Difference between wild-type lentivirus and integrase-deficient lentivirus - (Jun/18/2013 )

Hi,
I don't know what is the difference between wild-type lentivirus and integrase-deficient lentivirus.
Are they used in different purpose? If so, what is it?
Anyone help
Thanks in advance.

So - what does integrase do? if you can find out that, it will tell you what you want to know...

Thank you, bob1, for a hint.
Do you mean integrase-deficient lentivirus (IDLV) doesn't integrate into host genome?
But some people used IDLV to capture virus-preferential integration site (PMID: 21822255).
It means that IDLV also integrate into host genome.
Because of this, I don't know the difference between two viruses/viral vector.
If you know something more, please let me know.
Thank you.