40 | SCIENCE ILLUSTRATED
Scientists test pig organs
in monkeys and humans
Scientists are already experimenting with altering pig organs to fit humans.
Pig gene editing is to make sure that the organs are not rejected by our immune systems.
Lungs
The thousands of tiny
blood vessels in the
lungs make the organ
extremely hard to transplant.
Monkeys, who have received pig
lungs, only survive for a few days.Corneas
In China, several patients
have regained their
eyesight following pig
cornea implants. The pig cells were
removed from the cornea in order not to
challenge the patient's immune system.Kidneys
A baboon survived for
136 days after having its
kidneys replaced by a
genetically edited pig kidney. The
ground-breaking result offers new
hope for patients with kidney failure.Pancreas
Chinese scientists have
reported on successful
experiments with
diabetes patients, who could
subsequently make do with less
medication.
human immune system, which normally
protects us against infections, but the
system attacks any foreign material in the
human body, so organs from other people
and animals are aggressively combated. That
is because immune cells can distinguish
between even slight differences between the
body’s own proteins and the proteins on the
surface of the transplanted organs. And as
immune cells will only tolerate the proteins
they are used to, a brand new method is
required to solve the organ shortage problem.MYTHOLOGICAL CREATURES
Scientists found inspiration for the next
major advance in an unexpected place:Ancient Greece. The Greeks created myths
about chimeras, i.e. awesome hybrids of
different animals. In the 1980s, creative
scientists took the first step towards
realising the Greek visions, creating a chimera
based on two different mouse species. Stem
cells from one species were injected into an
embryo from another species, and theSTATUS: More experiments will
hopefully confirm the safety and
functionality of the Chinese method.
STATUS: Scientists are altering
several pig genes to make the
kidney more fit for humans.STATUS: Scientists gene splice
the pig, allowing the liver to control
the patient's immune response.STATUS: Scientists aim to remove
the monkey's own heart, inserting
the pig heart instead.STATUS: Scientists hope to have
genetically edited pig lungs ready
for human experiments in 2020.STATUS: Successful surgery has
been carried out, but the method
has only been approved in China.CLAUS LUNAU & BILL LING/GETTY IMAGES
Liver
Experiments have
shown that pig
livers are rejected
by the immune systems of
monkeys and humans.Heart
When a genetically
edited pig heart is
transplanted into a
baboon, it is not rejected, and
the monkey survives.HUMANS ORGANS