Human polyomavirus 7

Human polyomavirus 7
Virus classification
(unranked):	Virus
Realm:	Monodnaviria
Kingdom:	Shotokuvirae
Phylum:	Cossaviricota
Class:	Papovaviricetes
Order:	Sepolyvirales
Family:	Polyomaviridae
Genus:	Deltapolyomavirus
Species:	Human polyomavirus 7

Human polyomavirus 7 (HPyV7) is a virus of the polyomavirus family that infects human hosts. It was discovered in 2010 and is a common component of the skin flora in healthy adults.^[1] There is limited evidence from case reports linking the virus to a skin rash occurring in immunocompromised organ transplant recipients.^[2]

Discovery

HPyV7 was first discovered in 2010 by rolling circle amplification, a genetic technique that efficiently amplifies and detects circular DNA, such as a polyomavirus genome. It was identified as a component of skin flora in healthy adults, along with Merkel cell polyomavirus (which can cause Merkel cell cancer) and Human polyomavirus 6.^[1]

Taxonomy

HPyV7 is closely related to HPyV6, which was discovered at the same time; the two viruses' genomes share 68% sequence identity.^[1] In the 2015 taxonomic update to the polyomavirus group, the International Committee on Taxonomy of Viruses classified HPyV7 in the genus Deltapolyomavirus. This genus contains four viruses that infect humans: HPyV6, HPyV7, MW polyomavirus, and STL polyomavirus.^[3]

Prevalence

All known human polyomaviruses are fairly common in healthy adult populations and are usually asymptomatic. In studies that profile polyomavirus seroprevalence, or prevalence of detectable antibodies against viral proteins indicating either past or present exposure in immunocompetent adults, estimates of HPyV7 prevalence have ranged from approximately 35–85%, with evidence of low prevalence among children and increasing prevalence with age.^[1]^[4]^[5]^[6]^[7] The age-dependent pattern of seroprevalence featuring a decline at around six months old is consistent with the transmission of maternal antibodies.^[4] A study of cutaneous viruses in men found prevalence of HPyV7 DNA—indicating actively replicating virus—at around 2%.^[8] Another similar study reported HPyV7 DNA prevalence at around 14%, with 10% showing persistent viral shedding over time.^[9]

Clinical manifestations

As with many recently discovered human polyomaviruses, the clinical significance of HPyV7 is poorly characterized. Attempts to detect polyomaviruses in a variety of tumor types have consistently found that HPyV7 is either absent or present at very low viral loads, indicating that it is unlikely to be causally related to the tumor.^[9]

HPyV7 has been associated in case reports with a skin condition in immunocompromised patients—HPyV7-related epithelial hyperplasia^[10]—specifically lung transplant recipients on a regimen of immunosuppressive drugs. The reported skin manifestations consisted of severely pruritic (itchy) velvet-textured plaques initially interpreted clinically as drug side effects. Histological findings include viral particles contained in eosinophilic keratinocytes. Evidence of actively replicating HPyV7 was identified in affected tissue, supporting the hypothesis that the virus caused the rash.^[2]

References

^ ^a ^b ^c ^d Schowalter, Rachel M.; Pastrana, Diana V.; Pumphrey, Katherine A.; Moyer, Adam L.; Buck, Christopher B. (June 2010). "Merkel Cell Polyomavirus and Two Previously Unknown Polyomaviruses Are Chronically Shed from Human Skin". Cell Host & Microbe. 7 (6): 509–515. doi:10.1016/j.chom.2010.05.006. PMC 2919322. PMID 20542254.
^ ^a ^b Ho, J.; Jedrych, J. J.; Feng, H.; Natalie, A. A.; Grandinetti, L.; Mirvish, E.; Crespo, M. M.; Yadav, D.; Fasanella, K. E.; Proksell, S.; Kuan, S.-F.; Pastrana, D. V.; Buck, C. B.; Shuda, Y.; Moore, P. S.; Chang, Y. (17 September 2014). "Human Polyomavirus 7-Associated Pruritic Rash and Viremia in Transplant Recipients". Journal of Infectious Diseases. 211 (10): 1560–1565. doi:10.1093/infdis/jiu524. PMC 4425822. PMID 25231015.
^ 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 (6): 1739–50. doi:10.1007/s00705-016-2794-y. hdl:10037/13151. PMID 26923930.
^ ^a ^b van der Meijden, Els; Bialasiewicz, Seweryn; Rockett, Rebecca J.; Tozer, Sarah J.; Sloots, Theo P.; Feltkamp, Mariet C. W.; Kapoor, Amit (21 November 2013). "Different Serologic Behavior of MCPyV, TSPyV, HPyV6, HPyV7 and HPyV9 Polyomaviruses Found on the Skin". PLOS ONE. 8 (11): e81078. doi:10.1371/journal.pone.0081078. PMC 3836759. PMID 24278381.
^ Nicol, J. T. J.; Robinot, R.; Carpentier, A.; Carandina, G.; Mazzoni, E.; Tognon, M.; Touze, A.; Coursaget, P. (9 January 2013). "Age-Specific Seroprevalences of Merkel Cell Polyomavirus, Human Polyomaviruses 6, 7, and 9, and Trichodysplasia Spinulosa-Associated Polyomavirus". Clinical and Vaccine Immunology. 20 (3): 363–368. doi:10.1128/CVI.00438-12. PMC 3592346. PMID 23302741.
^ Šroller, Vojtěch; Hamšíková, Eva; Ludvíková, Viera; Musil, Jan; Němečková, Šárka; Saláková, Martina (July 2016). "Seroprevalence rates of HPyV6, HPyV7, TSPyV, HPyV9, MWPyV and KIPyV polyomaviruses among the healthy blood donors". Journal of Medical Virology. 88 (7): 1254–1261. doi:10.1002/jmv.24440. PMID 26630080. S2CID 22272324.
^ 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. doi:10.1093/aje/kwv155. PMC 5006224. PMID 26667254.
^ Hampras, S. S.; Giuliano, A. R.; Lin, H.-Y.; Fisher, K. J.; Abrahamsen, M. E.; McKay-Chopin, S.; Gheit, T.; Tommasino, M.; Rollison, D. E. (11 November 2014). "Natural History of Polyomaviruses in Men: The HPV Infection in Men (HIM) Study". Journal of Infectious Diseases. 211 (9): 1437–1446. doi:10.1093/infdis/jiu626. PMC 4462655. PMID 25387582.
^ ^a ^b Ehlers, Bernhard; Wieland, Ulrike (August 2013). "The novel human polyomaviruses HPyV6, 7, 9 and beyond". APMIS. 121 (8): 783–795. doi:10.1111/apm.12104. PMID 23656581. S2CID 1706956.
^ Toptan, Tuna; et al. (2016). "Survey for human polyomaviruses in cancer". JCI Insight. 1 (2): e85562. doi:10.1172/jci.insight.85562. PMC 4811373. PMID 27034991.