Scientists want to make pig organs for humans’

According to new research, gene-editing method could
one day make pig organs
suitable for use in people.
Prof George Church and
colleagues used a technique
called Crispr to alter the DNA of
pig cells to create a better match
for humans.
The early work, in the journal
Science, aims to address
concerns about rejection and
infection by viruses embedded in
pig DNA.
If successful, it could be an
answer to the shortage of
human donor organs.
Years more research is needed
before genetically modified pigs
could be bred to grow organs
for people.
Gene editing
Crispr is a relatively new scientific
tool that lets scientists snip and
play around with the code of life
– DNA.
Prof Church, from Harvard
University, used it to inactivate a
retrovirus present in the pig cell
line.
This porcine endogenous
retrovirus is potentially risky
because it can infect human cells
– at least in the lab.
In tests on early pig embryos,
Prof Church was able to eliminate
all 62 copies of porcine
endogenous retroviruses from
the pig cells using Crispr.
Next, he checked if the modified
pig cells would still easily pass
the retrovirus on to human cells.
They did not, although there was
still a small amount of
transmission.
Prof Church says the discovery
holds great promise for using
animal organs in people – what
doctors call xenotransplantation.
Prof Church, who part-owns a
company that wants to develop
modified pigs to grow organs,
said: "It was kind of cool from
two stand points.
"One is it set a record for Crispr
or for any genetic modification
of an animal, and it took away
what was considered the most
perplexing problem to be solved
in the xenotransplantation field.
"With immune tolerance, that
completely changes the
landscape as well.
"These two things, immune
tolerance and now getting rid of
all the retroviruses, means we
have a clear path."
Dr Sarah Chan, an expert from
the University of Edinburgh, said:
"Even once the scientific and
safety issues have been
addressed, we should be mindful
of the possible cultural concerns
and societal impacts associated
with more widespread use of pig
organs for human
transplantation.
"Nonetheless, the results of the
study are valuable both as a
proof of principle and a potential
step towards therapeutic
advances in this area of much-
needed research."
-BBCnews/health