Inducible shRNA knockdown in primary cells - (Aug/02/2006 )

Hi,

I am designing an experiment where i need to have an inducible knockdown of a gene of interest in primary cells.

I have considered:

1. siRNA/Antisense oligos
Cons: The effeciency of transfection in primary cells is too low and it is not inducible

2. Vector mediated shRNA:
There are commerically available Dox inducible retroviral( Clonetech) and lentiviral( Invitrogen) systems available. However, I have two concerns-
i) The leakiness- where I have read that there is significant knockdown even in the absence of the induction
ii) The promoter (U6/H1) are not very tightly regulated, thus the knockdown effeciency is low when compared to CMV etc.

3. Does anyone know of an inducible adenoviral shrna?

If anyone has experience or suggestion in this regard, kindly share it with me.

Thanks,
Anita.