MW polyomavirus

MWPyV was discovered in 2012 and independently reported by three different research groups under the names "Malawi polyomavirus", "Mexico polyomavirus", and "Human polyomavirus 10". The first group to publish gave the virus the "Malawi" designation based on the geographic location of the index case, a healthy child from Malawi; the designation "MW polyomavirus" has been included in the International Committee on Taxonomy of Viruses proposed classification of polyomaviruses. It was the 10th human polyomavirus to be discovered.{{cite journal|last1=Polyomaviridae Study Group of the International Committee on Taxonomy of|first1=Viruses|last2=Calvignac-Spencer|first2=S|last3=Feltkamp|first3=MC|last4=Daugherty|first4=MD|last5=Moens|first5=U|last6=Ramqvist|first6=T|last7=Johne|first7=R|last8=Ehlers|first8=B|title=A taxonomy update for the family Polyomaviridae.|journal=Archives of Virology|date=29 February 2016|doi=10.1007/s00705-016-2794-y|pmid=26923930|volume=161|issue=6|pages=1739–50|doi-access=free|hdl=10037/13151|hdl-access=free}}

The organization of the MWPyV genome is typical of polyomaviruses. At around 4.9 kilobase pairs in length, it contains genes for the small tumor antigen and large tumor antigen and three viral coat proteins, VP1, VP2, and VP3. Different MWPyV isolates have a relatively large amount of sequence variation, up to approximately 5%; this pattern is similar to that seen in BK polyomavirus.{{cite journal|last1=Rockett|first1=Rebecca J.|last2=Sloots|first2=Theo P.|last3=Bowes|first3=Sharleen|last4=O’Neill|first4=Nicholas|last5=Ye|first5=Suifang|last6=Robson|first6=Jenny|last7=Whiley|first7=David M.|last8=Lambert|first8=Stephen B.|last9=Wang|first9=David|last10=Nissen|first10=Michael D.|last11=Bialasiewicz|first11=Seweryn|last12=Qiu|first12=Jianming|title=Detection of Novel Polyomaviruses, TSPyV, HPyV6, HPyV7, HPyV9 and MWPyV in Feces, Urine, Blood, Respiratory Swabs and Cerebrospinal Fluid|journal=PLOS ONE|date=8 May 2013|volume=8|issue=5|pages=e62764|doi=10.1371/journal.pone.0062764|pmid=23667518 |pmc=3648528|bibcode=2013PLoSO...862764R|doi-access=free}}

Phylogenetic analyses of the MWPyV genome suggest different ancestries for the large tumor antigen and the major capsid protein VP1, implying that the virus might have evolved from an ancestral recombination event.

In the 2015 taxonomic update to the polyomavirus group, the International Committee on Taxonomy of Viruses classified MWPyV in the genus Deltapolyomavirus. This genus contains four viruses that infect humans: HPyV6, HPyV7, MW polyomavirus, and STL polyomavirus.

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 MWPyV prevalence have ranged from approximately 40-85%.{{cite journal|last1=Nicol|first1=J. T. J.|last2=Leblond|first2=V.|last3=Arnold|first3=F.|last4=Guerra|first4=G.|last5=Mazzoni|first5=E.|last6=Tognon|first6=M.|last7=Coursaget|first7=P.|last8=Touze|first8=A.|title=Seroprevalence of Human Malawi Polyomavirus|journal=Journal of Clinical Microbiology|date=30 October 2013|volume=52|issue=1|pages=321–3|doi=10.1128/JCM.02730-13|pmid=24172149 |pmc=3911455

|url=http://prodinra.inra.fr/ft/EB69846E-57C6-402B-820A-4BFA2E7E0442}}{{cite journal|last1=Berrios|first1=Christian|last2=Jung|first2=Joonil|last3=Primi|first3=Blake|last4=Wang|first4=Michael|last5=Pedamallu|first5=Chandrasekhar|last6=Duke|first6=Fujiko|last7=Marcelus|first7=Christina|last8=Cheng|first8=Jingwei|last9=Garcea|first9=Robert L.|last10=Meyerson|first10=Matthew|last11=DeCaprio|first11=James A.|last12=Sandri-Goldin|first12=R. M.|title=Malawi Polyomavirus Is a Prevalent Human Virus That Interacts with Known Tumor Suppressors|journal=Journal of Virology|date=1 January 2015|volume=89|issue=1|pages=857–862|doi=10.1128/JVI.02328-14|pmid=25320321 |pmc=4301141}}{{cite journal|last1=Šroller|first1=Vojtěch|last2=Hamšíková|first2=Eva|last3=Ludvíková|first3=Viera|last4=Musil|first4=Jan|last5=Němečková|first5=Šárka|last6=Saláková|first6=Martina|title=Seroprevalence rates of HPyV6, HPyV7, TSPyV, HPyV9, MWPyV and KIPyV polyomaviruses among the healthy blood donors|journal=Journal of Medical Virology|date=July 2016|volume=88|issue=7|pages=1254–1261|doi=10.1002/jmv.24440|pmid=26630080|s2cid=22272324}} Like most human polyomaviruses, MWPyV infection appears to be acquired in early childhood.{{cite journal|last1=Rockett|first1=Rebecca J.|last2=Bialasiewicz|first2=Seweryn|last3=Mhango|first3=Lebogang|last4=Gaydon|first4=Jane|last5=Holding|first5=Rebecca|last6=Whiley|first6=David M.|last7=Lambert|first7=Stephen B.|last8=Ware|first8=Robert S.|last9=Nissen|first9=Michael D.|last10=Grimwood|first10=Keith|last11=Sloots|first11=Theo P.|title=Acquisition of Human Polyomaviruses in the First 18 Months of Life|journal=Emerging Infectious Diseases|date=February 2015|volume=21|issue=2|pages=365–7|doi=10.3201/eid2102.141429|pmid=25626138 |pmc=4313659}} Studies of the presence of viral DNA, indicating active viral replication, suggest MWPyV prevalence in the range of 1-10% of children,{{cite journal|last1=Ehlers|first1=Bernhard|last2=Wieland|first2=Ulrike|title=The novel human polyomaviruses HPyV6, 7, 9 and beyond|journal=APMIS|date=August 2013|volume=121|issue=8|pages=783–795|doi=10.1111/apm.12104|pmid=23656581|s2cid=1706956}} with low or no detection of active viral replication in adults.

As with many recently discovered human polyomaviruses, the clinical significance of MWPyV is poorly characterized. It has been repeatedly found in stool samples from both healthy children and those suffering from diarrhea, with no obvious causal association.{{cite journal|last1=Dalianis|first1=Tina|last2=Hirsch|first2=Hans H.|title=Human polyomaviruses in disease and cancer|journal=Virology|date=March 2013|volume=437|issue=2|pages=63–72|doi=10.1016/j.virol.2012.12.015 |pmid=23357733

|doi-access=}} MWPyV has also been reported in respiratory secretions in children and may be associated with mild upper respiratory infections in this population. One of the three original reports of MWPyV isolated it from samples of warts on a patient diagnosed with WHIM syndrome; later the closely related STL polyomavirus was isolated from the same surgical sample.{{cite journal|last1=Pastrana|first1=D. V.|last2=FitzGerald|first2=P. C.|last3=Phan|first3=G. Q.|last4=Raiji|first4=M. T.|last5=Murphy|first5=P. M.|last6=McDermott|first6=D. H.|last7=Velez|first7=D.|last8=Bliskovsky|first8=V.|last9=McBride|first9=A. A.|last10=Buck|first10=C. B.|title=A Divergent Variant of the Eleventh Human Polyomavirus Species, Saint Louis Polyomavirus|journal=Genome Announcements|date=24 October 2013|volume=1|issue=5|pages=e00812-13|doi=10.1128/genomeA.00812-13 |pmid=24158550 |pmc=3813180}} This rare disease is associated with susceptibility to human papillomavirus infections, but it is unclear whether the presence of MWPyV in this setting is clinically significant.

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{{Human polyomaviruses}}

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Category:Polyomaviridae