Peter Sehr

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.

Human Papillomavirus Type 16 L1 Capsomeres Induce L1-Specific Cytotoxic T Lymphocytes and Tumor Regression in C57BL/6 Mice

ABSTRACT We analyzed capsomeres of human papillomavirus type 16 (HPV16) consisting of the L1 major structural protein for their ability to trigger a cytotoxic T-cell (CTL) response. To this end, we immunized C57BL/6 mice and used the L1165-173 peptide for ex vivo restimulation of splenocytes prior to analysis (51Cr release assay and enzyme-linked immunospot assay [ELISPOT]). This peptide was identified in this study as a Db-restricted naturally processed CTL epitope by HPV16 L1 sequence analysis, major histocompatibility complex class I binding, and 51Cr release assays following immunization of C57BL/6 mice with HPV16 L1 virus-like particles (VLPs). HPV16 L1 capsomeres were obtained by purification of HPV16 L1 lacking 10 N-terminal amino acids after expression in Escherichia coli as a glutathione S-transferase fusion protein (GST-HPV16 L1ΔN10). Sedimentation analysis revealed that the majority of the purified protein consisted of pentameric capsomeres, and assembled particles were not observed in minor contaminating higher-molecular-weight material. Subcutaneous (s.c.) as well as intranasal immunization of C57BL/6 mice with HPV16 L1 capsomeres triggered an L1-specific CTL response in a dose-dependent manner as measured by ELISPOT and 51Cr release assay. Significant reduction of contaminating bacterial endotoxin (lipopolysaccharide) from the capsomere preparation did not diminish the immunogenicity. Antibody responses (serum and vaginal) were less robust under the experimental conditions employed. In addition, s.c. vaccination with HPV16 L1 capsomeres induced regression of established tumors expressing L1 determinants (C3 tumor cells). Our data demonstrate that capsomeres are potent inducers of CTL responses similar to completely assembled T=7 VLPs. This result is of potential relevance for the development of (combined prophylactic and therapeutic) HPV-specific vaccines, since capsomeres can be produced easily and also can be modified to incorporate heterologous sequences such as early HPV proteins.

Serological association of beta and gamma human papillomaviruses with squamous cell carcinoma of the skin.

Backgroundu2002 Cutaneous human papillomaviruses (HPVs) may play a role in the development of squamous cell carcinomas (SCC) of the skin.

Absence of SV40 antibodies or DNA fragments in prediagnostic mesothelioma serum samples

The rhesus monkey virus Simian Virus 40 (SV40) is a member of the polyomavirus family. It was introduced inadvertently to human populations through contaminated polio vaccine during the years 1956–1963, can induce experimental tumors in animals and transform human cells in culture. SV40 DNA has been identified in mesothelioma and other human tumors in some but not all studies. We tested prediagnostic sera from 49 mesothelioma cases and 147 matched controls for antibodies against the viral capsid protein VP1 and the large T antigen of SV40 and of the closely related human polyomaviruses BK and JC, and for SV40 DNA. Cases and controls were identified among donors to the Janus Serum Bank, which was linked to the Cancer Registry of Norway. Antibodies were analyzed by recently developed multiplex serology based on recombinantly expressed fusions of glutathione‐S transferase with viral proteins as antigens combined with fluorescent bead technology. BKV and JCV specific antibodies cross‐ reactive with SV40 were preabsorbed with the respective VP1 proteins. Sera showing SV40 reactivity after preabsorption with BKV and JCV VP1 were further analyzed in SV40 neutralization assays. SV40 DNA was analyzed by SV40 specific polymerase chain reactions. The odds ratio for being a case when tested positive for SV40 VP1 in the antibody capture assay was 1.5 (95% CI 0.6–3.7) and 2.0 (95% CI 0.6–7.0) when only strongly reactive sera where counted as positive. Although some sera could neutralize SV40, preabsorption with BKV and JCV VP1 showed for all such sera that this neutralizing activity was due to cross‐reacting antibodies and did not represent truly SV40‐specific antibodies. No viral DNA was found in the sera. No significant association between SV40 antibody response in prediagnostic sera and risk of mesothelioma was seen.

Antibody responses to 26 skin human papillomavirus types in the Netherlands, Italy and Australia

Solar UV radiation is the main risk factor for cutaneous squamous cell carcinoma (SCC), but infections with skin human papillomavirus (HPV) types have also been linked to the development of SCC. Little is known about the natural history of these infections and whether the seroprevalence of skin HPV types is affected by ambient or individual levels of sun exposure. This study investigated this by analysing sera for antibodies to 26 skin HPV types from five phylogenetic genera obtained from 807 healthy individuals from the Netherlands, Italy and Australia, countries with strong differences in sunlight intensity. Overall HPV seroprevalence was similar across the three countries (50-57 % for beta-HPV types, 40-48 % for gamma-HPV types), and the most frequent beta-HPV and gamma-HPV types were the same in all countries. The highest seroprevalences for 24 of the 26 skin HPV types were observed in Italy (14 types) and Australia (ten types). Seroprevalence among men was generally higher than among women, and the male sex was significantly associated with both beta-HPV [odds ratio (OR) 2.81, 95 % confidence interval (CI) 1.64-4.82] and gamma-HPV (OR 2.42, 95 % CI 1.40-4.18) antibodies in Australia. The only measure of sun sensitivity or UV exposure significantly associated with skin HPV seroprevalence was found for weekend sun exposure in Australia and beta-HPV antibodies. It was concluded that type spectra and HPV seroprevalence are similar in countries with different sunlight intensity, and that levels of UV exposure do not play a strong role in the development of skin HPV antibodies in this study population.