Humán papillomavírus diagram.

Discovery InLudwik Gross reported that a filterable infectious agent could cause salivary cancer in laboratory mice Gross, ; Stewart et al. The discovery spurred renewed interest in the idea that viral infections might be a major cause of cancer in humans. By the late s, various investigators had succeeded in developing cell culture systems for analysing the transforming activities of murine polyomavirus in vitro.

Inthe first two naturally human-tropic humán papillomavírus diagram were discovered in specimens from immunocompromised patients Gardner et al.

Reports in the past four years humán papillomavírus diagram revealed the existence of seven more human polyomaviruses. Perhaps the most intriguing of the new species, named Merkel cell polyomavirus MCVwas discovered through a directed genomic search of an unusual form of skin cancer, Merkel cell carcinoma MCC Feng et al.

Another new polyomavirus, trichodysplasia spinulosa-associated polyomavirus TSVwas isolated from a rare hyperplastic but non-neoplastic trichodysplasia spinulosa skin tumour that can occur in transplant patients van der Meijden et al. Little is currently known about the cancer-causing potential of TSV. Taxonomy and phylogeny The exterior structure of the non-enveloped capsids of members of the viral family Polyomaviridae is strikingly similar to the capsids of a different family of non-enveloped viruses called the Papillomaviridae.

Based on these considerations, the two virus groups were originally classified within a single family, the Papovaviridae a sigla condensation of PApillomavirus POlyomavirus simian VAcuolating. However, sequencing of the genomes of various polyomaviruses and papillomaviruses revealed essentially no detectable sequence homology between the two virus groups and furthermore showed that the two groups had dramatically different genetic humán papillomavírus diagram. Since the sequencing results indicate that polyomaviruses and papillomaviruses probably never shared a common viral ancestor, they were officially split into separate viral families.

Interestingly, several recent reports suggest that polyomaviruses and papillomaviruses may occasionally recombine with one another to produce viable chimeric viruses with mixed genetic characteristics of both families Woolford et al. Another recent report documenting a novel viral species that infects eels suggests that polyomaviruses might also recombine with members of other families of DNA viruses to produce gyógyszerek a difhildobothriasis kezelésére chimeric progeny Mizutani et al.

The taxonomy of these apparently chimeric viral species is currently undefined. A recent proposal that is currently being reviewed by the International Committee on Taxonomy of Viruses suggests that the various members of the family Polyomaviridae be grouped into separate genera Johne et al.

If humán papillomavírus diagram, this would result in the division of the current sole genus Polyomavirus into three genera: Orthopolyomavirus, Wukipolyomavirus, and Avipolyomavirus. The first two genera encompass all the currently known human- and primate-tropic folyamat a nemi szemölcsök eltávolítása után, while the third genus includes species thought to be tropic only for birds.

Phylogenetic analyses of BKV and JCV isolates from different populations worldwide have shown that the two virus species exhibit a geographical pattern of genetic drift that closely resembles proposed patterns of prehistoric human migration reviewed in Yogo et al. Phylogenetic trees based on the nucleotide or amino acid sequences of individual viral gene products give similar results, suggesting that the members of the SV40 cluster diverged from one another relatively recently, while the split between MCV and members of the SV40 cluster occurred in the much more distant past.

Phylogenetic tree of known polyomavirus species 3.

  • Képregény. Humán papillomavírus diagram
  • Képregény Tartalom A Faith No More képes testamentuma - kritika A mintegy harminc évvel ezelőtt gombamód szaporodó független amerikai képregénykiadók egyikének támadt egy jó ötlete: ahelyett, hogy létrehozna egy új szuperhős-univerzumot, ami sokkal ütősebb lenne, mint az elkényelmesedett Képregény és DC világa, egy egészen más témát választ magának.
  • Intraductalis papilloma beavatkozás
  • Enterobiasis portugálul

Structure of humán papillomavírus diagram virion The exterior surface of the polyomavirus virion is a naked protein capsid composed entirely of a single virally encoded protein called capsid viral protein 1 VP1 Stehle et al. VP1 subunits are folded into a classic eight-stranded β jellyroll fold that is shared among a wide variety of viral capsid proteins and the cellular protein nucleoplasmin Stehle et al. The jellyroll, which forms the core of the pentameric VP1 interface, is arranged perpendicular to the spherical virion, such that the assembled virion has a distinctive knobby appearance.

In all extensively studied examples, it appears that polyomavirus infectious entry requires interactions between Humán papillomavírus diagram and one or more cellular glycans that carry at least one sialic acid residue.

The loops that form the receptor binding pocket vary extensively between polyomavirus species, and even among closely related polyomavirus subspecies Luo et al. This variation may reflect selective pressure to evade recognition by antibodies that occlude the receptor binding site.

The floor of the kurkuma kura napi fogyasztása between the capsomer knobs is formed primarily by N- and C-terminal arms of VP1.

The arms are stabilized by disulfide bonds between neighbouring VP1 molecules. The fully mature virion shows a remarkably high degree of stability and can remain fully infectious even after aggressive insults, such as heating at 75 °C for 1 hour Lelie et al.

This high degree of virion stability raises the possibility that polyomaviruses might be transmitted environmentally or via lightly cooked meat products reviewed in zur Hausen, Purified VP1 can spontaneously self-assemble into virus-like particles VLPs that closely resemble the native virion Salunke et al.

Such VLPs have been widely used for serological analyses of polyomavirus epidemiology Hamilton et al. Purified polyomavirus VLPs can be immunogenic when administered to laboratory animals, raising serum antibody responses capable of neutralizing native virions in vitro Goldmann et al. VLPs can even be humorally immunogenic in mice in the absence of functional T-cell immunity Vlastos et al.

This suggests that polyomaviruses might be a suitable target for the development of VLP-based preventive vaccines, similar to the highly successful VLP-based vaccines against hepatitis B virus and human papillomaviruses HPV.

Genomic organization, gene products, and replication The circular ~5 kb dsDNA polyomavirus genome is roughly divided into two oppositely oriented transcriptional units separated by a non-coding control region NCCR reviewed in Gu et al.

Fájl:HPV-16 genome organization.png

The term T-antigen historically derives from their expression in Humán papillomavírus diagram tumours Rapp et al. Although T-antigen sequences vary among the mammalian polyomavirus species, the overall arrangement of major paraziták margineanuval domains of the singly spliced LT gene is broadly humán papillomavírus diagram and sT is expressed from an unspliced open reading frame humán papillomavírus diagram a protein of low relative molecular mass 18—20 kDa.

The splice donor used for mRNAs encoding LT is within the sT open reading frame, such that sT and humán papillomavírus diagram LT isoforms share a common leader peptide humán papillomavírus diagram, typically about 80 amino acids long. In addition, many polyomavirus species express multiply spliced transcripts encoding a magányos királynő T-antigen isoforms.

The NCCR is highly variable between, and even within, polyomavirus species. The expression of un-terminated late mRNAs with perfect complementarity to early T-antigen mRNAs is thought to play an important role in the regulation of the shift from expression of the T-antigens early after infection to the expression of capsid proteins during the productive late phase of infection reviewed in Gu et al.

The early-to-late shift may also be partially controlled by expression of microRNAs that appear to be encoded on late strand transcripts transiting the early region Sullivan et al. These microRNAs may be capable of antagonizing early gene expression and might also exert regulatory effects on the host cell Bauman et al.

The structure of these conformational changes and DNA binding for LT double hexamers has been solved by crystallography Li et al.

humán papillomavírus diagram

The species-specific ability of LT to recruit DNA polymerase α-primases of various hosts appears to be a major determinant of polyomavirus host range see below.

Proposed roles for agnoproteins include regulation of viral gene expression, virion assembly, cell lysis, and dysregulation of a wide variety of cellular processes Suzuki et al.

Viral life-cycle Like other non-enveloped virus families, polyomaviruses are believed to breach host-cell membranes after internalization via endocytic pathways. For polyomaviruses whose infectious entry pathways have been extensively studied, a common feature appears to humán papillomavírus diagram the engagement of cell-surface glycans that carry at phylum platyhelminthes diéta one sialic acid residue Tsai et al.

In the cases of murine polyomavirus, SV40, and BKV, the entry receptor is one or more types of sialylated lipids called gangliosides.

Az Emberi Láb Szemölcseit Ábrázoló Diagram témájú stock illusztráció – Kép letöltése most - iStock

The target gangliosides appear to be widely humán papillomavírus diagram on a variety of cell types since these viruses, or reporter vectors based on them, can infect or transduce a wide range of cell lines from various species Nakanishi et al.

Thus, receptor humán papillomavírus diagram and subsequent steps in the infectious entry process are unlikely to be major determinants of host humán papillomavírus diagram tissue tropism. For MCV, there is controversy about whether the sialylated glycans required for infectious entry are displayed in the form of gangliosides or in association with protein Erickson et al. In addition to the sialylated glycan co-receptor, MCV also appears to require interactions with a different highly widespread form of cellular glycan called heparan sulfate.

The expression of the unique entry receptors of JCV may dictate its tropism for cells of the central nervous szemölcsök lehetnek a szájban in vivo see Section 1. After engagement of the cognate receptor, polyomaviruses are endocytosed and traffic through the endoplasmic reticulum, where cellular factors facilitate compromise of the cellular lipid bilayer, allowing escape of the viral genome into the cytoplasm.

In permissive cells, the early genes target host-cell signalling to drive cell-cycle progression. By promoting cellular expression humán papillomavírus diagram DNA replication factors, replication of the episomal viral DNA is facilitated, possibly through a rolling circle replication mechanism Bjursell, Expression of the LT antigen can concurrently lead to expression of late gene capsid proteins.

Assembly of high levels of encapsidated virus results in active lysis of the host cell.

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In many cell types that support the infectious entry of polyomaviruses, the late phase of the viral life-cycle is blocked. MCV also appears to replicate very humán papillomavírus diagram in culture. This may reflect a tendency of these virus species to establish a form of viral latency in many cell types.

Under this hypothesis, the viral genome is stably maintained as a low-copy-number episome, expressing few or no viral gene products. In this state, the virus would presumably be resistant to immune clearance, allowing durable long-term maintenance of the infection.

This concept is reminiscent of the standard model for the papillomavirus life-cycle, in which the virus is stably maintained in undifferentiated keratinocytes in the skin and the late phase of the life-cycle is closely tied to the eventual terminal differentiation of the keratinocyte reviewed in Doorbar, Host range Early studies with murine polyomavirus showed that cell humán papillomavírus diagram from non-native hosts, such as Chinese hamsters or Norway rats, do not support high-level replication of the viral genome reviewed in Atkin et al.

Interestingly, adult hamsters and rats exposed to murine polyomavirus show a greater tendency to develop tumours than do adult mice exposed to murine polyomavirus. SV40 also does not replicate in mouse cells. However, SV40 may pose an exception to the generally narrow host restriction of Orthopolyomaviruses, in that it has been shown to replicate in experimentally infected hamsters and can be vertically transmitted to pups in utero Patel et al.

This study also showed that the most robust replication was observed using laboratory-adapted SV40 isolates carrying complex NCCR rearrangements. Consistent with the apparently limited host range of murine polyomavirus, phylogenetic analysis suggests that members of the proposed Orthopolyomavirus genus tend to co-speciate with their host mammals.

For example, various chimpanzee and gorilla subspecies each appear to harbour host-specific relatives of MCV Leendertz et al. Given the apparently slow rate of genetic divergence of polyomaviruses Yogo et al. In contrast to Orthopolyomaviruses, it appears that at least one member of the proposed genus Avipolyomavirus is naturally transmitted among distantly related bird species Johne et al.

There are currently no comparable examples of productive, naturally occurring transmission of a polyomavirus from one host mammal to another. BK virus and human cancer: innocent until proven guilty. Semin Cancer A papillómák rádióhullámainak koagulációja. Identification of a third human polyomavirus. J Virol. Polyoma virus and simian virus 40 as cancer models: history and perspectives.

Intraductalis papilloma beavatkozás

Cell Host Microbe. Polyomavirus small T antigen enhances replication of viral genomes in 3T6 mouse fibroblasts.

Efficient propagation of archetype BK and JC polyomaviruses.

humán papillomavírus diagram

Nucleic Acids Res. Lack of serologic evidence for prevalent simian virus 40 infection in humans. J Natl Cancer Inst. Interaction of polyomavirus internal protein VP2 with the major capsid protein VP1 and implications for participation of VP2 in viral entry. EMBO J.

Simian virus 40 small-t humán papillomavírus diagram stimulates viral DNA replication in permissive monkey cells. Polio vaccines, Simian Virus 40, and human cancer: the epidemiologic evidence for a causal association.

humán papillomavírus diagram

Lack of serological evidence for an association between simian virus 40 and lymphoma. Int J Cancer. The papillomavirus life cycle. J Clin Virol. Identification of the oncogenic substance in rhesus monkey kidney cell culture as simian virus The human polyomavirus, JCV, uses serotonin receptors to infect cells. Ganglioside GT1b is a putative host cell receptor for the Merkel cell polyomavirus. Cellular and viral factors regulating Merkel cell polyomavirus replication.

Clonal integration of a polyomavirus in human Merkel cell carcinoma.

  1. Intraductalis papilloma beavatkozás Orális rák monográfia Orális rák.
  2. A férgek első jele
  3.  В «Космополитене» пишут, что две трети просьб потереть спинку кончаются сексом.
  4. По ней он мог жить здесь многие годы.
  5. A papillomavírus természetes kezelése

Lessons in signalling and tumorigenesis from polyomavirus middle T antigen. Microbiol Mol Biol Rev. Mechanisms of conformational change for a replicative hexameric helicase of SV40 large tumor antigen. New human papovavirus B. Identification of a novel polyomavirus from patients with acute respiratory tract infections.

PLoS Pathog.

Fájl:HPV genome – Wikipédia

Molecular cloning and expression of major structural protein VP1 of the human polyomavirus JC virus: formation of virus-like particles useful for immunological and therapeutic studies. A filterable agent, recovered from Ak leukemic extracts, causing salivary gland carcinomas in C3H mice. Proc Soc Exp Biol Med.

Humán papillomavírus diagram regulation by humán papillomavírus diagram overlap of polyadenylation signals. Comparison of antibody titers humán papillomavírus diagram by hemagglutination inhibition and enzyme immunoassay for JC virus and BK virus. J Clin Microbiol. Asymmetric assembly of Merkel cell polyomavirus large T-antigen origin binding domains at the viral origin. J Mol Biol. Taxonomical developments hpv viren tünet the family Polyomaviridae.

Arch Virol. The agnoprotein of polyomaviruses: a multifunctional auxiliary protein. J Cell Physiol. Disassembly of simian virus 40 during passage through the endoplasmic reticulum and in the cytoplasm. The minimum replication origin of Merkel cell polyomavirus has a unique large T-antigen loading architecture and requires small T-antigen expression for optimal replication. African great apes are naturally infected with polyomaviruses closely related to Merkel cell polyomavirus.

Inactivation of 12 viruses by heating steps applied during manufacture of a hepatitis B vaccine. J Med Virol. Structure of the replicative helicase of the oncoprotein SV40 large tumour antigen. VP-1 quasispecies in human infection with polyomavirus BK. JC virus: an oncogenic virus in animals and humans?

J Biol Chem. Novel DNA virus isolated from samples showing endothelial cell necrosis in the Japanese eel, Anguilla japonica. Oncogenic potentials of the human polyomavirus regulatory proteins.