JC virus 767912 222784612 2008-07-01T02:39:51Z Sabedon 2083035 /* External Links */ [[Category:Microbiology]] {{Taxobox | virus_group = i | familia = ''[[Polyomaviridae]]'' | genus = ''[[Polyomavirus]]'' | species = '''''JC polyomavirus''''' }} The '''JC virus''' or John Cunningham virus (JCV) is a type of human [[polyomavirus]] (formerly known as papovavirus) and is genetically similar to [[BK virus]] and [[SV40]]. It was discovered in [[1971]] and named after the two initials of a patient with [[progressive multifocal leukoencephalopathy]] (PML). The virus causes PML and other diseases only in cases of [[immunodeficiency]], as in [[AIDS]], or [[immunosuppression]], as in [[organ 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 <ref name=Padget>{{ 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 }}</ref>. It is found in high concentrations in urban sewage worldwide, leading some researchers to suspect contaminated water as a typical route of infection <ref name=Bofill>{{ 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 }}</ref>. 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 <ref name=Pavesi>{{ 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 }}</ref>. ==Infection and pathogenesis== The initial site of infection may be the [[tonsil]]s <ref name=Monaco>{{ 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 }}</ref>, or possibly the [[gastrointestinal tract]] <ref name=Bofill>{{ 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 }}</ref>. The virus then remains latent in the gastrointestinal tract <ref name=Ricardiello>{{ 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 }}</ref> and can also infect [[epithelium|epithelial]] cells in the [[kidney]]s, where it continues to reproduce, [[viral shedding|shedding virus]] particles in the urine. JCV can cross the [[blood-brain barrier]] into the [[central nervous system]], where it infects [[oligodendrocyte]]s and [[astrocyte]]s, possibly through the [[5-HT receptor|5-HT<sub>2A</sub>]] [[serotonin]] [[receptor (biochemistry)|receptor]] <ref name=Elphick>{{ 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 }}</ref>. It is found within the brain even in people with no symptoms <ref name=White>{{ 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 }}</ref>. When immunodeficiency or immunosuppression allows JCV to reactivate, it attacks the previously infected tissues. In the kidneys, this results in hemorrhagic [[cystitis]] and [[ureter]]al [[stenosis]]; in the [[brain]], it causes the usually fatal [[progressive multifocal leukoencephalopathy]] or PML by destroying oligodendrocytes. Several studies since 2000 have suggested that the virus is also linked to [[colorectal cancer]], as JCV has been found in malignant [[colon (anatomy)|colon]] tumors, but these findings are still controversial <ref name=Theodoropoulos>{{ 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 }}</ref>. ==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== <references/> ==External Links== [[Category:Viruses]] [[Category:Polyomaviruses]] [[Category:Microbiology]] [http://www.ncbi.nlm.nih.gov/sites/entrez?Db=genome&Cmd=ShowDetailView&TermToSearch=10684 NCBI - JC Virus Complete Genome] [[de:JC-Virus]] [[id:Virus JC]] [[nl:JC-virus]] [[sv:JC-virus]]