X-Message-Number: 12645
Date: Tue, 26 Oct 1999 18:28:09 -0400
From: Jan Coetzee <>
Subject: Transplant brain cells

Scientists Transplant 'Improved' Brain Cells

 WASHINGTON (Reuters) - Scientists said Monday they had transplanted
brain cells from pigs
 into monkeys using a new process that made the neurons hold up longer
under attack from the
 monkeys' immune systems.

 The idea is to come up with ways to treat Parkinson's and other
diseases involving the
 destruction of brain cells.

 The team, from Harvard Medical School and Connecticut-based Alexion
Pharmaceuticals, Inc.,
 said they had protected the pig cells from attack by the immune system
using a product being
 developed by Alexion.

 Dr. Ole Isacson and colleagues at Harvard's McLean Hospital told a
meeting of the Society for
 Neuroscience in Miami that the transplanted brain cells survived and

 ``To my knowledge, this study represents the first successful
engraftment of pig neurons into
 primates,'' Isacson said in a statement.

 Parkinson's is caused when certain brain cells, which produce a
chemical, dopamine --
 important for movement and muscle control -- start dying off. A few
Parkinson's patients have
 had brain cells from embryos injected into their brains in the hope of
correcting the problem.

 But such cells are rare and the practice is controversial. Some
scientists hope to use animal
 brain cells instead, but the body can recognize these as foreign cells
and reject them.

 The researchers used an Alexion product called C5 Complement Inhibitor.
A monoclonal
 antibody, it is a genetically engineered human protein currently being
tested in human patients in
 Phase II clinical trials for the treatment of various chronic
inflammatory disorders.

 Alexion first genetically engineered pigs to grow brain cells that lack
a certain sugar on the
 surface and thus do not look quite so foreign to the human or primate

 Then they took the dopamine-producing cells from the pigs and further
genetically engineered
 them to express human complement inhibitor proteins -- which further
protected them from
 immune attack.

 These cells worked to restore brain function in monkeys made to develop
 symptoms. Adding the C5 inhibitor made the cells last even longer, they

 ``We are now focusing on optimizing manufacturing and beginning to
explore the process of
 initiating human clinical trials,'' Dr. Leonard Bell, president and
chief executive officer of
 Alexion, said in a statement.

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