- JC virus
Taxobox
virus_group = i
familia = "Polyomaviridae "
genus = "Polyomavirus "
species = "JC polyomavirus"The JC virus or John Cunningham virus (JCV) is a type of humanpolyomavirus (formerly known as papovavirus) and is genetically similar toBK virus andSV40 . It was discovered in1971 and named after the two initials of a patient withprogressive multifocal leukoencephalopathy (PML). The virus causes PML and other diseases only in cases ofimmunodeficiency , as inAIDS , orimmunosuppression , as inorgan transplant patients.Epidemiology
The virus is very common in the general population, infecting 70 to 90 percent of humans; most people acquire JCV in childhood or adolescence
cite journal
author=Padgett, B.L. and Walker, D.L. | title=Prevalence of antibodies in human sera against JC virus, an isolate from a case of progressive multifocal leukoencephalopathy | journal=J. Infect. Dis. | year=1973 | pages=467-470 | volume=127 | issue=4 | pmid=4571704] . It is found in high concentrations in urban sewage worldwide, leading some researchers to suspect contaminated water as a typical route of infection
cite journal
author=Bofill-Mas, S., Formiga-Cruz, M., Clemente-Casares, P., Calafell, F. and Girones, R. | title=Potential transmission of human polyomaviruses through the gastrointestinal tract after exposure to virions or viral DNA | journal=J. Virol. | year=2001 | pages=10290-10299 | volume=75 | issue=21 | pmid=11581397] .
Minor genetic variations are found consistently in different geographic areas; thus, genetic analysis of JC virus samples has been useful in tracing the history of human migration
cite journal
author=Pavesi, A. | title=Utility of JC polyomavirus in tracing the pattern of human migrations dating to prehistoric times. | journal=J. Gen. Virol. | year=2005 | pages=1315-1326 | volume=86 | issue=Pt 5 | pmid=15831942] .
Infection and pathogenesis
The initial site of infection may be the
tonsil s,cite journal
author=Monaco, M.C., Jensen, P.N., Hou, J., Durham, L.C. and Major, E.O. | title=Detection of JC virus DNA in human tonsil tissue: evidence for site of initial viral infection | journal=J. Virol. | year=1998 | pages=9918-9923 | volume=72 | issue=12 | pmid=9811728] or possibly the
gastrointestinal tract .cite journal
author=Bofill-Mas, S., Formiga-Cruz, M., Clemente-Casares, P., Calafell, F. and Girones, R. | title=Potential transmission of human polyomaviruses through the gastrointestinal tract after exposure to virions or viral DNA | journal=J. Virol. | year=2001 | pages=10290-10299 | volume=75 | issue=21 | pmid=11581397] The virus then remains latent in the gastrointestinal tract
cite journal
author=Ricciardiello, L., Laghi, L., Ramamirtham, P., Chang, C.L., Chang, D.K., Randolph, A.E. and Boland, C.R. | title=JC virus DNA sequences are frequently present in the human upper and lower gastrointestinal tract | journal=Gastroenterology | year=2000 | pages=1228-1235 | volume=119 | issue=5 | pmid=11054380] and can also infect the tubular epithelial cells in the
kidney s, [Harvey, R. (2007) Microbiology Philadelphia, Lippincott Williams & Wilkins.] where it continues to reproduce, shedding virus particles in the urine.JCV can cross the
blood-brain barrier into thecentral nervous system , where it infectsoligodendrocyte s andastrocyte s, possibly through the 5-HT2Aserotonin receptor.cite journal
author=Elphick, G.F., Querbes, W., Jordan, J.A., Gee, G.V., Eash, S., Manley, K., Dugan, A., Stanifer, M., Bhatnagar, A., Kroeze, W.K., Roth, B.L. and Atwood, W.J. | title=The human polyomavirus, JCV, uses serotonin receptors to infect cells | journal=Science | year=2004 | pages=1380-1383 | volume=306 | issue=5700 | pmid=15550673] JC viral DNA can be detected in both non-PML affected as well as PML-affected (see below) brain tissue.
cite journal
author=White, F.A., 3rd., Ishaq, M., Stoner, G.L. and Frisque, R.J. | title=JC virus DNA is present in many human brain samples from patients without progressive multifocal leukoencephalopathy | journal=J. Virol. | year=1992 | pages=5726-5734 | volume=66 | issue=10 | pmid=1326640]
Immunodeficiency or immunosuppression allows JCV to reactivate. In the
brain it causes the usually fatalprogressive multifocal leukoencephalopathy , or PML, by destroying oligodendrocytes. Whether this represents the reactivation of JCV within the CNS or seeding of newly reactivated JCV via blood or lymphatics is unknown. [http://www.emedicine.com/neuro/topic450.htm] Several studies since 2000 have suggested that the virus is also linked tocolorectal cancer , as JCV has been found in malignant colon tumors, but these findings are still controversial.cite journal
author=Theodoropoulos, G., Panoussopoulos, D., Papaconstantinou, I., Gazouli, M., Perdiki, M., Bramis, J. and Lazaris, ACh. | title=Assessment of JC polyoma virus in colon neoplasms | journal=Dis. Colon. Rectum. | year=2005 | pages=86-91 | volume=48 | issue=1 | pmid=15690663]
Drug Interactions
The boxed warning for the drug
rituximab (Rituxan, co-marketed by Genentech BioOncology and Biogen Idec) includes that JC virus infection resulting in progressive multifocal leukoencephalopathy and death has been reported in patients treated with the drug [http://www.gene.com/gene/products/information/pdf/rituxan-prescribing.pdf] .References
External links
[http://www.ncbi.nlm.nih.gov/sites/entrez?Db=genome&Cmd=ShowDetailView&TermToSearch=10684 NCBI - JC Virus Complete Genome]
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