Dolly-Maker Announces World's First Cloned Pigs

1:23 PM EST; March 14, 2000; London, UK (CNN) -- The British biopharmaceutical company that created Dolly the sheep has produced the world's first cloned pigs, the group announced Tuesday. The birth of the five cloned piglets could usher in breakthroughs in animal-to-human organ transplants. PPL Therapeutics said that the healthy piglets were born March 5th in Blacksburg, VA. They were cloned from an adult sow using a technique similar to the one that three years ago produced Dolly, the first clone of an adult mammal. Independent analysis of the DNA of the five piglets verified that they were cloned from the sow, the company said.

Scientists have studied pigs for several years as possible organ donors for humans. The cloning could herald advances that allow scientists to genetically engineer pigs so that their organs or cells would be more readily accepted by the human body, making them more easily transplantable.

"I think this is a big step forward they've made. I applaud it," said Dr. Fritz Bach of Harvard Medical School, who studies genetic and immunological aspects of transplants from animals to people.

May Boost Animal-to-Human Transplants

Genetic engineering is but one potential benefit, Bach said. In addition, scientists could simply clone pigs that prove exceptionally suited for transplants to humans, he said. Analysts estimate the market for organ transplants could be worth as much as $10 billion a year. Cellular therapies, in which altered cells are transplanted to humans to treat conditions such as diabetes, would add considerably more to that sum.

Company scientists plan to try to "knock out" a gene that helps produce a sugar in pig cells that the human immune system recognizes as foreign. The gene triggers an immune response in the human body, prompting it to reject the organ. Three new genes would then be introduced into the pig cells, and the transplant patient would receive a blood transfusion containing modified cells taken from the pig supplying the organ. Scientists hope this process will reduce long-term rejection of transplanted organs. "All the known technical hurdles have been overcome," said Ron James, PPL's managing director. "It is now a case of combining the various strategies into one male and one female pig and breeding from these."

Could Humans Catch Pig Diseases?

The idea of using animal organs for transplant, known as xenotransplantation, is controversial because some believe diseases could cross from pigs to humans. Bach stressed that ethical issues about animal-to-human transplants, mainly the risk of introducing new germs into humans, must be resolved before new transplant procedures are used. [Editor's Note: Regarding the possibility of retroviruses -- or so-called silent viruses -- being transmitted from pigs (raised under sterile conditions) to human organ recipients, PPL spokespersons countered that "such a possibility is purely hypothetical." At this time, there is no evidence that such a risk is an actual concern.]

But some scientists say usable animal organs are needed because of the chronic shortage of human organs. Up to 68,000 people in the United States and 50,000 in Europe are waiting for livers, kidneys, and hearts. The lists increase by 15 percent a year while the number of organ donors is dwindling. Genetically engineered pigs, whose organs are about the same size as humans, could be bred quickly to boost the supply. "An end to the chronic organ shortage is now in sight," James said. PPL said it expects to begin clinical trials in the next four years.

The names of the first cloned piglets each have their own significance. Millie was named for the millennium. Christa, Alexis and Carrel were named after Dr. Christiaan Barnard, who performed the first human heart transplant, and Dr. Alexis Carrel, who won the Nobel prize in 1912 for his work in the field of transplantation. As for the one named Dotcom -- "Any association with dotcoms right now seems to have a very positive influence on a company's valuation," James said.

U.S. Government-Supported Research

PPL's U.S. staff in Blacksburg, VA who cloned the piglets received partial support from the U.S. Government's National Institute of Standards and Technology (NIST).

The company's shares rose 19 percent to a record high after the announcement, valuing the Edinburgh-based group at about $150.9 million.

Dolly Creators Claim Cloning Pigs
by
Kia Shant'e Breaux,
Associated Press Writer

4:56 PM EST; March 14, 2000; Blacksburg, VA (AP) -- The company that cloned Dolly the sheep has produced the first cloned pigs, five piglets named Millie, Christa, Alexis, Carrel, and Dotcom that raise hopes for a new source of transplants for humans. "I think this is a big step forward they've made. I applaud it," said Dr. Fritz Bach of Harvard Medical School, who studies genetic and immunological aspects of transplants from animals to people and was not involved in the cloning project.

The piglets, delivered by Caesarean-section on March 5th at the Virginia-Maryland College of Veterinary Medicine, were produced by a subsidiary of PPL Therapeutics of Edinburgh, Scotland, which nearly four years ago created Dolly, the world's first clone of an adult mammal. "The birth of these pigs was a very significant accomplishment," Dave Ayares, PPL's Vice President of Research, said at a news conference Tuesday. "Essentially, it has the potential to revolutionize the field of organ transplantation."

The five female pigs were cloned from an adult sow named Destiny using a slightly different technique than the one that produced Dolly. Independent tests of the DNA of the piglets confirmed they were clones of the sow, the company said. The identical baby pigs playfully wrestled and nibbled on each other's ears inside a wooden pen at the news conference. Their mother, however, was not present. PPL touted the clones as a major step toward achieving its xenograft objectives, which would create genetically altered pigs whose organs and cells could be successfully transplanted in humans. Pigs are physiologically one of the closest animals to humans.

Imutran, a Cambridge, England-based company pursuing similar research, called PPL's announcement "interesting news." "It is potentially a useful technology to develop new lines of pigs for [transplant]," the company said. "However, the next step is to see if the technology can be applied to developing genetically-modified animals whose organs can be transplanted into humans without being rejected." However, the idea of using animal organs for transplant, known as xenotransplantation, is controversial because some persons believe viral illnesses could cross from pigs to humans. [Editor's Note: At this time, such a premise is purely hypothetical.]

PPL scientists plan to try to eliminate a gene responsible for incorporating in pig cells a sugar group recognized by the human immune system as "foreign." The gene triggers an immune response in the human body, prompting it to rapidly reject the organ. PPL said transplantation of genetically- altered pig organs could be tested on humans in four years and that analysts believe the market for them could be worth $6 billion for solid organs alone. Other uses include cellular therapies, such as transplantable cells that produce insulin for the treatment of diabetes.

"We hope in the very near-term to overcome the shortage of human organs," said Ayares, who noted that ultrasound tests performed Tuesday confirmed additional pig-cloning pregnancies at the company's farm in Blacksburg, VA. The only connection the births have to the veterinary school at Virginia Tech is that the university provided the clinical services for the delivery. All of the research was conducted and funded by PPL.

Despite the potential solution for organ shortages, the pig cloning drew criticism from animal rights activists. "There's always a reason given to validate these Frankenstein-like experiments," said Lisa Lange, a spokeswoman for Norfolk-based People for the Ethical Treatment of Animals (PETA). "Animals are not test tubes with tails, and they are not commodities to be marketed." Ayares countered that for years pigs have been raised and slaughtered for food. "I don't think our pigs are being mistreated," Ayares said. "Indeed, they live better than most other pigs." [Editor's Note: Are all members of PETA vegetarians?]

The names of the first cloned piglets each have their own significance. Millie was named for the millennium. Christa, Alexis, and Carrel were named after Dr. Christiaan Barnard, who performed the first human heart transplant, and Dr. Alexis Carrel, who won the Nobel prize in 1912 for his work in the field of transplantation. And what about Dotcom? "Any association with dotcoms right now seems to have a very positive influence on a company's valuation," said Ron James, PPL's Managing Director.

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On the Net: ppl-therapeutics.com