I just would like to know some opinions on this article from Dr. Paula:
http://www.drpaula.com/news/011400.html#2
http://archive.twst.com/notes/articles/gan012.html
“We have what we call a “pilot plant” facility. In this case, the milk is collected conventionally from genetically modified sheep, and the human protein, alpha-1-antitrypsin, or AAT, is purified from this milk to 99.99-plus percent pure. We’re doing this at just over a kilogram a week, which, for most recombinant proteins is a huge quantity. And we’ve taken that material and used it in clinical trials for the treatment of cystic fibrosis patients, and we’re currently in clinical trials, looking at its use for so-called congenital deficiency, i.e., people who don’t make enough - or any - AAT of their own. So AAT produced by transgenic sheep is in clinical trials for two indications.”
This company seems to be developing these genes and animals for pharmaceutical purposes. Taking the protiens out of the product for medicines rather than producing it for the milk itself. It certainly seems possible that with breeding much larger numbers that the possibility exists for producing marketable “human” milk. This quote is talking about sheep though, I’ll see what else I can find.
http://www.gene.ch/gentech/1997/Sep-Oct/msg00124.html
From the above site…
"Genzyme Transgenics said the first protein to be produced in the cow
milk under the agreement would be human serum albumin, which is used
to maintain fluid balance in the blood.
The protein will then be purified out of the milk for medical use.
Human serum albumin is currently derived from pooled human plasma.
About 440 metric tonnes of plasma-derived albumin are used annually
worldwide, with annual sales of about $1.5 billion.
Serum albumin is given to patients who have lost a great deal of blood
and is used widely in a range of other problems from extreme
malnutrition to burns."
This is an older Reuters article about another company working on the same type of thing. They also seem to be producing it for it’s protein constituents rather than the milk as a whole.
Considering the amount of money both of these firms are putting into the technology it would seem that its’ primary use would be medical. I do agree that somewhere down the road they might license it out (I’m guessing they’re putting patents on some of these processes) to someone else who would make “human” milk and sell it as such.
Here is something more recent and specific about what they are doing and hoping to accomplish.
“Towards this goal, scientists at the US division of PPL Therapeutics in Blacksburg, VA have used nuclear transfer techniques similar to those used in sheep to produce a number of cloned cattle from genetically elite Holstein lines (1998-1999, unpublished). Targets for genetic modification in cows include: knockout of the bovine prion (PrP) gene to produce cattle resistant to BSE (mad cow disease); knockout of allergenic milk protein genes for use in the production of infant formulas; and knockout of the bovine serum albumin gene and subsequent replacement with the human serum albumin equivalent. This substitution allows cost-effective production of large quantities of this important human blood protein in cows’ milk.
In addition to these specific examples, there are broad benefits from use of gene targeting methodologies in the area of transgenic protein production. A number of companies have human therapeutic protein products that are isolated from the milk of transgenic livestock (sheep, cows, goats, and rabbits) in late-stage clinical trials. Genzyme Transgenics has human anti-thrombin III (a blood coagulation inhibitor) in Phase III trials; PPL Therapeutics has AAT (alpha-1-antitrypsin) for treatment of cystic fibrosis in Phase II trials; and Pharming has alpha-glucosidase for treatment of Pompe’s Disease in Phase I trials. All of these products were produced via microinjection of the desired human gene, under control of a mammary gland specific promoter, into fertilized zygotes.”
From the site…
http://www.nbiap.vt.edu/news/1999/news99.nov.html#nov9905