Livestock may
help treat ailments, including HIV

Livestock whose genes have been manipulated could play a critical role in developing new medications and cheaper treatments for human ailments, scientists said Monday.

However, the use of transgenic animals, which have foreign DNA integrated into their genetic information, remains controversial and faces regulatory, economic, and societal challenges.

Education about the advantages and the challenges that accompany the new technology ''is the key to public understanding,'' according to a paper from the Council for Agricultural Science and Technology. The Ames, Iowa-based international consortium of 38 scientific and professional societies assembles and interprets scientific information for policymakers, regulators, lawmakers, media, and the public and private sectors.

Carol L. Keefer, associate professor of embryology and biotechnology at the University of Maryland, is chairwoman of a CAST task force that released a paper on Monday titled ''The Role of Transgenic Livestock in the Treatment of Human Disease.'' It's part of a series on how biotechnology is being used in animal agriculture.

She said transgenic animals can be used to produce proteins and antibodies in their blood and milk, or the animals can be used as subjects to better study human diseases.

''Both approaches can provide significant advances in the development of new treatments,'' she said.

Critics of the new technology range from health professionals who worry over its safety to members of animal welfare groups who say it further exploits livestock.

Bruce Friedrich, a vice president of People for the Ethical Treatment of Animals, called the technology ''Frankenstein science'' that leads to the death of many laboratory animals. He said there can be terrifying consequences for humans if diseases cross species barriers.

''It's reckless science to expose humans and animals to a litany of potential side effects,'' he said. ''Genetic engineering like this is playing Russian roulette with the building blocks of life, and sooner or later we're bound to hit the loaded chamber.''

The paper stated that none of the biopharmaceuticals in development have completed all of the U.S. regulatory hurdles, although some have progressed through preclinical and clinical trials. It calls for further studies ''to establish the safety and efficacy of biopharmaceuticals produced using transgenic animals.''

So far, scientists have worked mostly with transgenic cows, pigs, and goats, Keefer said. Pigs especially have been used as models to study heart disease, organ transplantation, and eye disease, while the milk from cows and goats has been a major source for biopharmaceuticals.

The paper said transgenic animals are being engineered to produce human antibodies that scientists hope can be used to treat infections, cancer, and autoimmune diseases. Others genes are being tweaked to create proteins that would usually have to be harvested from human blood. The paper says that can combat challenges the human blood supply faces, such as shortages and the transmission of HIV.

''Development of genetically engineered animals as production systems for human biopharmaceutical and blood products has great potential for biomedical applications with regard to these limitations,'' the paper said.

It also can be a cheaper method to harvest the products and can provide agriculture companies significantly higher prices than traditional animal products, the paper said. While the technology is promising, the CAST paper notes the difficulties ahead.

''It is apparent that unless a biopharmaceutical produced by transgenic animals offers clear and significant advantages compared with more conventional products or procedures, it is unlikely to receive regulatory approval or attain commercial viability,'' the paper said.

It said using management practices such at those now in place for meat and milk production systems could help with acceptance of the new technology.

''As scientists continue to perfect technologies in the near future, more applications of transgenic animals for the treatment of human diseases will become available,'' according to a statement from John Bonner, CAST's executive vice president. (Amy Lorentzen, AP)