SV40

[Giovanni Maga]

In article <199502012021.PAA26388 at hobbes.kzoo.edu>, ogston at HOBBES.KZOO.EDU
(Walter Ogston) wrote:

> >  gibbs at fas.harvard.edu (James Gibbs)
> 
> Writes:
> 
> > There are two human viruses that are very, very close in sequence, if not
> > identical to SV40. One is called JK virus I think (JC?), the other's name
> > escapes me. One infects the kidney, the other infects the brain. Sorry I 
> > couldn't be more certain. Maybe someone else here knows.
> > 
> The human viruses are JC and BK.  Fields' Virology or Fundamental
> Virology is a good place to look for info like this.  Also White and
> Fenner, Medical Virology, has a new edition out just recently.  
> 

> ----------------------------------------------------------------------
> Walter Ogston				ogston at hobbes.kzoo.edu
> Department of Biology			Phone: (616)337-7010
> Kalamazoo College			Fax:   (616)337-7251
> Kalamazoo, MI 49006-3295

JC and BK are the only (at least as I know) polyoma viruses known to infect
humans. They are found in a high percentage of the human population
examined so far (70% has Abs against them). It seems that the primary
infection occurs in the upper respiratory tract usually without relevant
(or any) clinical signs. Then both viruses induce latent infection in the
kidney. This is absolutely asymptomatic (as far as we know) for patients
with normal immune response, but immunosuppression (after transplantation)
or immunodepression gives reactivation of viruses which in turn leads to
severe pathologies of the uro-genital tract (BK, especially in patients
after kidney transplantation) or of the brain (JC causes the rare but
deadly PML).
As far as I know, they are not actually identical to SV40. Probably James
Gibbs was referring to other two newly discovered polyomaviruses associated
to PML in humans but more related to SV40 than to JC. They have been named
PML-SV40 viruses, but their pathogenic role is still to be determined. BK
and JC can induce malignant transformation in cell cultures, but they have
not yet been correlated to any specific tumor in humans.
G.Maga, Biochemistry
University of Zuerich
maga at vetbio.unizh.ch