Can viruses be used to diminish the effects of genes?

[bioquest]

Can viruses be used to diminish the effects of genes? My friend said they couldn't be because we didn't understand enough about the mechanisms behind viruses and she gave some other reasons...but she was in a hurry and she might not have understood what i was asking...so I was wondering if a virus could be to used to stop/lower the effect of a gene or two, (in things that arent embroys) and why or why not

thanks

 

[iansmith]

Scientist already use viruses but these viruses have been engineered/modified to suit the purpose. However, these viruses, more often than not, do not replicate.

 

[bioquest]

Do they not replicate for safety purposes?
A virus that replicates could be used/created though right? (To diminish the effects of a gene)

 

[Andy Resnick]

I'm fairly sure that the guts of the virus are completely replaced with siRNA, leaving the virus only able to efficiently inject the cargo into a cell. Otherwise the cure would be worse than the disease?

http://en.wikipedia.org/wiki/Lentivirus

 

[bioquest]

a virus couldn't be used to affect genes in every cell type because it would probably be too tissue-specific right?