Superinfection question

[Michael Poidinger]

In article <1994Nov9.152152.1 at cc.newcastle.edu.au> mdcabl at cc.newcastle.edu.au writes:
>From: mdcabl at cc.newcastle.edu.au
>Subject: Superinfection question
>Date: 9 Nov 94 15:21:52 +1100

>Hi all,
>Just wondering.  What happens when two different species of virus
>attempt to infect the same cell? Is there still a block on superinfection? I
>especially wonder if perhaps a cytoplasmic virus can replicate in the same cell
>if it already has an retro virus infection like AIDS.  I have been told that
>non-HIV viral infection in AIDS pateints is a problem.  Are the two viruses
>competing for the same cells or just finding different parts of the host to
>replicate in?  Finally has anyone researched how viruses which co-exist in the
>same host compete against each other, if at all?  I couldn't find anything on
>medline on this.  Any theories or speculations are welcome.
>Cheers,
>Allen Black
>Dept. of Pathology
>Univ. of Newcastle

Two viruses of the same genus will probably interfere with each others 
replication within a cell, it is certainly true of flaviviruses and 
alphaviruses. Within a host I think that given the number of cells in the body 
vs the number of cells actually infected, the chance of coinfection being a 
significant factor is rather low.

Aids and similar viruses that suppress the immune system allow other viruses 
to proliferate, hence the high incidence of life threatening cytomegalovirus 
in patients with ARC. This is not so much an interaction between the viruses 
but rather one virus taking advantage of the immune modulation of another

Vaccinia virus, and other viruses which cause shut down of cellular synthesis 
will interfere with viruses that require host synthesis for replication, again 
vaccinia interferes with flavivirus replication.  Interestingly,  
poliovirus (another virus that shuts down cellular translation) interferes 
with some but not all flaviviruses.

Finally, persistently infected cell monolayers in which the persistence is due 
to defective interfering particles are resistant to superinfection by similar 
viruses.

There.  my 0.02

Mike


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Dr Mike Poidinger  | Hey Christian God, get out of my face
Microbiology          | Your holy ghost is a curse on the human race        
UWA, Australia	     | I'd like to string you up one more time,                 
                               | No stupid sacrament, no pissy wine (Snog)
mikep at uniwa.uwa.edu.au
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