Viral Vectors in Mammalian Cell Transduction

[LUser <]

I am working with a non-continuous line of cultured mammalian cells, namely 
adult bone marrow mesenchymal "stem" cells.

The big thing for long-term tracking of engrafted cells is to label them 
with reporters like a GFP variant or LacZ.  

Transduction seems to be the best strategy to get the gene in, since we 
want high efficiency of gene delivery in cells that have limited population 
doublings.  

There is no one viral vector to be used.  Some use retroviral vectors 
because they want stable transfection (integration)....why?  I don't know 
for a cell line that will not be continuous.  Others have used adenovirus 
(only transient expression here).

If I understand correctly, adenovirus seems to make the most sense.  
Infection with replication-defective virions under the right conditions is 
likely to produce higher levels of expression (transcription/translation) 
than use of a retrovirus who integrated proviral form may not be a high 
level expressor.  I am led to believe that the risk of adenoviral vector 
labeling is that expression may be lost within the time period it is 
wanted:  these grafted stem cells may be in the tissues quite a few months 
before the tissues are examined, and the reporter expression must be active 
to find the cell in the tissue.

I appreciate any corrections to any misunderstandings I have.