Human polyomavirus 6

Human polyomavirus 6 (HPyV6) is a virus of the polyomavirus family that infects human hosts. It was discovered in 2010 and is a component of the skin flora in healthy adults.[1]

Human polyomavirus 6
Virus classification
(unranked):	Virus
Realm:	Monodnaviria
Kingdom:	Shotokuvirae
Phylum:	Cossaviricota
Class:	Papovaviricetes
Order:	Sepolyvirales
Family:	Polyomaviridae
Genus:	Deltapolyomavirus
Species:	Human polyomavirus 6

Discovery

HPyV6 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 7.[1]

Taxonomy

HPyV6 is closely related to HPyV7, 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 HPyV6 as the type species of the genus Deltapolyomaviridae. This group contains only four viruses, all of which infect humans: HPyV6, HPyV7, MW polyomavirus, and STL polyomavirus.[2]

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 HPyV6 prevalence have ranged from approximately 60–85%, with evidence of low prevalence among children and increasing prevalence with age.[1][3][4][5][6] The age-dependent pattern of seroprevalence featuring a decline at around six months old is consistent with the transmission of maternal antibodies.[3] A study of cutaneous viruses in men found prevalence of HPyV6 DNA—indicating actively replicating virus—at around 12%.[7] Another similar study reported HPyV6 DNA prevalence at around 30%, with 24% showing persistent viral shedding over time.[8]

Clinical manifestations

As with many recently discovered human polyomaviruses, the clinical significance of HPyV6 is poorly characterized. Attempts to detect polyomaviruses in a variety of tumor types have consistently found that HPyV6 is either absent or present at very low viral loads, indicating that it is unlikely to be causally related to the tumor.[8]

HPyV6, and the closely related HPyV7, have been linked to skin rashes known as pruritic and dyskeratotic dermatoses in immunocompromised patients in case reports, though a causal association has not yet been established.[9][10]

References

1. 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.
2. 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. PMID 26923930.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. Nguyen, Khang D.; Lee, Eunice E.; Yue, Yangbo; Stork, Jiri; Pock, Lumir; North, Jeffrey P.; Vandergriff, Travis; Cockerell, Clay; Hosler, Gregory A. (28 December 2016). "Human polyomavirus 6 and 7 are associated with pruritic and dyskeratotic dermatoses". Journal of the American Academy of Dermatology. 76: 932–940.e3. doi:10.1016/j.jaad.2016.11.035. ISSN 1097-6787. PMC 5392424. PMID 28040372.