Scientists at Massachusetts General Hospital are looking for ways to reprogram humans with failing organs so that their bodies will accept replacement organs transplanted from other species.
One of the reasons animal organs do not work in humans is that the human immune system, in common with other primates, reacts violently to alpha-Gal, a carbohydrate that occurs in the cells of other mammals. The rejection response is so immediate and so strong that immunosuppressive drugs can do little to prevent it.
A possible solution being investigated by Dr John Iacomini and colleagues is to insert the animal gene responsible for producing alpha-Gal into the prospective recipient's bone marrow where immune cells are generated, with the hope that the immune cells wouldn't attack it if it was already part of the environment in which they were born so to speak.
But first, true, to their mindset, these scientists needed an animal model. They created one by manipulating mice not to produce alpha-Gal. Like humans, these mice produced antibodies to alpha-Gal so that their immune systems rejected it. The next step was to reprogram the bodies of these manipulated mice not to produce these antibodies by incorporating the gene that produces alpha-Gal back into their genetic make-up. This manipulation has achieved some success in getting these highly artificial, but still living and sentient, animals not to reject transplanted organs.
The next step, presently underway, is to see if this technique can prevent baboons' immune systems from rejecting pig organs.
The ultimate hope is that the procedure might be used to trick the human body into accepting replacement organs from other animals.
ref. AP Report, September 18, 1998
Comment: A great deal of effort and money, and a great deal of animal suffering, has gone into altering the genetic material of animals by incorporating human genes in their bodies in an attempt to make them susceptible to human diseases. This enables scientists to study human pathogens and look for ways to defeat them. The creation of the now patented cancer-susceptible onco mouse at Harvard University was heralded as a major scientific breakthrough, but no miraculous advances in treating human cancer have followed. The problem is that although they have actually produced animals capable of harboring human disease organism, the animal is not going to react in the same way that a human would. The only sensible, scientific way to study human disease is by looking at the people suffering from it.LETTER FROM CIVITAS PUBLISHED IN
This report dangles the hope that humans might be altered to accept organ transplants from other species without mentioning the very real danger of introducing new plagues of animal diseases in humans. Meanwhile, scientists at other institutions are busy trying to combat rejection of xenotransplants by rearranging pigs to carry human genes.
The Chronicle of Higher Education
Vincent Kiernan's presumption that xenotransplantation experiments from pigs to humans contemplated by the Mayo Clinic "would illustrate medical researchers' success at solving once-daunting technical barriers to cross-species transplants" is unwarranted.
Aside from how many people would suffer and die from this unnatural procedure, there is the matter of how many other people might also suffer, and perhaps die, from illness caused by an unrecognized pig virus. As prominent virologists like Jonathan Allan at Southwest Foundation for Biomedical Research have pointed out: You can't screen for a virus that you don't know is present.
It is important to bear in mind that over 20 million died in 1918 from a swine flu virus that was transmitted to humans, and many more were made seriously ill. Also, the scientific consensus is that AIDS originated from a simian virus transmitted to humans from green monkeys, and the new variant of inevitably fatal Creuzfeldt-Jacob disease (CJD) appears to have been transferred from sheep to cows to humans.
There is a whole world of viruses that the human body has either learned to live with or has developed defensive barriers against. When confronted with an implant that bypasses all normal barriers, however, the body is not always able to muster its defenses quickly enough to resist the already implanted intruder. The virus is then afforded a whole new environment in which to mutate and multiply and use as a base of operations for infecting other humans.
It is commendable that scientists want to help people who suffer from organ failure, but more people could be helped much sooner without the threat of unknown viruses if government and private agencies would step up their efforts to convince the public to donate organs of family members who have died. This last resort would not correct whatever caused the original organ failure, however, and the recipients would probably have to take immuno-suppressive drugs for the rest of their lives.
The real solution to the problem is to promote healthy diet and lifestyles so that fewer organs would fail. Unfortunately, this approach, which would prevent much of the suffering humans now endure, lacks financial incentive for the corporations that manufacture the drugs used to treat illness and, in this case, scramble genetic material between pigs and humans. - Bina Robinson
We had a very nice response to this letter from someone who was awaiting a transplant. On his behalf, we point out that many of the people whose lives depend on getting a transplant are in that position through no fault of their own. They did all the right things and are still in trouble. Indeed, life is not fair. Our aim is to see that they get whatever help the medical profession is capable of providing. Given the state of technology today, the best means of doing so is to persuade EVERYBODY to practice healthy eating, get at least a little exercise, and avoid pollutants as much as possible.
EVERYBODY would benefit by feeling better, avoiding expensive medical bills, and not needing to undergo a transplant. There might then be enough organs for those whose need is unavoidable.
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