If you had the zinc finger nuclease (ZFN) reagents in your hands right now to allow you to knock out – dhfr, GS, fut8, neu3, bax/bak, lactate dehydrogenase A (LDHA), or RACK 1? What would you do? You can directly affect selection, fucosylation, sialylation, apoptosis, waste product production – either alone or in combination (so-called trait stacking).
If you could do it, what genes would you want to manipulate? And what combinations would be interesting for your system and proteins of interest?
I’d like to get some feedback. It would be great if this could be discussed on the blog, but would even like private feedback if musts be (as my UK colleagues say).
These are the type of questions that we are pondering. And, we’re looking for market confirmation as well as potentially collaborators who might want to look at these – or even other genes of interest
Let’s hear from you out there.
Posted by Bruce Lehr February 4, 2010


Thanks for your comments Biotechnica. With regard to the tail end of your post, we definitely would be monitoring growth rates, productivity and protein quality as we are modifying traits. Wouldn't do us much good in most instances to adversely affect these. With regard to medium composition, our strategy is to move toward chemically-defined, minimalist platforms. We'd just as soon keep all expensive and non-value added components out of the mix. The idea is to be able to create more consistent products, thoroughly characterize the raw materials, and to manage the supply chain. We're shooting for industrial hardy products.
Finally, on your "open sharing" comment. Yes, it's tough in this industry due to perceived IP issues both the real and the overhyped. I saw this great quote by Walt Disney when asked if he were afraid to share so many of his ideas with people. He said, "Those were last year's ideas." I like that.
Posted by: Bruce Lehr | 02/06/2010 at 10:23 AM
It is amazing how hard it is to find bloggers from the Biotech industry. Part of it is the fact that big Biotech firms do not like to share their research problems or solutions unless it is a patent disclosure!
For the systems I work on, it would be beneficial to get rid of apoptosis inducing proteins for sure- that would hopefully increase the cell densities and thereby improve protein production numbers. Knocking down other genes would depend upon whether one is looking for a more stringent selection in a DHFR amplification or GS system. The whole mix of what can be removed from the picture depends upon the problem.
Most scientists would like to use one or the other approach for different projects depending upon whether a defucosylated or sialylated antibody /other protein was the end goal.
Combination cell lines would certainly help for solving a wide range of problems as long as trait- stacking does not compromise other cell characteristics such as growth rate and expensive/ FDA unapproveable supplement requirements :-).
Posted by: Biotechnica | 02/05/2010 at 01:13 PM
1) test them with an in vitro cleavage assay
2) test them in culture for off-site cleavage
Posted by: Bodenski | 02/05/2010 at 10:15 AM