinoma (SCC) of the skin is one of the most common cancers in the United States, with no proven means for prevention other than systemic retinoids, which have significant toxicity, and sunscreen. We sought to determine the risk factors for invasive SCC on the face or ears in a high-risk population comprising 1,131 veterans in the Veterans Affairs Topical Tretinoin Chemoprevention (VATTC) Trial. Participants were required to have been diagnosed with at least two keratinocyte carcinomas (KCs) in the 5 years prior to enrollment. The median duration of follow-up was 3.7 years. Twenty-three percent of the participants developed a new invasive SCC, and the cumulative risk of invasive SCC was 30% at 5 years. The following factors independently predicted for new invasive SCCs: number of invasive SCCs and number of in situ SCCs in the 5 years prior to enrollment, actinic keratoses count at enrollment, a history of ever use of topical 5-fluorouracil, and total occupational time spent outdoors. In contrast, the use of angiotensin-convering enzyme inhibitors or angiotensin receptor blockers during the study and a history of warts anywhere on the body were found to protect against new invasive SCCs. These independent predictors remained the same for all SCCs (invasive and in situ combined). The number of basal cell carcinomas in the 5 years prior to enrollment, sunburns, sun sensitivity, and recreational sun exposure were not associated with new SCCs. These findings identify key risk factors for additional SCCs in patients with multiple prior KCs, and suggest that a history of warts may be associated with reduced SCC risk.

Human papillomavirus load in eyebrow hair follicles and risk of cutaneous squamous cell carcinoma

BACKGROUND

Beta-human papillomavirus (betaPV) may play a role in the development of cutaneous squamous cell carcinoma (SCC). However betaPV is highly prevalent, and it may only be people with a higher viral load who have increased risk of SCCs. We therefore examined the association between betaPV load and SCCs.

METHODS

We recruited 448 immunocompetent cases with SCCs and 464 controls from Italy and Australia and 497 immunosuppressed organ transplant recipients (OTR; 179 cases and 318 controls) from Europe. We used reverse hybridization to genotype 25 betaPV types in eyebrow hair follicles and determined the viral load for eight selected types using quantitative PCR. We used logistic regression to assess associations between type-specific and cumulative viral load and SCCs.

RESULTS

Australian and OTR participants in the highest cumulative load tertile were at significantly higher risk of SCCs than those in the lowest tertile. Those with more than four betaPV types in the high load tertile were at approximately three-fold increased risk of SCCs. In Australia, HPV23 and 36 loads were significantly associated with SCCs, with borderline associations for HPV5 and 38. In OTR, HPV8 and 38 loads were significantly associated and HPV20 and 36 were borderline. We found little evidence for an association between load and SCCs in Italy.

CONCLUSIONS

High viral load may be associated with risk of cutaneous SCCs, with total load seemingly more important than the load of any specific type.

IMPACT

Our findings lend weight to the hypothesis that HPV plays a role in skin carcinogenesis.

Cutaneous squamous cell carcinoma and human papillomavirus: is there an association?

BACKGROUND

The role of human papillomavirus (HPV) in the induction and maintenance of cervical, anogenital, and some oropharyngeal carcinomas is well recognized, but its role in cutaneous squamous cell carcinoma (SCC) remains to be elucidated. HPV is thought to act as a possible cocarcinogen in the development of SCC.

OBJECTIVE

To review the literature assessing the correlation between and possible causation of HPV and cutaneous SCC in immunocompetent and immunocompromised populations.

METHODS

We reviewed HPV sampling and detection methods, epidemiologic studies examining HPV carriage in immunocompetent and immunosuppressed individuals, and evidence asserting an association between HPV and cutaneous SCC.

RESULTS

Although an abundant body of evidence points toward a link between HPV and cutaneous SCC, many studies indicate otherwise. Recent studies have focused on viral activity in addition to DNA presence.

CONCLUSION

The possibility exists that HPV may play a role in the induction but not maintenance of cutaneous SCC.

Review: antibodies to cutaneous human papillomaviruses

Human papillomaviruses (HPVs) are small double-stranded DNA viruses that infect the epithelia of skin or mucosa. Cutaneous HPV is ubiquitous and many children have skin warts at some stage during childhood and a high proportion of the adult population have asymptomatic skin HPV infections. While a subset of mucosal HPV types are involved in cervical cancer, the role for cutaneous HPV types in skin cancer is still under debate. There is some evidence that the skin HPV types have mechanisms to induce skin cancer, but the role of HPV infection has never been proved in larger epidemiological studies and is not well understood. Cutaneous HPV serology has been employed more commonly during the last decade to help find a link between cutaneous HPV and skin cancer. This review covers the findings from cutaneous HPV serology studies published during the last decade and discusses differences in seroprevalence and risk factors.

The Association between cutaneous squamous cell carcinoma and betapapillomavirus seropositivity: a cohort study

BACKGROUND

It is currently unclear whether betapapillomaviruses (betaPV) play a role in the etiology of cutaneous squamous cell carcinoma (SCC). We investigated the association between betaPV antibodies and subsequent SCC in a population-based cohort study.

METHODS

Serum samples were collected in 1992 and/or 1996 from 1,311 participants of the community-based Nambour Skin Cancer Study. These were tested for the presence of L1 antibodies against 21 different betaPV types. Histologically diagnosed SCCs were ascertained through three full-body skin examinations and linkage with the local pathology laboratories. We used age- and sex-adjusted Cox proportional hazards models to analyze the relationship between betaPV antibodies and SCC occurrence from 1992 until 2007.

RESULTS

SCC was newly diagnosed in 150 people. No associations were found between the presence of any betaPV L1 antibodies and the occurrence of SCC (HR = 1.0), and stratification by sex, skin color, and sunburn propensity did not affect these results. However, among people who were less than 50 years old in 1992, the presence of betaPV antibodies was associated with a two-fold increased risk of SCC. There was no significant association between antibodies to any individual betaPV type examined and the later development of SCC.

CONCLUSIONS

Whether betaPV infection of the skin, and indirectly betaPV antibodies, are involved in the oncogenic process in the general population remains unclear, and this longitudinal study provides only limited support.

IMPACT

This study emphasizes the need for additional longitudinal studies of HPV (human papilloma virus) and SCC, to avoid the possibility of reverse causality in case--control studies.

Enhanced StefinA and Sprr2 expression during papilloma formation in HPV8 transgenic mice

BACKGROUND

The human papillomavirus type 8 (HPV8) is associated with the development of non-melanoma skin cancer. Transgenic mice expressing the complete early gene region of HPV8 (E6/E7/E1/E2/E4=CER) or E6 separately under the control of the keratin14 promoter spontaneously developed papillomas characterized by varying degrees of epidermal dysplasia. Papilloma growth could be synchronized by a single UVA/B irradiation of the skin, which led to the development of papillomas within three weeks.

OBJECTIVE

The objective of this study was to identify alterations in cellular gene expression correlated with HPV8 oncogene expression in transgenic mice.

METHODS

We applied global gene expression profiling by microarray analysis and confirmed deregulation of cellular genes by qRT-PCR and immunohistochemical analysis.

RESULTS

By comparison of non-lesional HPV8-CER skin with skin of the parental mouse strain FVB/n, two cellular genes, namely StefinA and Sprr2, coding for precursor proteins of the cornified envelope, were predicted to be strongly upregulated in transgenic skin, which could be confirmed in subsequent qRT-PCR experiments. StefinA and Sprr2 mRNA expression was enhanced until day 7 after UV treatment with higher levels in HPV8 positive skin. While the expression of both genes returned to a normal level in the course of epidermis regeneration in wt mice, the expression persisted elevated in hyperplastic transgenic skin. Staining of an UV induced papilloma of FVB/n wt mouse revealed also strong expression of StefinA and Sprr2 indicating that upregulation in later stages of papilloma formation is independent of HPV8.

CONCLUSION

In non-lesional HPV8-CER transgenic skin StefinA and Sprr2 were found to be indirect/direct transcriptional targets of HPV8.

Prevalence and stability of antibodies to 37 human papillomavirus types--a population-based longitudinal study

Information about serostability of cutaneous HPV types over time is very limited. We investigated seroprevalence and serostability of 37 different HPV types over 4½ years in an Australian population-based study. Sera and data were analyzed for 390 people who had never been diagnosed with SCC and had blood collected in 1992, 1993 and 1996. Eighty-six percent of participants were seropositive to at least one of the 37 HPV types at baseline. HPV-4 was the type with the highest seroprevalence (41%), followed by HPV-38 and HPV-8 (both 33%). Over 90% of people retained their baseline serostatus during the 4½ year follow-up. Highest serostability was observed for HPV-88 (99.7% stayed seropositive or seronegative), while HPV-65 was least stable with 17% altering their serostatus during follow-up. Seroprevalence to cutaneous HPV types are relatively stable over time, and a single measure can be used as a reasonable marker of long-term antibody status.

Genus beta human papillomaviruses and incidence of basal cell and squamous cell carcinomas of skin: population based case-control study

OBJECTIVE

To investigate the association between genus beta human papillomaviruses and the incidence of non-melanocytic skin cancer in the general population.

DESIGN

Population based case-control study.

SETTING

New Hampshire, USA.

PARTICIPANTS

2366 skin cancer cases and controls from the general population aged 25 to 74 years (663 squamous cell carcinoma, 898 basal cell carcinoma, 805 controls), with plasma samples tested for L1 antibodies to 16 genus beta human papillomaviruses by multiplex serology.

MAIN OUTCOME MEASURES

Odds ratios for squamous cell carcinoma and basal cell carcinoma associated with seropositivity to beta human papillomaviruses.

RESULTS

Squamous cell carcinoma, but not basal cell carcinoma, cases had a higher prevalence of each of the individual beta human papillomaviruses assayed compared with controls. The odds ratios for squamous cell carcinoma increased with the number of beta types positive (odds ratio for one type positive 0.99 (95% confidence interval 0.74 to 1.33); two to three types positive 1.44 (1.03 to 2.01); four to eight types positive 1.51 (1.03 to 2.20); more than eight types positive 1.71 (1.12 to 2.62); P for trend (categorical)<0.001; P for trend (continuous)=0.003). With limited statistical power, the association was stronger among long term users of systemic glucocorticoids (odds ratio 3.21, 1.22 to 8.44) than among non-users (1.23, 0.97 to 1.55).

CONCLUSIONS

These findings support a relation between genus beta human papillomavirus infection and the incidence of squamous cell carcinoma of the skin in the general population, as well as potential enhancement of risk by immunosuppression.

Lack of association between the presence and persistence of betapapillomavirus DNA in eyebrow hairs and betapapillomavirus L1 antibodies in serum

Betapapillomavirus (betaPV) DNA and seroresponses are highly prevalent in the general population and both are frequently used as infection markers in epidemiological studies to elucidate an association with cutaneous squamous cell carcinoma (SCC). Little is known about the natural history of betaPV infection and the aspects of infection that drive antibody responses. To investigate the relationship between these markers, this study assessed whether the presence or persistence of betaPV DNA in eyebrow hairs and L1 antibodies of the same betaPV type co-occurred more frequently than would be expected by chance in both a cross-sectional assessment and a longitudinal study. betaPV DNA in plucked eyebrow hairs and L1 antibodies in serum were measured in 416 participants of the Australian community-based Nambour Skin Cancer Study in 1996. Similar data were available for a subset of 148 participants in 2003. Observed co-occurrence of betaPV DNA and antibodies was compared with expected values based on prevalence. A case-wise concordance index was used to calculate the overall concordance of betaPV DNA and antibodies of the same type. No significant associations were found between the presence or persistence of betaPV DNA and antibody responses. The age and sex of the host did not influence the association, and nor did SCC status or a history of sunburns. It was concluded that betaPV antibody responses in adults are not primarily driven by betaPV infection as measured in eyebrow hairs. Other factors, such as viral load, may play a more pivotal role in the induction of detectable seroresponses.

Betapapillomavirus infection profiles in tissue sets from cutaneous squamous cell-carcinoma patients

Human papillomaviruses from the genus beta (betaPV) are a possible cause of cutaneous squamous cell carcinoma (SCC). We compared the betaPV infections in SCC and in sets of cutaneous tissues collected from a series of individual SCC patients to determine concordance and to assess the adequacy of eyebrow hairs as noninvasive markers of betaPV infection. Biopsies of SCC tumors, perilesional tissue, normal skin from the mirror image of nonfacial SCC and plucked eyebrow hairs were collected from 21 patients with incident SCC living in Queensland, Australia. These were tested for the presence of DNA from 25 different betaPV types. Overall prevalence of betaPV was high in every sample type, ranging from 81% to 95%. The median number of types was significantly higher in the SCC tumour (6), perilesional skin (5) and eyebrow hairs (5) than in normal skin (2). Comparing SCC tissue with other sample types within patients showed 63 overlapping infections with eyebrow hairs (71%; 95% CI: 60-80); 56 with perilesional skin samples (63%; 95% CI: 52-73) and 23 with normal skin samples (26%; 95% CI: 17-36). The sensitivity of eyebrow hair testing for detection of betaPV in the tumor was 82% (95% CI: 57-96) with concordance defined as 50% of betaPV types in common and 29% (95% CI: 10-56) for 100% concordance. These findings support the concept that perilesional skin represents an area of field change involving betaPV preceding SCC development and indicate that eyebrow hairs can serve to some degree as an easily collected marker of tumor betaPV status in epidemiological studies.

A case-control study of cutaneous squamous cell carcinoma among Caucasian organ transplant recipients: the role of antibodies against human papillomavirus and other risk factors

A case-control study was conducted in 140 people with histology proven cutaneous squamous cell carcinoma (SCC) and 454 controls, nested within 2 cohorts of organ transplant recipients (OTR) recruited in London and Oxford between 2002 and 2006. All participants had a skin examination, completed a questionnaire and had serum tested for antibodies against the L1 antigen of 34 HPV types using Luminex technology. SCC was more common in men than women (odds ratio [OR] = 1.7, 95% confidence interval [CI]: 1.1-2.8, p = 0.02) and in people with susceptibility to burn easily (OR = 3.0, 95%CI: 1.9-4.8; p < 0.001). The risk increased with increasing age (p-trend < 0.001), increasing time since transplant (p-trend < 0.001), increasing self-reported number of sunburns as a child (p-trend < 0.001) and with the presence of viral warts (p < 0.001). As expected, antibodies against HPV 16 were associated with a self-reported history of an abnormal cervical smear among women (OR 5.1, 95%CI: 2.6-10.2) and antibodies against HPV 6 were associated with a self-reported history of genital warts (OR 4.0, 95%CI: 2.2-7.2). However, no clear associations between any of the HPV types examined (including cutaneous betaHPVs) and SCC were identified. For example, the seroprevalence of HPV 5 was 15% among cases and 9% among controls (p = 0.09) and the seroprevalence of HPV 8 was 23% among cases and 21% among controls (p = 0.6). Nor was seropositivity to multiple types associated with SCC. These serological data do not provide evidence for a role for HPV in the aetiology of cutaneous SCC among OTR in two UK-based populations.

Presence of beta human papillomaviruses in nonmelanoma skin cancer from organ transplant recipients and immunocompetent patients in the West of Scotland

BACKGROUND

Nonmelanoma skin cancer (NMSC) has been linked to cutaneous human papillomaviruses of the genus beta (betaPV).

OBJECTIVES

We sought to assess the presence of betaPV in NMSC biopsies from a group of Scottish skin cancer patients, both immunocompetent (IC) patients and immunosuppressed (IS) organ transplant recipients.

METHODS

One hundred and twenty-one paraffin-embedded skin tumours (27 actinic keratosis, 41 intraepidermal carcinoma, 53 squamous cell carcinoma) and 11 normal skin samples were analysed for the presence of betaPV by a polymerase chain reaction-reverse hybridization assay designed to detect the presence of the 25 known betaPV genotypes.

RESULTS

In IC patients, betaPV was detected in 30 of 59 (51%) tumours and two of 11 (18%) normal skin samples (P = 0.046). In IS patients, betaPV was found in 27 of 62 (44%) tumours; no normal skin samples were available for comparison. The most frequently found genotypes were HPV-24, HPV-15 and HPV-38. Of those tumours infected with betaPV, 28 of 57 (49%) were infected with more than one genotype (range 2-8). Tumours from IS patients were from a younger age group (mean age 57.4 years) than IC patients (mean age 73.8 years). Multiple infections were more common in tumours from IC patients (21 of 30; 70%) compared with those from IS patients (seven of 27; 26%) (P < 0.001). In the IC group, age did not appear to influence the distribution of single and multiple infections whereas in IS patients the proportion of multiple infections to single infections increased with age. There were no multiple infections in normal skin.

CONCLUSIONS

A wide spectrum of betaPV types was detected in our samples. Further characterization of betaPV in vivo is needed in order to determine the mechanisms by which the virus contributes to cutaneous carcinogenesis.

Seroprevalence of 34 human papillomavirus types in the German general population

The natural history of infections with many human papillomavirus (HPV) types is poorly understood. Here, we describe for the first time the age- and sex-dependent antibody prevalence for 29 cutaneous and five mucosal HPV types from 15 species within five phylogenetic genera (alpha, beta, gamma, mu, nu) in a general population. Sera from 1,797 German adults and children (758 males and 1,039 females) between 1 and 82 years (median 37 years) were analysed for antibodies to the major capsid protein L1 by Luminex-based multiplex serology. The first substantial HPV antibody reactions observed already in children and young adults are those to cutaneous types of the genera nu (HPV 41) and mu (HPV 1, 63). The antibody prevalence to mucosal high-risk types, most prominently HPV 16, was elevated after puberty in women but not in men and peaked between 25 and 34 years. Antibodies to beta and gamma papillomaviruses (PV) were rare in children and increased homogeneously with age, with prevalence peaks at 40 and 60 years in women and 50 and 70 years in men. Antibodies to cutaneous alpha PV showed a heterogeneous age distribution. In summary, these data suggest three major seroprevalence patterns for HPV of phylogenetically distinct genera: antibodies to mu and nu skin PV appear early in life, those to mucosal alpha PV in women after puberty, and antibodies to beta as well as to gamma skin PV accumulate later in life.

Exposure profiles and human papillomavirus infection in skin cancer: an analysis of 25 genus beta-types in a population-based study

An increasing number of studies report that genus beta human papillomaviruses (HPVs) are associated with skin cancer, with suggestions of specificity for squamous cell carcinoma (SCC) of the skin. We have conducted a systematic examination of HPV DNA in tumors from immunocompetent hosts, including SCC and basal cell carcinoma (BCC), using a highly sensitive methodology and population-based samples to test the hypothesis that a differential prevalence of beta-HPVs exists between SCC (n=101) and BCC (n=101) tumors. When testing for all known beta-HPV types, we found no significant difference in HPV prevalence between the two histologies. However, SCC lesions were significantly more likely to be infected with HPV genus beta-species 1 (includes types 5 and 8), than BCC samples (P=0.01); this difference was not observed for any other species. A histologic difference was also observed for those HPV types previously reported to be important in skin cancer (P=0.003). SCC samples showed a higher rate of infectivity (that is, were positive for multiple types) than BCC tumors (P=0.02). These data highlight the potential importance of various genus beta-HPV types, in particular genus beta-species 1 in SCC, and support the hypothesis of a behavioral difference of the virus within the two major histological skin cancers.

Reactivity pattern of 92 monoclonal antibodies with 15 human papillomavirus types

Most anti-human papillomavirus (HPV) capsid antibody assays are based on virus-like particles (VLP). We evaluated glutathione S-transferase (GST)-L1 fusion proteins as ELISA antigens for determining type specificity and cross-reactivity of 92 VLP-specific monoclonal antibodies (mAb) generated against nine mucosal alpha papillomavirus types of species 7, 9 and 10. The antibody panel included 25 new mAb, and 24 previously published mAb are further characterized. We determined the cross-reactivity patterns with 15 different HPV types representing 6 species (alpha1, 2, 4, 7, 9 and 10) and neutralization and cross-neutralization properties with HPV types 6, 11, 16, 18 and 45. Eighty-nine (97 %) of the antibodies including 34, 71 and 14 recognizing neutralizing, conformational and linear epitopes, respectively, reacted with the GST-L1 protein of the HPV type used as immunogen, with log titres ranging from 2.0 to 7.3. Of these 89 antibodies, 52 % were monotypic, 20 % showed intra-species and 28 % inter-species cross-reactivity. Log neutralization titres to the immunogen HPV ranged from 1.7 to 5.6. A single cross-neutralizing mAb (H6.L12) was found. ELISA titres were always higher than neutralization titres. All neutralizing epitopes were conformational and mostly type-specific. Our data show that bacterially expressed, affinity-purified GST-L1 fusion proteins display a broad variety of epitopes and thus are well suited for detection of HPV antibodies. Cross-reactivity is associated with linear as well as conformational epitopes. Distantly related mucosal and skin alpha papillomaviruses share some conformational epitopes and the phylogenetic L1-based species definition may not define a serological unit since no species-specific epitope was found.

Prophylaktische und therapeutische HPV-Impfstoffe

Papilloma viruses (PV) have been known to cause benign and malignant tumors in animals for more than 100 years. It took over 20 years to win general acceptance for their causative role in anogenital carcinomas in humans in particular in cervial carcinoma. Extensive research has led to the development of a prophylactic vaccine which is now commercially available. It remains to be investigated if HPV-specific therapeutic vaccines can be developed.

A prospective pilot study of antibodies against human papillomaviruses and cutaneous squamous cell carcinoma nested in the Oxford component of the European Prospective Investigation into Cancer and Nutrition

In a prospective pilot study nested in the EPIC-Oxford cohort, we examined the seroprevalence of antibodies against the L1 antigen of 38 human papilloma virus (HPV) types among 39 cases of cutaneous squamous cell carcinoma (SCC) for whom plasma was collected prior to diagnosis (incident) and 80 controls. Fifteen cases having already developed SCC at blood collection (prevalent) were also tested. There were no statistically significant differences in the seroprevalence of antibodies against any of the HPV types examined between incident cases and controls, nor was there a difference in the seroprevalence of multiple infections. However, consistent with results from published case-control studies, the seroprevalence of many beta-HPV types was higher among prevalent cases than among either incident cases or controls. For example the seroprevalence of antibodies against HPV-8 was 20% (16/80) in controls, 23% (9/39) among incident cases and 40% (6/15) among prevalent cases. Among the incident cases only, the seroprevalence was 16% (5/32) among those for whom blood was collected 18+ months prior to diagnosis, but 57% (4/7) among those for whom diagnosis was within 18 months of blood collection, a pattern seen for many of the HPV types. This might suggest that if HPV is involved in the aetiology of SCC, the process occurs close to the time of diagnosis, or that the antibody response observed in people with SCC is a consequence of tumor formation. Further and larger prospective studies are needed to clarify the role of HPV in the aetiology of cutaneous SCC.

Human Papillomavirus Infection and Incidence of Squamous Cell and Basal Cell Carcinomas of the Skin

BACKGROUND

Although infection with human papillomaviruses (HPVs) is a major risk factor for several epithelial cancers, an etiologic relationship between HPV and keratinocyte cancers, such as squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs), remains unclear.

METHODS

In a population-based case-control study of 252 SCC case patients, 525 BCC case patients, and 461 control subjects, we used multiplex serology to detect antibodies in plasma samples against 16 HPV types from phylogenetic genera alpha, beta, and mu. Multiplex serology is a new method that is based on fluorescent bead technology and allows simultaneous detection of antibodies against up to 100 different in situ affinity-purified recombinant HPV proteins. Data on sun sensitivity, outdoor exposure, and other risk factors for keratinocyte cancers were collected through personal interviews. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated via unconditional logistic regression models.

RESULTS

Overall, we detected HPV antibodies more frequently in SCC patients than in control subjects (OR = 1.6, 95% CI = 1.2 to 2.3), but we found no difference in HPV seropositivity between BCC case patients and control subjects (OR = 0.8, 95% CI = 0.6 to 1.1). Among HPV types, seropositivity to HPV types in genus beta (OR = 1.5, 95% CI = 1.0 to 2.1), particularly HPV 5 (OR = 1.8, 95% CI = 1.0 to 3.1), was associated with SCC risk. Individuals with tumors on chronically sun exposed sites were more likely to be seropositive for beta HPV types than individuals with SCC at other anatomic sites. The highest SCC risk was associated with positivity for multiple HPV types and, among individuals seropositive for HPV beta, a tendency to sunburn; however, the associations had limited statistical precision.

CONCLUSIONS

Our findings support a role for HPV types from the genus beta in the pathogenesis of SCC.

Clinicopathologic features of skin cancer in organ transplant recipients: A retrospective case-control series

BACKGROUND

Non-melanoma skin cancers (NMSCs) are increased in organ transplant recipients, but transplant and immunocompetent squamous and basal cell carcinomas (SCCs, BCCs) have not been compared previously in a single-center study.

OBJECTIVE

To compare clinicopathologic features of transplant and immunocompetent NMSCs.

METHODS

Consecutive transplant NMSCs (60 SCCs, 100 BCCs) and immunocompetent NMSCs (40 SCCs, 125 BCCs) presenting between 1995-1997.

RESULTS

Transplant patients were 15 years younger at time of NMSC diagnosis compared with immunocompetent individuals, and transplant tumors were often more multiple and extracephalic. Spindle cell morphology was more common in transplant SCCs, a superficial component was more common in transplant BCCs, and histologic features of HPV infection were overrepresented in transplant tumors. Outcome was worse for transplant SCCs but not transplant BCCs.

LIMITATIONS

Histologic features required to identify HPV infection have not been validated.

CONCLUSIONS

These findings have direct implications for clinical care. The increased frequency and distribution of transplant NMSCs underscore the importance of whole-body surveillance. Transplant SCCs, particularly those with diffuse spindle cell change, may require more aggressive management, whereas transplant BCCs do not. Finally, our data support differences in the pathogenesis of transplant NMSC, which may influence future preventive and therapeutic strategies.

Apoptosis induced by ultraviolet B in HPV-immortalized human keratinocytes requires caspase-9 and is death receptor independent

Ultraviolet B (UVB) induces both apoptosis and skin cancer. We found that human keratinocytes (KC) immortalized by Human Papillomavirus (HPV)16 E6/E7 were sensitized to UVB-induced apoptosis, possibly representing a transient regression-prone precancerous stage equivalent to actinic keratosis. To further examine which caspases are apical and essential, we utilized retroviral constructs expressing dominant-negative caspase-9 (caspase-9-DN) or Fas-associated protein with death domain (FADD)-DN as well as caspase inhibitor peptides. Caspase-9-DN and zLEHD-fmk both suppressed caspase-9, -3, and -8 activity after UVB exposure, as well as proteolytic processing of procaspase-3 into its active form, DNA fragmentation factor 45 cleavage, and internucleosomal DNA fragmentation. By contrast, stable expression of FADD-DN in HPV-immortalized KC did not inhibit UVB-induced activation of caspases-9, -3, and -8 nor downstream apoptotic events, although inhibition of caspase-8 with zIETD-fmk attenuated apoptosis. This study indicates that caspase-9 activation is upstream of caspases-3 and -8 and that UVB-induced apoptosis in HPV-immortalized human KC is death receptor (DR) independent and requires both caspase-9 upstream and caspase-8 downstream for maximal apoptosis. These studies further indicate that cell type as well as transformation state determine the sensitivity and mode of cell death (DR vs. mitochondrial apoptotic pathways) in response to UVB and explain the high regression rates of premalignant lesions.

Human papillomavirus gene expression in cutaneous squamous cell carcinomas from immunosuppressed and immunocompetent individuals

Epidermodysplasia verruciformis (EV)-type human papillomavirus (HPV) DNA have been detected by PCR in squamous cell carcinomas (SCC) from both organ transplant recipients (OTR) and immunocompetent individuals. Their role in skin cancer remains unclear, and previous studies have not addressed whether the viruses are transcriptionally active. We have used in situ hybridization to investigate the transcriptional activity and DNA localization of HPV. EV-HPV gene transcripts were demonstrated in four of 11 (36%) OTR SCC, one of two (50%) IC SCC, and one of five (20%) OTR warts positive by PCR. Viral DNA co-localized with E2/E4 early region gene transcripts in the middle or upper epidermal layers. Non-EV cutaneous HPV gene transcripts were demonstrated in one of five (20%) OTR SCC and four of 10 (40%) OTR warts. In mixed infections transcripts for both types were detected in two of six (33%) cases. Our results provide evidence of EV-HPV gene expression in SCC; although only a proportion of tumors were positive, the similarly low transcriptional activity in warts suggests this is an underestimate. These observations, together with emerging epidemiological and functional data, provide further reason to focus on the contribution of EV-HPV types to the pathogenesis of cutaneous SCC.

Id2 protein is selectively upregulated by UVB in primary, but not in immortalized human keratinocytes and inhibits differentiation

Solar ultraviolet B (UVB) acts as both an initiator and promoter in models of multistage skin carcinogenesis. We found that, whereas UVB induces apoptosis in human papillomavirus-16 E6/7-immortalized keratinocytes, it inhibits markers of differentiation in human foreskin keratinocytes (HFK). Potential mechanisms for this differential response were examined by DNA microarray, which revealed that UVB alters the expression of three of the four human inhibitor of differentiation/DNA binding (Id) proteins that comprise a class of helix-loop-helix family of transcription factors involved in proliferation, differentiation, apoptosis, and carcinogenesis. These results were verified by RT-PCR and immunoblot analysis of control and UVB-irradiated primary and immortalized keratinocytes. Whereas Id1 was downregulated in both cell types, Id2 expression was upregulated in primary HFK, but not immortalized cells. In contrast, Id3 expression was significantly increased only in immortalized cells. The differential expression pattern of Id2 in response to UVB was recapitulated in reporter constructs containing the 5' regulatory regions of this gene. Id2 promoter activity increased in response to UVB in HFK, but not in immortalized cells. To identify the regulatory elements in the Id2 promoter that mediate transcriptional activation by UVB in HFK, promoter deletion/mutation analysis was performed. Deletion analysis revealed that transactivation involves a 166 bp region immediately upstream to the Id2 transcriptional start site and is independent of c-Myc. The consensus E twenty-six (ETS) binding site at -120 appears to mediate UVB transcriptional activation of Id2 because point mutations at this site completely abrogated this response. Chromatin immunoprecipitation and electrophoretic mobility-shift assays verified that the Id2 promoter interacts with known Id2 promoter (ETS) binding factors Erg1/2 and Fli1, but not with c-Myc; and this interaction is enhanced after UVB exposure. Similar to the effects of UVB exposure, ectopic expression of Id2 protein in primary HFK resulted in inhibition of differentiation, as shown by decreased levels of the terminal differentiation marker keratin K1 and inhibition of involucrin crosslinking. Reduction of Id2 expression by small interfering RNAs attenuated the UVB-induced inhibition of differentiation in these cells. These results suggest that UVB-induced inhibition of differentiation of primary HFK is at least, in part, due to the upregulation of Id2, and that upregulation of Id2 by UVB might predispose keratinocytes to carcinogenesis by preventing their normal differentiation program.

Detection of epidermodysplasia verruciformis-associated human papillomavirus DNA in nongenital seborrhoeic keratosis

BACKGROUND

DNA of epidermodysplasia verruciformis (EV)-associated human papillomaviruses (HPVs) has been widely detected in lesions of malignant skin tumours, benign tumours and other proliferative diseases of epithelial origin.

OBJECTIVES

To investigate the presence of EV-associated HPV DNA in nongenital seborrhoeic keratosis (SK) and to elucidate the prevalence of distinct HPV genotypes.

METHODS

We investigated HPV DNA in 55 nongenital SK biopsies, which were compared with 48 normal skin biopsies (healthy controls) using a nested polymerase chain reaction (PCR) using consensus primers CP65/CP70 and CP66/CP69. The positive PCR products were retracted and used to prepare recombination clones with T-vector. Distinct clones were analysed with endonucleases, and HPV genotypes were identified by direct sequencing.

RESULTS

EV-associated HPV DNA was detected in 42 of 55 (76%) nongenital SK biopsies vs. only 13 of 48 (27%) healthy controls (chi2 = 22.087; P < 0.005). The prevalence was higher in patients with more than five lesions than in those with only one lesion (P < 0.05). Ten distinct HPV genotypes were detected in the nongenital SK biopsies: HPV 20, 23, 5, renal transplant recipient (RTR) X7, HPV 17, 37, 17b, RTRX4, RTRX4b and strain SK3. HPV 20 was found in 26 of 42 (62%) positive specimens, followed by HPV 23 (11 of 42, 26%) and HPV 5 (six of 42, 14%). Existence of multiple HPV genotypes was observed in 12 of 42 (29%) positive specimens. In healthy controls, five genotypes of EV-associated HPV (HPV 20, 23, 5, 17 and RTRX4) were detected, with the same predominant genotype of HPV 20 (five of 13, 38%). Several distinct HPV genotypes were found to coexist in four of 13 (31%) positive specimens.

CONCLUSIONS

This study provides some evidence that EV-associated HPVs might play a part in the pathogenesis of nongenital SK.

Human papillomaviruses and skin cancer

Cutaneous epidermodysplasia verruciformis (EV)-associated human papillomaviruses (HPVs) are found frequently in skin cancers especially in immunosuppressed people. They are also detectable in the normal skin and hair follicles of a proportion of individuals who have no immune defect. The available evidence to link HPVs causally with skin carcinogenesis is not conclusive, but includes epidemiological, molecular and immunological studies.

Development of Skin Tumors in Mice Transgenic for Early Genes of Human Papillomavirus Type 8

The cutaneous human papillomavirus (HPV) 8 is clearly involved in skin cancer development in epidermodysplasia verruciformis patients and its early genes E2, E6, and E7 have been implicated in cell transformation in vitro. To examine the functions of these genes in vivo we integrated the complete early region of HPV8 into the genome of DBA/Bl6 mice. To target their expression to the basal layer of the squamous epithelia the transgenes were put under the control of the keratin-14 promoter. Transgenic mice were back-crossed for up to six generations into both FVB/N and Bl6 mouse strains. Whereas none of the HPV8 transgene-negative littermates developed lesions in the skin or any other organ, 91% of HPV8-transgenic mice developed single or multifocal benign tumors, characterized by papillomatosis, acanthosis, hyperkeratosis, and varying degrees of epidermal dysplasia. Squamous cell carcinomas developed in 6% of the transgenic FVB/N mice. Real-time reverse transcription-PCR showed highest expression levels for HPV8-E2, followed by E7 and E6. There was no consistent difference in relative viral RNA levels between healthy or dysplastic skin and malignant skin tumors. Whereas UV-induced mutations in the tumor suppressor gene p53 are frequently detected in human skin carcinomas, mutations in p53 were not observed either in the benign or malignant mouse tumors. Nonmelanoma skin cancer developed in HPV8-transgenic mice without any treatment with physical or chemical carcinogens. This is the first experimental proof of the carcinogenic potential of an epidermodysplasia verruciformis-associated HPV-type in vivo.

Chapter 12: Human papillomavirus technologies

Currently, human papillomavirus (HPV) DNA tests validated in large trials and epidemiological studies are the hybrid capture second-generation (HC2) HPV DNA assay and a variety of polymerase chain reaction (PCR) protocols employing degenerate or consensus primers. This article describes the currently available technology for HPV detection and discusses novel technologies and their potential for large-scale screening. Ideally, an HPV test should allow detection of multiple HPV types, identify individual types, and provide quantitative information about the viral load of each individual type found. Moreover, it should be easy to perform, be highly reproducible, with a high specificity and sensitivity, and amenable for high throughput analysis and automation. Because we do not yet fully understand the true value of viral load and the biological relevance of the different HPV types, any HPV test should be able to detect the clinically relevant high-risk types with a sufficient sensitivity of at least 10 000 genome copies per sample. To validate the different current and future test systems and to compare inter-laboratory performance we urgently need reference samples, validated reagents, and standardized protocols.

Chapter 8: Human papillomavirus and skin cancer

A high prevalence of human papillomavirus (HPV) DNA, particularly in squamous cell skin carcinoma of immunosuppressed but also of immunocompetent patients, has renewed great interest in a possible etiologic role of HPV in nonmelanoma skin cancer. It is difficult, however, to interpret these findings against a background of low-level infections with multiple HPV types from supergroup B (HPV4-related and epidermodysplasia verruciformis [EV] HPV), probably acquired by everyone early in and throughout life. Thus far, no high-risk HPV types have been identified. Because of the low copy numbers of HPV DNA in skin cancers, probably not every tumor cell contains a viral genome, which is compatible with cutaneous HPV being possibly important for tumor initiation and progression, but not for maintenance of the malignant phenotype. The question with regard to high-risk types should, therefore, be readdressed in case-control studies on the basis of serology, which can reveal viral activities over years. The viruses lingering in all people are apparently activated by sunlight (UV) exposure, by immunosuppression, and by hyperproliferation of the epithelium (psoriasis) and/or in the specific genetic background of the host (EV). It is intriguing that most of these factors are established risk factors in skin carcinogenesis. The weak transforming activity of cutaneous HPV in vitro compared with the transforming activity of genital HPV may explain the need for activators and synergistic factors. The antiapoptotic activities of E6 proteins of cutaneous HPV could be relevant to oncogenesis in the interplay with UV exposure. Prospective studies should determine the kinetics of HPV activation relative to tumor development.

The imidazoquinolines and their place in the therapy of cutaneous disease

The imidazoquinolines arose from efforts to develop a nucleoside analogue. Although molecularly similar to nucleosides, the imidazoquinolines did not have nucleoside-like activity. However, the imidazoquinolines induced immune modulatory cytokines, in part, because of their ability to activate toll receptors (TLR)s. Imiquimod, the first FDA-approved imidazoquinoline, has been marketed as a 5% cream, which is approved for the therapy of genital warts. The advantage of imiquimod therapy over other therapies for genital warts is the decrease in recurrence rate with the establishment of an adaptive immunological response or immunological memory/surveillance response. As tumours and viral infections are handled similarly by the immune system, there has been great interest in the use of topical imiquimod for the treatment of cutaneous neoplasms, particularly non-melanoma skin cancers. Future efforts in imidazoquinoline research is focused around the development of analogues with modifications in the immunological profiles, potency and penetration parameters that better focus these new analogues for the therapy of specific intracellular infections and neoplasms, as well as the development of imidazoquinolines for conditions related either directly or indirectly to patterns of immune dysregulation.

The role of p53 in the immunobiology of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma is typically characterized by the over-expression of the tumour suppressor protein p53. Considerable evidence suggests that immune competence is important in the control of cutaneous SCC. We discuss the immunobiology of p53 and its relevance to cutaneous SCC, including the potential interaction with human papillomavirus.

HPV-16 E6/7 immortalization sensitizes human keratinocytes to ultraviolet B by altering the pathway from caspase-8 to caspase-9-dependent apoptosis

UVB from solar radiation is both an initiating and promoting agent for skin cancer. We have found that primary human keratinocytes undergo an apoptotic response to UVB. To determine whether these responses are altered during the course of immortalization, we examined markers of apoptosis in primary human foreskin keratinocytes (HFK) transduced with either a retroviral vector expressing the E6 and E7 genes of HPV-16 or with empty vector alone (LXSN-HFK). Whereas LXSN-HFK as well as early passage keratinocytes expressing HPV-16 E6 and E7 (p7 E6/7-HFK) were both moderately responsive to UVB irradiation, late passage-immortalized keratinocytes (p27 E6/7-HFK) were exquisitely sensitive to UVB-induced apoptosis. After exposure to UVB, enhanced annexin V-positivity and internucleosomal DNA fragmentation were observed in p27 E6/7-HFK compared with either LXSN- or p7 E6/7-HFK. Caspase-3 fluorometric activity assays as well as immunoblot analysis with antibodies to caspase-3 and poly(ADP-ribose) polymerase revealed elevated caspase-3 activity and processing at lower UVB doses in p27 E6/7-HFK compared with LXSN- or p7 E6/7-HFK. In addition, the caspase inhibitor DEVD-CHO reduced the apoptotic response and increased survival of all three HFK types. Immunoblot analysis revealed that caspase-8 was activated in all three cell types, but caspase-9 was only activated in p27 E6/7-HFK. Cell cycle analysis further showed that only p27 E6/7-HFK exhibit G(2)/M accumulation that is enhanced by UVB treatment. This accumulation was associated with a rapid down-regulation of Bcl-2 in these cells. The immortalization process subsequent to the expression of HPV E6 and E7 may therefore determine UVB sensitivity by switching the mode of apoptosis from a caspase-8 to a Bcl-2-caspase-9-mediated pathway of apoptosis.

Human papillomaviruses and non-melanoma skin cancer

Epidemiological and experimental studies have overwhelmingly confirmed human papillomaviruses as important causal agents in anogenital carcinogenesis. A role for human papillomaviruses has also been proposed in a diverse range of other malignancies, and particular interest has focused on non-melanoma skin cancer, the commonest malignancy in fair-skinned populations worldwide. Although the evidence for this is considerably less convincing than for anogenital cancer, important epidemiological and functional data have emerged over the past year that have furthered our understanding of the possible contribution of human papillomaviruses to skin cancer. Epidemiological human papillomavirus DNA detection studies have shown associations with non-melanoma skin cancer, but have also emphasized the ubiquity of epidermodysplasia verruciformis human papillomavirus types in normal skin, hair follicles and benign hyperproliferative disorders, as have seroepidemiological approaches. Functional investigations have demonstrated mechanistically relevant interactions between the virus and ultraviolet radiation, host cytokines and cellular proteins including p53 and the pro-apoptotic protein Bak. Taken together, these data have advanced our understanding of the contribution of human papillomaviruses to malignant transformation in cutaneous keratinocytes, but further research is required before a causal association between human papillomaviruses and skin cancer is reliably confirmed.

Topical immunomodulators--progress towards treating inflammation, infection, and cancer

Immunomodulators include both immunostimulatory and immunosuppressive agents. Only recently have the basic mechanisms of topical immunotherapy been elucidated. Besides topical contact sensitisers (eg, diphencyprone or dinitrochlorobenzene), newer agents of the imidazoquinoline family such as imiquimod and resiquimod act by inducing cytokine secretion from monocytes or macrophages (interferon-alpha, interleukin-12, tumour-necrosis factor-alpha). The locally generated immune milieu leads to a Th1-dominance and cell-mediated immunity that have been used clinically to treat viral infections such as human papillomavirus (HPV), herpes simplex virus (HSV), mollusca, and cancerous lesions including initial squamous cell and basal cell carcinoma in immunocompetent and immunosuppressed patients. While these agents improve antigen-presentation by dendritic cells, they also act on B cells and lead to the synthesis of antibodies such as IgG2a much like the recently discovered immunostimulatory CpG-sequences that stimulate innate immunity. These sequences act as "danger signals" since they occur in bacterial and viral DNA, but are selectively methylated and inactivated in the mammalian genome. They share the induction of the same cytokines as imidazoquinolines but they show different magnitudes and kinetics of response. Topical immunotherapy with immunostimulatory agents shows potential for effective and patient-friendly treatment of inflammatory, infectious, and cancerous skin diseases. Immunoenhancers such as imdazoquinolines and CpG-sequences also have adjuvant properties that could improve conventional (protein) and DNA vaccination against cancer, atopy, and allergies.

Human papillomavirus infection in Netherton's syndrome

BACKGROUND

Netherton's syndrome (NS) is a hereditary disorder with dermatological signs (e.g. ichthyosis) and a complex immunological dysfunction. In immunodeficient individuals human papillomavirus (HPV) types are associated with carcinomas on non-mucosal sites.

OBJECTIVES

To study the presence of HPV infection in different skin lesions of three male NS patients and to investigate a possible association between HPV and malignancies in NS.

METHODS

Patient 1 had extraordinary widespread multiple skin carcinomas on sunlight-exposed areas, as well as common viral warts. Patient 2 showed disseminated viral plane warts that resolved spontaneously, and patient 3 was free of skin lesions suspicious for HPV infection; only pseudoepitheliomatous wart-like lesions as a symptom of ichthyosis were apparent. We performed nested polymerase chain reaction analysis of DNA from benign and malignant skin lesions and HPV-8 serology in these three patients.

RESULTS

Antibodies to HPV-8 were not detectable in our patients; however, seven of 22 (31%) biopsies of the three NS patients were positive for HPV DNA. Epidermodysplasia verruciformis (EV) -associated HPV types and normal cutaneous types (HPV-2, HPV-28) were detected. Interestingly, only the patient with cutaneous carcinomas harboured, preferentially in malignant lesions, EV-HPV types (HPV-19, 23, 38 and HPV-RTRX9, closely related to EV-HPVs), whereas plane warts of patient 2 were positive for HPV-28. The pseudoepitheliomatous skin lesions were HPV-DNA negative in all investigated probes.

CONCLUSIONS

These data in NS patients further confirm an association of EV-HPVs with non-melanoma skin cancer (NMSC) and suggest a possible carcinogenic role similar to that assumed for NMSC in transplant recipients. A complex immunological disorder facilitating EV-HPV infection, negative HPV serology and photochemotherapy may all have contributed to the unusual occurrence of multiple cancers in one of our NS patients.