Isolation of three novel rat and mouse papillomaviruses and their genomic characterization.

Despite a growing knowledge about the biological diversity of papillomaviruses (PV), only little is known about non-human PV in general and about PV mice models in particular. We cloned and sequenced the complete genomes of two novel PV types from the Norway rat (Rattus norvegicus; RnPV2) and the wood mouse (Apodemus sylvaticus; AsPV1) as well as a novel variant of the recently described MmuPV1 (originally designated as MusPV) from a house mouse (Mus musculus; MmuPV1 variant). In addition, we conducted phylogenetic analyses using a systematically representative set of 79 PV types, including the novel sequences. As inferred from concatenated amino acid sequences of six proteins, MmuPV1 variant and AsPV1 nested within the Beta+Xi-PV super taxon as members of the Pi-PV. RnPV2 is a member of the Iota-PV that has a distant phylogenetic position from Pi-PV. The phylogenetic results support a complex scenario of PV diversification driven by different evolutionary forces including co-divergence with hosts and adaptive radiations to new environments. PV types particularly isolated from mice and rats are the basis for new animal models, which are valuable to study PV induced tumors and new treatment options

Papilloomiviiruse transkriptsiooni ja regulaatorvalgu E2 uurimine

Väitekirja elektrooniline versioon ei sisalda publikatsioonePapilloomiviirused on viiruste perekond, mis nakatab nii inimeste kui loomade epiteelrakke ja põhjustab papilloome ehk näsakasvajaid, mis võivad teatud tingimustes areneda halvaloomulisteks kasvajateks. Inimese papilloomiviiruseid on teada üle 200 tüübi ja nad jagatakse kaheks grupiks nende koespetsiifilisuse alusel: limaskesti nakatavad papilloomiviirused ja naharakke nakatavad papilloomiviirused. Naha papilloomiviirused on siiani pälvinud vähem tähelepanu, sest nende võimalik seos nahakasvajatega on tulnud ilmsiks alles viimasel kümnendil. Meie keskendusime oma töös naha papilloomiviirusele HPV5, mida on viimasel ajal hakatud seostama nahakasvajate tekkega, aga mida on siiani ikkagi suhteliselt vähe uuritud. Meie töö tulemusena valmis HPV5 transkriptsiooni kaart, mille iseloomustamiseks me kasutasime inimese sääreluu kasvaja rakuliini U2OS. Selle rakuliini abil õnnestus meil kirjeldada 14 erinevat viiruse mRNAd. Edasises töös keskendusime viirusvalgu E2 uurimisele, mis on põhiline viiruse elutsükli regulaator. E2 valgul on lisaks täispikale valgule veel kaks isovormi, valgu C-terminaalset osa sisaldav E2C ja alternatiivse splaissinguga saadud E8/E2. Me uurisime E2 paiknemist rakus ja leidsime, et lühike E8 valgu järjestus on piisav selleks, et valk suunata raku tuuma. Meile teadaolevalt on see järjestus lühim tuuma suunav järjestus, mis on siiani teada. Tänu proteoomika arengule on siiani leitud üle 200 E2 partnervalgu, millest enamuse funktsioon viiruse elutsüklis on siiani teadmata. Meie leidsime uue E2-ga seonduva rakulise valgu, milleks on tuumamüosiin 1. See on esimene müosiini perekonda kuuluv E2 partnervalk ja katsed näitasid, et tuumamüosiin 1 mõjutab HPV5 DNA paljunemist rakus.Cutaneous papillomaviruses infect human cutaneous epithelium and in most cases these infections pass without symptoms, but in some instances, they can cause lesions and induce squamous cell carcinomas. One of the most prevalent virus types detected in skin cancer is HPV5. We tried to bring through our work more understanding about the properties of these viruses and focused our attention to HPV5 and to the first part of its life-cycle in the cells. We wanted to characterize HPV5 more thoroughly at RNA level and managed to identify HPV transcription map. We also studied papillomavirus main regulator protein E2, which influences all main viral life events. We studied E2 localization in the cell and identified short nuclear targeting signal, that sends proteins to the nucleus. We also found new E2 interaction partner nuclear myosin 1, which influences HPV5 replication

Bovine papillomavirus: old system, new lessons?

No abstract available

Evolutionary variation of papillomavirus E2 protein and E2 binding sites

Background: In an effort to identify the evolutionary changes relevant to E2 function, within and between papillomavirus genera, we evaluated the E2 binding sites (E2BS)s inside the long-control-region (LCR), and throughout the genomes. We identified E2BSs in the six largest genera of papillomaviruses: Alpha, Beta, Gamma, Delta, Lambda, and Xi-papillomaviruses (128 genomes), by comparing the sequences with a model consensus we created from known functional E2BSs (HPV16, HPV18, BPV1). We analyzed the sequence conservation and nucleotide content of the 4-nucleotide spacer within E2BSs. We determined that there is a statistically significant difference in GC content of the four-nucleotide E2BS spacer, between Alpha and Delta-papillomaviruses, as compared to each of the other groups. Additionally, we performed multiple alignments of E2 protein sequences using members of each genus in order to identify evolutionary changes within the E2 protein. Results: When a phylogenetic tree was generated from E2 amino acid sequences, it was discovered that the alpha-papillomavirus genera segregates into two distinct subgroups (α1 and α2). When these subgroups were individually analyzed, it was determined that the subgroup α1 consensus E2BS favored a spacer of AAAA, whereas subgroup α2 favored the opposite orientation of the same spacer; TTTT. This observation suggests that these conserved inverted linkers could have functional importance

Cutaneous Human Papillomaviruses

Human papillomaviruses (HPVs) exist as more than 100 distinct types. Variants of HPVs appear to be common findings while HPV subtypes have been considered rare. New information about subtypes has recently been reported by us. Our characterisation of subtype HPV38b[FA125] and the identification of several HPV isolates representing putative subtypes have considerably extended the knowledge about this taxon. Cutaneous HPVs are frequently found in healthy skin and some types have also been implicated in non-melanoma skin cancer in immunocompetent as well as in immunosuppressed individuals. However, data on whether these infections persist over time is limited. We recently reported that in a cohort of renal transplant recipients and matched healthy controls, 43% (19/44) of the cutaneous HPV infections persisted after 6.3 years. However, we did not detect any significant association between persistent infections and age, sex, immunosuppressive treatment, history of warts, or genus of HPV. The heterogeneity of cutaneous HPVs, especially in the genus Beta-papillomavirus, has been extended through our characterisation of three new types, HPV93, 96, and 107. The prevalence of these three types as well as HPV38 and its subtype HPV38b[FA125] and the recently described HPV92, was analysed in skin lesions and paired healthy skin. All types were only detected in low amounts and in low viral loads. However, the binding ability of the E7 protein of HPV92, 93 and 96 to the tumour suppressor protein Rb suggests a possible role for these types in the development of skin cancer

Papillomavirus E5: the smallest oncoprotein with many functions

Papillomaviruses (PVs) are established agents of human and animal cancers. They infect cutaneous and mucous epithelia. High Risk (HR) Human PVs (HPVs) are consistently associated with cancer of the uterine cervix, but are also involved in the etiopathogenesis of other cancer types. The early oncoproteins of PVs: E5, E6 and E7 are known to contribute to tumour progression. While the oncogenic activities of E6 and E7 are well characterised, the role of E5 is still rather nebulous. The widespread causal association of PVs with cancer makes their study worthwhile not only in humans but also in animal model systems. The Bovine PV (BPV) system has been the most useful animal model in understanding the oncogenic potential of PVs due to the pivotal role of its E5 oncoprotein in cell transformation. This review will highlight the differences between HPV-16 E5 (16E5) and E5 from other PVs, primarily from BPV. It will discuss the targeting of E5 as a possible therapeutic agent

Diversity of Skin Infections

The identification of infectious agents in cancer has been one of the most rewarding endeavors in cancer research. Currently about 20% of the global cancer burden is linked to an infection. A common characteristic of virus-induced cancer is an increased incidence in immunosuppressed patients, presumably because of impaired host control of virus. Yet non-melanoma skin cancer (NMSC), the cancer that increases most among the immunosuppressed, does not have an established link to infection. NMSC, including squamous cell carcinoma (SCC) and basal cell carcinoma, is the most common cancer among Caucasians. Ultraviolet radiation is an established risk factor. Human papillomaviruses (HPVs) have been established as the major cause of cervical cancer. Many NMSCs contain one or several cutaneous types of HPV. Exploration of a possible infectious etiology of NMSC requires an unbiased and comprehensive approach for detection of as many infections as possible in the tumor. We examined NMSCs and other presumably HPV-associated lesions for the presence of unidentified HPV types or other microorganisms, using a combination of multiple displacement amplification (MDA), which amplifies all DNA in a sample without any requirement of prior knowledge of the nucleotide sequence, degenerate “general HPV primers” PCR and high-throughput sequencing. The most common microbial DNA in NMSC was Staphylococcus aureus (S. aureus). We also identified sequences from at least 40 previously not described putative HPV types, of which three novel types (HPV 109, 112 and 114) and an HPV 88 isolate were cloned and completely sequenced. Prevalences and viral loads were investigated in skin and genital samples from different patient groups. S. aureus DNA was more commonly detected in SCC compared to healthy skin (odds ratio, 6.23; 95% confidence interval, 3.10 – 12.53). However, the study design could not determine the causality of the association. HPV 88, 109 and 112 were almost only found in their index patients, whereas HPV114 was found in 1.7% of the female genital samples. In summary, we find that there is a wide diversity of HPV types in the skin. The association of S. aureus with SCC raises the possibility of general susceptibility to infection in SCC. An association of NMSC with a specific infection remains to be found

Human Papillomaviruses; Epithelial Tropisms, and the Development of Neoplasia.

Papillomaviruses have evolved over many millions of years to propagate themselves at specific epithelial niches in a range of different host species. This has led to the great diversity of papillomaviruses that now exist, and to the appearance of distinct strategies for epithelial persistence. Many papillomaviruses minimise the risk of immune clearance by causing chronic asymptomatic infections, accompanied by long-term virion-production with only limited viral gene expression. Such lesions are typical of those caused by Beta HPV types in the general population, with viral activity being suppressed by host immunity. A second strategy requires the evolution of sophisticated immune evasion mechanisms, and allows some HPV types to cause prominent and persistent papillomas, even in immune competent individuals. Some Alphapapillomavirus types have evolved this strategy, including those that cause genital warts in young adults or common warts in children. These strategies reflect broad differences in virus protein function as well as differences in patterns of viral gene expression, with genotype-specific associations underlying the recent introduction of DNA testing, and also the introduction of vaccines to protect against cervical cancer. Interestingly, it appears that cellular environment and the site of infection affect viral pathogenicity by modulating viral gene expression. With the high-risk HPV gene products, changes in E6 and E7 expression are thought to account for the development of neoplasias at the endocervix, the anal and cervical transformation zones, and the tonsilar crypts and other oropharyngeal sites. A detailed analysis of site-specific patterns of gene expression and gene function is now prompted.The Human Papillomavirus Research Group at the University of Cambridge is funded by the UK Medical Research Council.This is the final version of the article. It first appeared from MDPI via http://dx.doi.org/10.3390/v707280

The human papillomaviruses (HPVs) and HPV DNA testing

The fact that some viruses act as carcinogens has long since been known. Amongst these viruses are some genotypes of the Human Papillomaviruses (HPVs). HPV is most frequently associated with cervical cancer, that is, cancer of the cervix or neck of the uterus. In fact, 95-100% of all cervical cancers are caused by infection with HPV. HPV also causes a high proportion of other anogenital cancers. In 1995, the International Agency for Research on Cancer (IARC) concluded that HPV types 16 and 18 are carcinogenic to humans; HPV types 31 and 33 are probably carcinogenic to humans whilst some HPV types other than 16, 18, 31 and 33 are possibly carcinogenic to humans. This review focuses first on the structure, classification and genome of these particular viruses. Particular attention is given to those features that play a role in the carcinogenicity of particular HPV genotypes. Given the close association between HPV and cervical cancer, detecting the presence of HPV in a particular patient and more specifically, the presence of particular genotypes of HPV, may give an indication of the likelihood of progression to precancerous and cancerous changes in the cervix. In fact, there is much evidence that screening of women with both cytology and HPV DNA tests increases sensitivity for detection of Cervical Intraepithelial Neoplasia (CIN) 3 or cancer sufficiently to permit longer screening intervals than with cytology alone. However, it is important to realize that the presence of HPV does not mean that a woman has or will develop cervical disease. Thus, there is still a dilemma as regards the real utility of HPV DNA testing. Screening and diagnostic procedures for cervical cancer will be discussed in the second part of this review, with special emphasis on HPV DNA testing. The benefits of HPV DNA testing in specific situations will be highlighted, particularly in the case of a diagnosis of Atypical Squamous Cell of Undetermined Significance (ASCUS).peer-reviewe

Factors associated with pregnancy and STI among Aboriginal students in British Columbia.

BACKGROUND: Aboriginal adolescents are more likely to become pregnant and contract an STI than other Canadian adolescents. This study provides some of the first data on factors associated with these outcomes among Aboriginal adolescents. METHODS: A secondary analysis was conducted using 2003 data from a large cross-sectional survey of British Columbia secondary school students. 445 young women and 360 young men who identified as Aboriginal and reported ever having sex were included in analyses. Associations between self-reported pregnancy and STI and 11 exposure variables were examined using logistic regression. RESULTS: Of young women, 10.6% reported a pregnancy; 10.5% of young men reported causing a pregnancy. An STI diagnosis was reported by 4.2% of young women and 3.9% of young men. In multivariate analyses for young men, ever having been sexually abused was the strongest consistent risk factor for causing a pregnancy (AOR = 4.30, 95% CI 1.64-11.25) and STI diagnosis (AOR = 5.58, 95% CI 1.61-19.37). For young women, abuse was associated with increased odds of pregnancy (AOR = 10.37, 95% CI 4.04-26.60) but not STI. Among young women, substance use was the strongest consistent risk factor for both pregnancy (AOR = 3.36, 95% CI 1.25-9.08) and STI (AOR = 5.27, 95% CI 1.50-18.42); for young men, substance use was associated with higher odds of STI (AOR = 4.60, 95% CI 1.11-19.14). Factors associated with decreased risk included community, school and family involvement. CONCLUSIONS: Health care professionals, communities and policy-makers must urgently address sexual abuse and substance use. Exploring promotion of school and community involvement and family cohesion may be useful for sexual health interventions with Aboriginal students