|Micrograph showing a polyomavirus infected cell—large (blue) cell below-center-left. Urine cytology specimen.|
|Group:||Group I (dsDNA)|
Polyomaviridae is a family of viruses whose natural hosts are primarily mammals and birds. As of the most recent (2015) taxonomy release by the International Committee on Taxonomy of Viruses, there were 73 recognized species in this family contained within four genera, as well as three species that could not be assigned to a genus. Of these, 13 species are known to infect humans. Most of these viruses, such as BK virus and JC virus, are very common and typically asymptomatic in most human populations studied. However, some polyomaviruses are associated with human disease, particularly in immunocompromised individuals; BK virus is associated with nephropathy in renal transplant and non-renal solid organ transplant patients, JC virus with progressive multifocal leukoencephalopathy, and Merkel cell virus with Merkel cell cancer.
Some members of the family are oncoviruses, meaning they can cause tumors; they often persist as latent infections in a host without causing disease, but may produce tumors in a host of a different species, or in individuals with ineffective immune systems. The family was first discovered due to its oncogenic properties; some members of the family, most prominently murine polyomavirus, have been extensively studied in the laboratory to understand the mechanism by which they induce carcinogenesis. The name polyoma refers to the viruses' ability to produce multiple (poly-) tumors (-oma).
Structure and genome
Polyomaviruses are unenveloped double-stranded DNA viruses with circular genomes of around 5000 base pairs. The genome is packaged in a viral capsid of about 40-50 nanometers in diameter, which is icosahedral in shape (T=7 symmetry). The capsid is composed of 72 pentameric capsomeres of a protein called VP1, which is capable of self-assembly into a closed icosahedron; each pentamer of VP1 is associated with one molecule of one of the other two capsid proteins, VP2 or VP3.
The genome of a typical polyomavirus codes for between 5 and 9 proteins, divided into two transcriptional regions called the early and late regions due to the time during infection in which they are transcribed. Each region is transcribed by the host cell's RNA polymerase II as a single pre-messenger RNA containing multiple genes. The early region usually codes for two proteins, the small and large tumor antigens, produced by alternative splicing. The late region contains the three capsid structural proteins VP1, VP2, and VP3, produced by alternative translational start sites. Additional genes and other variations on this theme are present in some viruses: for example, rodent polyomaviruses have a third protein called middle tumor antigen in the early region, which is extremely efficient at inducing cellular transformation; SV40 has an additional capsid protein VP4; some examples have an additional regulatory protein called agnoprotein expressed from the late region. The genome also contains a non-coding control or regulatory region containing the early and late regions' promoters, transcriptional start sites, and the origin of replication.
|Genus||Structure||Symmetry||Capsid||Genomic arrangement||Genomic segmentation|
Replication and life cycle
The polyomavirus life cycle begins with entry into a host cell. Cellular receptors for polyomaviruses are sialic acid residues of glycans, commonly gangliosides. The attachment of polyomaviruses to host cells is mediated by the binding of VP1 to sialylated glycans on the cell surface. In some particular viruses, additional cell-surface interactions occur; for example, the JC virus is believed to require interaction with the 5HT2A receptor and the Merkel cell virus with heparan sulfate. However, in general virus-cell interactions are mediated by commonly occurring molecules on the cell surface, and therefore are likely not a major contributor to individual viruses' observed cell-type tropism. After binding to molecules on the cell surface, the virion is endocytosed and enters the endoplasmic reticulum - a behavior unique among known non-enveloped viruses - where the viral capsid structure is likely to be disrupted by action of host cell disulfide isomerase enzymes.
The details of transit to the nucleus are not clear and may vary among individual polyomaviruses. It has been frequently reported that an intact, albeit distorted, virion particle is released from the endoplasmic reticulum into the cell cytoplasm, where the genome is released from the capsid, possibly due to the low calcium concentration in the cytoplasm. Both expression of viral genes and replication of the viral genome occur in the nucleus using host cell machinery. The early genes - comprising at minimum the small tumor antigen (ST) and large tumor antigen (LT) - are expressed first, from a single alternatively spliced messenger RNA strand. These proteins serve to manipulate the host's cell cycle - dysregulating the transition from G1 phase to S phase, when the host cell's genome is replicated - because host cell DNA replication machinery is needed for viral genome replication. The precise mechanism of this dysregulation depends on the virus; for example, SV40 LT can directly bind host cell p53, but murine polyomavirus LT does not. LT induces DNA replication from the viral genome's non-coding control region (NCCR), after which expression of the early mRNA is reduced and expression of the late mRNA, which encodes the viral capsid proteins, begins. Several mechanisms have been described for regulating the transition from early to late gene expression, including the involvement of the LT protein in repressing the early promoter, the expression of un-terminated late mRNAs with extensions complementary to early mRNA, and the expression of regulatory microRNA.
Expression of the late genes results in accumulation of the viral capsid proteins in the host cell cytoplasm. Capsid components enter the nucleus in order to encapsidate new viral genomic DNA. New virions may be assembled in viral factories. The mechanism of viral release from the host cell varies among polyomaviruses; some express proteins that facilitate cell exit, such as the agnoprotein or VP4. In some cases high levels of encapsidated virus result in cell lysis, releasing the virions.
|Genus||Host details||Tissue tropism||Entry details||Release details||Replication site||Assembly site||Transmission|
|Polyomavirus||Mammals; birds||Respiratory system; kidneys, brain||Cell receptor endocytosis||Lysis||Nucleus||Nucleus||Oral-fecal|
The large tumor antigen plays a key role in regulating the viral life cycle by binding to the viral origin of DNA replication where it promotes DNA synthesis. Also as the polyomavirus relies on the host cell machinery to replicate the host cell needs to be in s-phase for this to begin. Due to this, large T-antigen also modulates cellular signaling pathways to stimulate progression of the cell cycle by binding to a number of cellular control proteins. This is achieved by a two prong attack of inhibiting tumor suppressing genes p53 and members of the retinoblastoma (pRB) family, and stimulating cell growth pathways by binding cellular DNA, ATPase-helicase, DNA polymerase α association, and binding of transcription preinitiation complex factors. This abnormal stimulation of the cell cycle is a powerful force for oncogenic transformation.
The small tumor antigen protein is also able to activate several cellular pathways that stimulate cell proliferation. Polyomavirus small T antigens commonly target protein phosphatase 2A (PP2A), a key multisubunit regulator of multiple pathways including Akt, the mitogen-activated protein kinase (MAPK) pathway, and the stress-activated protein kinase (SAPK) pathway. Merkel cell polyomavirus small T antigen encodes a unique domain, called the LT-stabilization domain (LSD), that binds to and inhibits the FBXW7 E3 ligase regulating both cellular and viral oncoproteins. Unlike for SV40, the MCV small T antigen directly transforms rodent cells in vitro.
The middle tumor antigen is used in model organisms developed to study cancer, such as the MMTV-PyMT system where middle T is coupled to the MMTV promoter. There it functions as an oncogene, while the tissue where the tumor develops is determined by the MMTV promoter.
The polyomavirus capsid consists of one major component, major capsid protein VP1, and one or two minor components, minor capsid proteins VP2 and VP3. VP1 pentamers form the closed icosahedral viral capsid, and in the interior of the capsid each pentamer is associated with one molecule of either VP2 or VP3. Some polyomaviruses, such as Merkel cell polyomavirus, do not encode or express VP3. The capsid proteins are expressed from the late region of the genome.
The agnoprotein is a small multifunctional phospho-protein found in the late coding part of the genome of some polyomaviruses, most notably BK virus, JC virus, and SV40. It is essential for proliferation in the viruses that express it and is thought to be involved in regulating the viral life cycle, particularly replication and viral exit from the host cell, but the exact mechanisms are unclear.
The polyomaviruses are members of group I (dsDNA viruses). The classification of Polyomaviruses has been the subject of several proposed revisions as new members of the group are discovered. Formerly, polyomaviruses and papillomaviruses, which share many structural features but have very different genomic organizations, were classified together in the now-obsolete family Papovaviridae. (The name Papovaviridae derived from three abbreviations: Pa for Papillomavirus, Po for Polyomavirus, and Va for "vacuolating.") The polyomaviruses were divided into three major clades (that is, genetically-related groups): the SV40 clade, the avian clade, and the murine polyomavirus clade. A subsequent proposed reclassification by the International Committee on Taxonomy of Viruses (ICTV) recommended dividing the family of Polyomaviridae into three genera:
- Genus Orthopolyomavirus (type species SV40)
- Genus Wukipolyomavirus (type species KI polyomavirus)
- Genus Avipolyomavirus (type species Avian polyomavirus)
The current ICTV classification system recognises four genera and 76 species, of which three could not be assigned a genus. This system retains the distinction between avian and mammalian viruses, grouping the avian subset into the genus Gammapolyomavirus.
- Genus Alphapolyomavirus, type species Mus musculus polyomavirus 1 (murine polyomavirus)
- Genus Betapolyomavirus, type species Macaca mulatta polyomavirus 1 (SV40)
- Genus Gammapolyomavirus, type species Aves polyomavirus 1
- Genus Deltapolyomavirus, type species Human polyomavirus 6
Most polyomaviruses do not infect humans. Of the polyomaviruses cataloged as of 2016, a total of 13 were known with human hosts. Many human polyomaviruses are very common and are asymptomatic. However, some polyomaviruses are associated with human disease, particularly in immunocompromised individuals. MCV is highly divergent from the other human polyomaviruses and is most closely related to murine polyomavirus. Trichodysplasia spinulosa-associated polyomavirus (TSV) is distantly related to MCV. Two viruses—HPyV6 and HPyV7—are most closely related to KI and WU viruses, while HPyV9 is most closely related to the African green monkey-derived lymphotropic polyomavirus (LPV).
A fourteenths virus has been desciribed. Lyon IARC polyoma virus is related to raccoon polyoma virus.
List of human polyomaviruses
|Species||Proposed genus||Virus name||Abbreviation||NCBI RefSeq||Year of discovery||Clinical correlate (if any)||References|
|Human polyomavirus 5||Alpha||Merkel cell polyomavirus||MCPyV||NC_010277||2008||Merkel cell cancer|||
|Human polyomavirus 8||Alpha||Trichodysplasia spinulosa polyomavirus||TSPyV||NC_014361||2010||Trichodysplasia spinulosa|||
|Human polyomavirus 9||Alpha||Human polyomavirus 9||HPyV9||NC_015150||2011||None known|||
|Human polyomavirus 12||Alpha||Human polyomavirus 12||HPyV12||NC_020890||2013||None known|||
|Human polyomavirus 13||Alpha||New Jersey polyomavirus||NJPyV||NC_024118||2014||None known|||
|Human polyomavirus 1||Beta||BK polyomavirus||BKPyV||NC_001538||1971||Polyomavirus-associated nephropathy; haemorrhagic cystitis|||
|Human polyomavirus 2||Beta||JC polyomavirus||JCPyV||NC_001699||1971||Progressive multifocal leukoencephalopathy|||
|Human polyomavirus 3||Beta||KI polyomavirus||KIPyV||NC_009238||2007||None known|||
|Human polyomavirus 4||Beta||WU polyomavirus||WUPyV||NC_009539||2007||None known|||
|Human polyomavirus 6||Delta||Human polyomavirus 6||HPyV6||NC_014406||2010||HPyV6 associated pruritic and dyskeratotic dermatitis|||
|Human polyomavirus 7||Delta||Human polyomavirus 7||HPyV7||NC_014407||2010||HPyV7-related epithelial hyperplasia|||
|Human polyomavirus 10||Delta||MW polyomavirus||MWPyV||NC_018102||2012||None known|||
|Human polyomavirus 11||Delta||STL polyomavirus||STLPyV||NC_020106||2013||None known|||
The proposed Deltapolyomavirus genus contains only the four human viruses shown, with human polyomavirus 6 as the type species. The Alpha and Beta groups contain viruses that infect a variety of mammals. The Gamma group contains the avian viruses. Clinically significant disease associations are shown only where causality is expected.
Antibodies to the monkey lymphotropic polyomavirus have been detected in humans suggesting that this virus - or a closely related virus - can infect humans.
All the polyomaviruses are highly common childhood and young adult infections. Most of these infections appear to cause little or no symptoms. These viruses are probably lifelong persistent among almost all adults. Diseases caused by human polyomavirus infections are most common among immunocompromised people; disease associations include BK virus with nephropathy in renal transplant and non-renal solid organ transplant patients, JC virus with progressive multifocal leukoencephalopathy, and Merkel cell virus (MCV) with Merkel cell cancer.
SV40 replicates in the kidneys of monkeys without causing disease, but can cause cancer in rodents under laboratory conditions. In the 1950s and early 1960s, well over 100 million people may have been exposed to SV40 due to previously undetected SV40 contamination of polio vaccine, prompting concern about the possibility that the virus might cause disease in humans. Although it has been reported as present in some human cancers, including brain tumors, bone tumors, mesotheliomas, and non-Hodgkin's lymphomas, accurate detection is often confounded by high levels of cross-reactivity for SV40 with widespread human polyomaviruses. Most virologists dismiss SV40 as a cause for human cancers.
The diagnosis of polyomavirus almost always occurs after the primary infection as it is either asymptomatic or sub-clinical. Antibody assays are commonly used to detect presence of antibodies against individual viruses. Competition assays are frequently needed to distinguish among highly similar polyomaviruses.
In cases of progressive multifocal leucoencephalopathy (PML), a cross-reactive antibody to SV40 T antigen (commonly Pab419) is used to stain tissues directly for the presence of JC virus T antigen. PCR can be used on a biopsy of the tissue or cerebrospinal fluid to amplify the polyomavirus DNA. This allows not only the detection of polyomavirus but also which sub type it is.
There are three main diagnostic techniques used for the diagnosis of the reactivation of polyomavirus in polyomavirus nephropathy (PVN): urine cytology, quantification of the viral load in both urine and blood, and a renal biopsy. The reactivation of polyomavirus in the kidneys and urinary tract causes the shedding of infected cells, virions, and/or viral proteins in the urine. This allows urine cytology to examine these cells, which if there is polyomavirus inclusion of the nucleus, is diagnostic of infection. Also as the urine of an infected individual will contain virions and/or viral DNA, quanitation of the viral load can be done through PCR. This is also true for the blood.
Renal biopsy can also be used if the two methods just described are inconclusive or if the specific viral load for the renal tissue is desired. Similarly to the urine cytology, the renal cells are examined under light microscopy for polyomavirus inclusion of the nucleus, as well as cell lysis and viral partials in the extra cellular fluid. The viral load as before is also measure by PCR.
Tissue staining using a monoclonal antibody against MCV T antigen shows utility in differentiating Merkel cell carcinoma from other small, round cell tumors. Blood tests to detect MCV antibodies have been developed and show that infection with the virus is widespread although Merkel cell carcinoma patients have exceptionally higher antibody responses than asymptomatically infected persons.
Murine polyomavirus was the first polyomavirus discovered, having been reported by Ludwik Gross in 1953 as an extract of mouse leukemias capable of inducing parotid gland tumors. The causative agent was identified as a virus by Sarah Stewart and Bernice Eddy, after whom it was once called "SE polyoma". The term "polyoma" refers to the viruses' ability to produce multiple (poly-) tumors (-oma) under certain conditions. The name has been criticized as a "meatless linguistic sandwich" ("meatless" because both morphemes in "polyoma" are affixes) giving little insight into the viruses' biology; in fact, subsequent research has found that most polyomaviruses rarely cause clinically significant disease in their host organisms under natural conditions.
Dozens of polyomaviruses have been identified and sequenced as of 2016, infecting mainly birds and mammals. Two polyomaviruses are known to infect fish, the black sea bass and gilthead seabream. A total of thirteen polyomaviruses are known to infect humans.
- ICTV. "Virus Taxonomy: 2015 Release". Retrieved 26 July 2016.
- Polyomaviridae Study Group of the International Committee on Taxonomy of, Viruses; Calvignac-Spencer, S; Feltkamp, MC; Daugherty, MD; Moens, U; Ramqvist, T; Johne, R; Ehlers, B (29 February 2016). "A taxonomy update for the family Polyomaviridae.". Archives of Virology. 161: 1739–50. PMID 26923930. doi:10.1007/s00705-016-2794-y.
- DeCaprio, JA; Garcea, RL (2013). "A cornucopia of human polyomaviruses". Nat. Rev. Microbiol. 11: 264–76. PMC . PMID 23474680. doi:10.1038/nrmicro2992.
- Gossai, A; Waterboer, T; Nelson, HH; Michel, A; Willhauck-Fleckenstein, M; Farzan, SF; Hoen, AG; Christensen, BC; Kelsey, KT; Marsit, CJ; Pawlita, M; Karagas, MR (1 January 2016). "Seroepidemiology of Human Polyomaviruses in a US Population.". American Journal of Epidemiology. 183 (1): 61–9. PMID 26667254. doi:10.1093/aje/kwv155.
- Kean, JM; Rao, S; Wang, M; Garcea, RL (March 2009). "Seroepidemiology of human polyomaviruses.". PLOS Pathogens. 5 (3): e1000363. PMC . PMID 19325891. doi:10.1371/journal.ppat.1000363.
- Jamboti, JS (18 January 2016). "BK virus nephropathy in renal transplant recipients.". Nephrology (Carlton, Vic.). 21: 647–54. PMID 26780694. doi:10.1111/nep.12728.
- Kuppachi, S; Kaur, D; Holanda, DG; Thomas, CP (April 2016). "BK polyoma virus infection and renal disease in non-renal solid organ transplantation.". Clinical kidney journal. 9 (2): 310–8. PMC . PMID 26985385. doi:10.1093/ckj/sfv143.
- Adang, L; Berger, J (2015). "Progressive Multifocal Leukoencephalopathy.". F1000Research. 4. PMC . PMID 26918152. doi:10.12688/f1000research.7071.1.
- Feng, H.; Shuda, M.; Chang, Y.; Moore, P. S. (2008). "Clonal Integration of a Polyomavirus in Human Merkel Cell Carcinoma". Science. 319 (5866): 1096–100. PMC . PMID 18202256. doi:10.1126/science.1152586.
- Salunke, DM; Caspar, DL; Garcea, RL (12 September 1986). "Self-assembly of purified polyomavirus capsid protein VP1.". Cell. 46 (6): 895–904. PMID 3019556. doi:10.1016/0092-8674(86)90071-1.
- DeCaprio, JA; Garcea, RL (April 2013). "A cornucopia of human polyomaviruses.". Nature Reviews. Microbiology. 11 (4): 264–76. PMC . PMID 23474680. doi:10.1038/nrmicro2992.
- Gaynor, AM; Nissen, MD; Whiley, DM; Mackay, IM; Lambert, SB; Wu, G; Brennan, DC; Storch, GA; Sloots, TP; Wang, D (4 May 2007). "Identification of a novel polyomavirus from patients with acute respiratory tract infections.". PLOS Pathogens. 3 (5): e64. PMC . PMID 17480120. doi:10.1371/journal.ppat.0030064.
- International Agency for Research on Cancer (2013). "Introduction to Polyomaviruses" (PDF). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. 104: 121–131.
- Buch, MH; Liaci, AM; O'Hara, SD; Garcea, RL; Neu, U; Stehle, T (October 2015). "Structural and Functional Analysis of Murine Polyomavirus Capsid Proteins Establish the Determinants of Ligand Recognition and Pathogenicity.". PLOS Pathogens. 11 (10): e1005104. PMC . PMID 26474293. doi:10.1371/journal.ppat.1005104.
- Inoue, T.; Tsai, B. (2 January 2013). "How Viruses Use the Endoplasmic Reticulum for Entry, Replication, and Assembly". Cold Spring Harbor Perspectives in Biology. 5 (1): a013250. PMC . PMID 23284050. doi:10.1101/cshperspect.a013250.
- Gjoerup, Ole; Chang, Yuan (2010). "Chapter 1 – Update on Human Polyomaviruses and Cancer". Advances in Cancer Research. 106: 1–51. doi:10.1016/S0065-230X(10)06001-X.
- Andrabi, S.; Hwang, J. H.; Choe, J. K.; Roberts, T. M.; Schaffhausen, B. S. (10 August 2011). "Comparisons between Murine Polyomavirus and Simian Virus 40 Show Significant Differences in Small T Antigen Function". Journal of Virology. 85 (20): 10649–58. PMID 20399955. doi:10.1128/JVI.05034-11.
- White, Martyn K.; Gordon, Jennifer; Reiss, Krzysztof; Del Valle, Luis; Croul, Sidney; Giordano, Antonio; Darbinyan, Armine; Khalili, Kamel (2005). "Human polyomaviruses and brain tumors". Brain Research Reviews. 50 (1): 69–85. PMID 15982744. doi:10.1016/j.brainresrev.2005.04.007.
- Kazem, Siamaque; Van Der Meijden, Els; Wang, Richard C.; Rosenberg, Arlene S.; Pope, Elena; Benoit, Taylor; Fleckman, Philip; Feltkamp, Mariet C. W. (2014). "Polyomavirus-Associated Trichodysplasia Spinulosa Involves Hyperproliferation, pRB Phosphorylation and Upregulation of p16 and p21". PLoS ONE. 9 (10): e108947. PMC . PMID 25291363. doi:10.1371/journal.pone.0108947.
- Kelley, W. L.; Georgopoulos, C (1997). "The T/t common exon of simian virus 40, JC, and BK polyomavirus T antigens can functionally replace the J-domain of the Escherichia coli DnaJ molecular chaperone". Proceedings of the National Academy of Sciences of the United States of America. 94 (8): 3679–3684. Bibcode:1997PNAS...94.3679K. PMC . PMID 9108037. doi:10.1073/pnas.94.8.3679.
- Pallas, D. C.; Shahrik, L. K.; Martin, B. L.; Jaspers, S; Miller, T. B.; Brautigan, D. L.; Roberts, T. M. (1990). "Polyoma small and middle T antigens and SV40 small t antigen form stable complexes with protein phosphatase 2A". Cell. 60 (1): 167–76. PMID 2153055. doi:10.1016/0092-8674(90)90726-u.
- Sontag, Estelle; Fedorov, Sergei; Kamibayashi, Craig; Robbins, David; Cobb, Melanie; Mumby, Marc (1993). "The interaction of SV40 small tumor antigen with protein phosphatase 2A stimulates the map kinase pathway and induces cell proliferation". Cell. 75 (5): 887–97. PMID 8252625. doi:10.1016/0092-8674(93)90533-V.
- Watanabe, G; Howe, A; Lee, R. J.; Albanese, C; Shu, I. W.; Karnezis, A. N.; Zon, L; Kyriakis, J; Rundell, K; Pestell, R. G. (1996). "Induction of cyclin D1 by simian virus 40 small tumor antigen". Proceedings of the National Academy of Sciences of the United States of America. 93 (23): 12861–12866. Bibcode:1996PNAS...9312861W. PMC . PMID 8917510. doi:10.1073/pnas.93.23.12861.
- Kwun, Hyun Jin; Shuda, Masahiro; Feng, Huichen; Camacho, Carlos J.; Moore, Patrick S.; Chang, Yuan (2013). "Merkel Cell Polyomavirus Small T Antigen Controls Viral Replication and Oncoprotein Expression by Targeting the Cellular Ubiquitin Ligase SCFFbw7". Cell Host & Microbe. 14 (2): 125–135. PMC . PMID 23954152. doi:10.1016/j.chom.2013.06.008.
- Shuda, Masahiro; Kwun, Hyun Jin; Feng, Huichen; Chang, Yuan; Moore, Patrick S. (2011). "Human Merkel cell polyomavirus small T antigen is an oncoprotein targeting the 4E-BP1 translation regulator". Journal of Clinical Investigation. 121 (9): 3623–34. PMC . PMID 21841310. doi:10.1172/JCI46323.
- Chen, Xiaojiang S.; Stehle, Thilo; Harrison, Stephen C. (1998-06-15). "Interaction of polyomavirus internal protein VP2 with the major capsid protein VP1 and implications for participation of VP2 in viral entry". The EMBO Journal. 17 (12): 3233–3240. ISSN 0261-4189. PMC . PMID 9628860. doi:10.1093/emboj/17.12.3233.
- Schowalter, Rachel M.; Pastrana, Diana V.; Pumphrey, Katherine A.; Moyer, Adam L.; Buck, Christopher B. (2010). "Merkel Cell Polyomavirus and Two Previously Unknown Polyomaviruses Are Chronically Shed from Human Skin". Cell Host & Microbe. 7 (6): 509–15. PMC . PMID 20542254. doi:10.1016/j.chom.2010.05.006.
- Sariyer, Ilker K; Saribas, Abdullah S; White, Martyn K; Safak, Mahmut (2011). "Infection by agnoprotein-negative mutants of polyomavirus JC and SV40 results in the release of virions that are mostly deficient in DNA content". Virology Journal. 8: 255. PMC . PMID 21609431. doi:10.1186/1743-422X-8-255.
- Saribas, AS; Coric, P; Hamazaspyan, A; Davis, W; Axman, R; White, MK; Abou-Gharbia, M; Childers, W; Condra, JH; Bouaziz, S; Safak, M (October 2016). "Emerging From the Unknown: Structural and Functional Features of Agnoprotein of Polyomaviruses.". Journal of cellular physiology. 231 (10): 2115–27. PMID 26831433. doi:10.1002/jcp.25329.
- International Agency for Research on Cancer (2013). "IARC Working Group on the Evaluation of Carcinogenic Risk to Humans. Malaria and Some Polyomaviruses (SV40, BK, JC, and Merkel Cell Viruses).". IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. 104.
- Perez-Losada, M.; Christensen, R. G.; McClellan, D. A.; Adams, B. J.; Viscidi, R. P.; Demma, J. C.; Crandall, K. A. (2006). "Comparing Phylogenetic Codivergence between Polyomaviruses and Their Hosts". Journal of Virology. 80 (12): 5663–9. PMC . PMID 16731904. doi:10.1128/JVI.00056-06.
- Johne, Reimar; Buck, Christopher B.; Allander, Tobias; Atwood, Walter J.; Garcea, Robert L.; Imperiale, Michael J.; Major, Eugene O.; Ramqvist, Torbjorn; Norkin, Leonard C. (2011). "Taxonomical developments in the family Polyomaviridae". Archives of Virology. 156 (9): 1627–34. PMC . PMID 21562881. doi:10.1007/s00705-011-1008-x.
- Siqueira, JD; Ng, T; Miller, M; Li, L; Deng, X; Dodd, E; Batac, F; Delwart, E (2017). "Endemic infection of stranded southern sea otters (Enhydra lutris nereis) with novel parvovirus, polyomavirus, and adenovirus". J Wildl Dis. doi:10.7589/2016-04-082.
- Dela Cruz FN Jr, Li L, Delwart E, Pesavento PA (2017) A novel pulmonary polyomavirus in alpacas (Vicugna pacos). Vet Microbiol 201:49-55. doi: 10.1016/j.vetmic.2017.01.005
- Gheit T, Dutta S, Oliver J, Robitaille A, Hampras S, Combes JD, McKay-Chopin S, Le Calvez-Kelm F, Fenske N, Cherpelis B, Giuliano AR, Franceschi S, McKay J, Rollison DE2, Tommasino M (2017) Isolation and characterization of a novel putative human polyomavirus. Virology 506:45-54. doi: 10.1016/j.virol.2017.03.007
- Altman, Lawreence K. (2008-01-18). "Virus Is Linked to a Powerful Skin Cancer". The New York Times. Retrieved 2008-01-18.
- Feng, H.; Shuda, M.; Chang, Y.; Moore, P. S. (2008). "Clonal Integration of a Polyomavirus in Human Merkel Cell Carcinoma". Science. 319 (5866): 1096–100. Bibcode:2008Sci...319.1096F. PMC . PMID 18202256. doi:10.1126/science.1152586.
- Shuda, Masahiro; Arora, Reety; Kwun, Hyun Jin; Feng, Huichen; Sarid, Ronit; Fernández-Figueras, María-Teresa; Tolstov, Yanis; Gjoerup, Ole; Mansukhani, Mahesh M.; Swerdlow, Steven H.; Chaudhary, Preet M.; Kirkwood, John M.; Nalesnik, Michael A.; Kant, Jeffrey A.; Weiss, Lawrence M.; Moore, Patrick S.; Chang, Yuan (2009). "Human Merkel cell polyomavirus infection I. MCV T antigen expression in Merkel cell carcinoma, lymphoid tissues and lymphoid tumors". International Journal of Cancer. 125 (6): 1243–9. PMID 19499546. doi:10.1002/ijc.24510.
- Van Der Meijden, Els; Janssens, René W. A.; Lauber, Chris; Bouwes Bavinck, Jan Nico; Gorbalenya, Alexander E.; Feltkamp, Mariet C. W. (2010). "Discovery of a New Human Polyomavirus Associated with Trichodysplasia Spinulosa in an Immunocompromized Patient". PLoS Pathogens. 6 (7): e1001024. PMC . PMID 20686659. doi:10.1371/journal.ppat.1001024.
- Kazem, S; van der Meijden, E; Feltkamp, MC (August 2013). "The trichodysplasia spinulosa-associated polyomavirus: virological background and clinical implications.". APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. 121 (8): 770–82. PMID 23593936. doi:10.1111/apm.12092.
- Scuda, N; Hofmann, J; Calvignac-Spencer, S; Ruprecht, K; Liman, P; Kühn, J; Hengel, H; Ehlers, B (May 2011). "A novel human polyomavirus closely related to the african green monkey-derived lymphotropic polyomavirus.". Journal of Virology. 85 (9): 4586–90. PMC . PMID 21307194. doi:10.1128/jvi.02602-10.
- Korup, Sarah; Rietscher, Janita; Calvignac-Spencer, Sébastien; Trusch, Franziska; Hofmann, Jörg; Moens, Ugo; Sauer, Igor; Voigt, Sebastian; Schmuck, Rosa; Ehlers, Bernhard (2013). "Identification of a Novel Human Polyomavirus in Organs of the Gastrointestinal Tract". PLoS ONE. 8 (3): e58021. Bibcode:2013PLoSO...858021K. PMC . PMID 23516426. doi:10.1371/journal.pone.0058021.
- Mishra, N; Pereira, M; Rhodes, RH; An, P; Pipas, JM; Jain, K; Kapoor, A; Briese, T; Faust, PL; Lipkin, WI (15 November 2014). "Identification of a novel polyomavirus in a pancreatic transplant recipient with retinal blindness and vasculitic myopathy.". The Journal of Infectious Diseases. 210 (10): 1595–9. PMC . PMID 24795478. doi:10.1093/infdis/jiu250.
- Gardner, SD; Field, AM; Coleman, DV; Hulme, B (19 June 1971). "New human papovavirus (B.K.) isolated from urine after renal transplantation.". Lancet. 1 (7712): 1253–7. PMID 4104714. doi:10.1016/s0140-6736(71)91776-4.
- Padgett, BL; Walker, DL; ZuRhein, GM; Eckroade, RJ; Dessel, BH (19 June 1971). "Cultivation of papova-like virus from human brain with progressive multifocal leucoencephalopathy.". Lancet. 1 (7712): 1257–60. PMID 4104715. doi:10.1016/S0140-6736(71)91777-6.
- Allander, T.; Andreasson, K.; Gupta, S.; Bjerkner, A.; Bogdanovic, G.; Persson, M. A. A.; Dalianis, T.; Ramqvist, T.; Andersson, B. (2007). "Identification of a Third Human Polyomavirus". Journal of Virology. 81 (8): 4130–6. PMC . PMID 17287263. doi:10.1128/JVI.00028-07.
- Gaynor, Anne M.; Nissen, Michael D.; Whiley, David M.; MacKay, Ian M.; Lambert, Stephen B.; Wu, Guang; Brennan, Daniel C.; Storch, Gregory A.; Sloots, Theo P.; Wang, David (2007). "Identification of a Novel Polyomavirus from Patients with Acute Respiratory Tract Infections". PLoS Pathogens. 3 (5): e64. PMC . PMID 17480120. doi:10.1371/journal.ppat.0030064.
- Nguyen, Khang D.; Lee, Eunice E.; Yue, Yangbo; Stork, Jiri; Pock, Lumir; North, Jeffrey P.; Vandergriff, Travis; Cockerell, Clay; Hosler, Gregory A. (2016-12-28). "Human polyomavirus 6 and 7 are associated with pruritic and dyskeratotic dermatoses". Journal of the American Academy of Dermatology. ISSN 1097-6787. PMID 28040372. doi:10.1016/j.jaad.2016.11.035.
- Ho, J; Jedrych, JJ; Feng, H; Natalie, AA; Grandinetti, L; Mirvish, E; Crespo, MM; Yadav, D; Fasanella, KE; Proksell, S; Kuan, SF; Pastrana, DV; Buck, CB; Shuda, Y; Moore, PS; Chang, Y (15 May 2015). "Human polyomavirus 7-associated pruritic rash and viremia in transplant recipients.". The Journal of Infectious Diseases. 211 (10): 1560–5. PMC . PMID 25231015. doi:10.1093/infdis/jiu524.
- Toptan, Tuna; Yousem, Samuel A.; Ho, Jonhan; Matsushima, Yuki; Stabile, Laura P.; Fernández-Figueras, Maria-Teresa; Bhargava, Rohit; Ryo, Akihide; Moore, Patrick S.; Chang, Yuan (25 February 2016). "Survey for human polyomaviruses in cancer". JCI Insight. 1 (2). PMC . PMID 27034991. doi:10.1172/jci.insight.85562.
- Siebrasse, E. A.; Reyes, A.; Lim, E. S.; Zhao, G.; Mkakosya, R. S.; Manary, M. J.; Gordon, J. I.; Wang, D. (2012). "Identification of MW Polyomavirus, a Novel Polyomavirus in Human Stool". Journal of Virology. 86 (19): 10321–6. PMC . PMID 22740408. doi:10.1128/JVI.01210-12.
- Buck, C. B.; Phan, G. Q.; Raiji, M. T.; Murphy, P. M.; McDermott, D. H.; McBride, A. A. (2012). "Complete Genome Sequence of a Tenth Human Polyomavirus". Journal of Virology. 86 (19): 10887. PMC . PMID 22966183. doi:10.1128/JVI.01690-12.
- Yu, Guixia; Greninger, Alexander L.; Isa, Pavel; Phan, Tung G.; Martínez, Miguel Angel; de la Luz Sanchez, Maria; Contreras, Juan Francisco; Santos-Preciado, José Ignacio; Parsonnet, Julie; Miller, Steve; Derisi, Joseph L.; Delwart, Eric; Arias, Carlos F.; Chiu, Charles Y. (2012). "Discovery of a Novel Polyomavirus in Acute Diarrheal Samples from Children". PLoS ONE. 7 (11): e49449. Bibcode:2012PLoSO...749449Y. PMC . PMID 23166671. doi:10.1371/journal.pone.0049449.
- Lim, Efrem S.; Reyes, Alejandro; Antonio, Martin; Saha, Debasish; Ikumapayi, Usman N.; Adeyemi, Mitchell; Stine, O. Colin; Skelton, Rebecca; Brennan, Daniel C.; Mkakosya, Rajhab S.; Manary, Mark J.; Gordon, Jeffrey I.; Wang, David (2013). "Discovery of STL polyomavirus, a polyomavirus of ancestral recombinant origin that encodes a unique T antigen by alternative splicing". Virology. 436 (2): 295–303. PMC . PMID 23276405. doi:10.1016/j.virol.2012.12.005.
- Dalianis, T; Hirsch, HH (15 March 2013). "Human polyomaviruses in disease and cancer.". Virology. 437 (2): 63–72. PMID 23357733. doi:10.1016/j.virol.2012.12.015.
- Van Ghelue M, Khan MT, Ehlers B, Moens U (2012). "Genome analysis of the new human polyomaviruses". Rev. Med. Virol. 22 (6): 354–77. PMID 22461085. doi:10.1002/rmv.1711.
- Egli, Adrian; Infanti, Laura; Dumoulin, Alexis; Buser, Andreas; Samaridis, Jacqueline; Stebler, Christine; Gosert, Rainer; Hirsch, Hans H. (2009). "Prevalence of Polyomavirus BK and JC Infection and Replication in 400 Healthy Blood Donors". The Journal of Infectious Diseases. 199 (6): 837–46. PMID 19434930. doi:10.1086/597126.
- Poulin, D. L.; Decaprio, J. A. (2006). "Is There a Role for SV40 in Human Cancer?". Journal of Clinical Oncology. 24 (26): 4356–65. PMID 16963733. doi:10.1200/JCO.2005.03.7101.
- Zur Hausen, Harald (2003). "Sv40 in human cancers—An endless tale?". International Journal of Cancer. 107 (5): 687. PMID 14566815. doi:10.1002/ijc.11517.
- Gazdar, AF; Butel, JS; Carbone, M (December 2002). "SV40 and human tumours: myth, association or causality?". Nature Reviews. Cancer. 2 (12): 957–64. PMID 12459734. doi:10.1038/nrc947.
- Carroll-Pankhurst, C; Engels, EA; Strickler, HD; Goedert, JJ; Wagner, J; Mortimer EA Jr. (November 2001). "Thirty-five year mortality following receipt of SV40- contaminated polio vaccine during the neonatal period.". Br J Cancer. 85 (9): 1295–7. PMC . PMID 11720463. doi:10.1054/bjoc.2001.2065.
- Shah, KV (15 January 2007). "SV40 and human cancer: a review of recent data.". International Journal of Cancer. 120 (2): 215–23. PMID 17131333. doi:10.1002/ijc.22425.
- Drachenberg, Cinthia B.; Hirsch, Hans H.; Ramos, Emilio; Papadimitriou, John C. (2005). "Polyomavirus disease in renal transplantation: Review of pathological findings and diagnostic methods". Human Pathology. 36 (12): 1245–55. PMID 16311117. doi:10.1016/j.humpath.2005.08.009.
- Viscidi, Raphael P.; Clayman, Barbara (2006). "Serological Cross Reactivity between Polyomavirus Capsids". In Ahsan, Nasimul. Polyomaviruses and Human Diseases. Advances in Experimental Medicine and Biology. 577. pp. 73–84. ISBN 978-0-387-29233-5. PMID 16626028. doi:10.1007/0-387-32957-9_5.
- Drews, Klaus; Bashir, Tarig; Dörries, Kristina (2000). "Quantification of human polyomavirus JC in brain tissue and cerebrospinal fluid of patients with progressive multifocal leukoencephalopathy by competitive PCR". Journal of Virological Methods. 84 (1): 23–36. PMID 10644084. doi:10.1016/S0166-0934(99)00128-7.
- Nickeleit, V; Hirsch, H. H.; Binet, I. F.; Gudat, F; Prince, O; Dalquen, P; Thiel, G; Mihatsch, M. J. (May 1999). "Polyomavirus infection of renal allograft recipients: from latent infection to manifest disease". Journal of the American Society of Nephrology. 10 (5): 1080–9. PMID 10232695.
- Randhawa, Parmjeet S.; Vats, Abhay; Zygmunt, Deborah; Swalsky, Patricia; Scantlebury, Velma; Shapiro, Ron; Finkelstein, Sydney (2002). "Quantitation of viral DNA in renal allograft tissue from patients with BK virus nephropathy1". Transplantation. 74 (4): 485–8. PMID 12352906. doi:10.1097/00007890-200208270-00009.
- Busam, K. J.; Jungbluth, A. A.; Rekthman, N; Coit, D; Pulitzer, M; Bini, J; Arora, R; Hanson, N. C.; Tassello, J. A.; Frosina, D; Moore, P; Chang, Y (2009). "Merkel Cell Polyomavirus Expression in Merkel Cell Carcinomas and Its Absence in Combined Tumors and Pulmonary Neuroendocrine Carcinomas". The American journal of surgical pathology. 33 (9): 1378–85. PMC . PMID 19609205. doi:10.1097/PAS.0b013e3181aa30a5.
- Kean, J. M.; Rao, S; Wang, M; Garcea, R. L. (2009). "Seroepidemiology of Human Polyomaviruses". PLoS Pathogens. 5 (3): e1000363. PMC . PMID 19325891. doi:10.1371/journal.ppat.1000363.
- Tolstov, Y. L.; Pastrana, D. V.; Feng, H; Becker, J. C.; Jenkins, F. J.; Moschos, S; Chang, Y; Buck, C. B.; Moore, P. S. (2009). "Human Merkel cell polyomavirus infection II. MCV is a common human infection that can be detected by conformational capsid epitope immunoassays". International Journal of Cancer. Journal International Du Cancer. 125 (6): 1250–6. PMC . PMID 19499548. doi:10.1002/ijc.24509.
- Pastrana, D. V.; Tolstov, Y. L.; Becker, J. C.; Moore, P. S.; Chang, Y; Buck, C. B. (2009). "Quantitation of Human Seroresponsiveness to Merkel Cell Polyomavirus". PLoS Pathogens. 5 (9): e1000578. PMC . PMID 19750217. doi:10.1371/journal.ppat.1000578.
- Carter, J. J.; Paulson, K. G.; Wipf, G. C.; Miranda, D; Madeleine, M. M.; Johnson, L. G.; Lemos, B. D.; Lee, S; Warcola, A. H.; Iyer, J. G.; Nghiem, P; Galloway, D. A. (2009). "Association of Merkel Cell Polyomavirus–Specific Antibodies with Merkel Cell Carcinoma". JNCI Journal of the National Cancer Institute. 101 (21): 1510–22. PMC . PMID 19776382. doi:10.1093/jnci/djp332.
- Gross, L. (1953). "A Filterable Agent, Recovered from Ak Leukemic Extracts, Causing Salivary Gland Carcinomas in C3H Mice". Experimental Biology and Medicine. 83 (2): 414–21. PMID 13064287. doi:10.3181/00379727-83-20376.
- Stewart, SE; Eddy, BE; Borgese, N (June 1958). "Neoplasms in mice inoculated with a tumor agent carried in tissue culture.". Journal of the National Cancer Institute. 20 (6): 1223–43. PMID 13549981.
- Eddy, Bernice E.; Stewart, Sarah E. (November 1959). "Characteristics of the SE Polyoma Virus". American Journal of Public Health and the Nations Health. 49 (11): 1486–92. PMC . PMID 13819251. doi:10.2105/AJPH.49.11.1486.
- Percy, Dean H.; Barthold, Stephen W. (2013). "Polyoma Virus Infection". Pathology of Laboratory Rodents and Rabbits (3rd ed.). John Wiley & Sons. ISBN 1118704630.
- Gottlieb, KA; Villarreal, LP (June 2001). "Natural biology of polyomavirus middle T antigen.". Microbiology and molecular biology reviews : MMBR. 65 (2): 288–318. PMC . PMID 11381103. doi:10.1128/mmbr.65.2.288-318.2001.
- Peretti, A; FitzGerald, PC; Bliskovsky, V; Pastrana, DV; Buck, CB (29 January 2015). "Genome Sequence of a Fish-Associated Polyomavirus, Black Sea Bass (Centropristis striata) Polyomavirus 1.". Genome announcements. 3 (1): e01476–14. PMC . PMID 25635011. doi:10.1128/genomeA.01476-14.
- López-Bueno, A; Mavian, C; Labella, AM; Castro, D; Borrego, JJ; Alcami, A; Alejo, A (20 July 2016). "Concurrence of iridovirus, polyomavirus and a unique member of a new group of fish papillomaviruses in lymphocystis disease affected gilthead seabream.". Journal of Virology. 90: JVI.01369–16. PMC . PMID 27440877. doi:10.1128/JVI.01369-16.