Pigs have become increasingly popular in medical research. Their significance now paves the way for research into xenotransplantation, for the purpose of saving human lives.

Pigs’ organs are similar to human organs, in terms of size and function. The animals can also be bred in large numbers, hence be made readily available when required.

Furthermore, research on genetic modification of pigs had been carried out for years.

Pigs may well be the next best candidate for human transplants


One major problem of xenotransplantation is the introduction of viruses that can infect host cells.

Pigs carry porcine endogenous retroviruses (PERVs), which have the potential to infect human cells when a pig organ is transplanted into a human. This can possibly cause tumours or leukaemia, leading to greater health problems.

In a study published in the August 2017 edition of Science journal, a group of scientists have now come up with a way to edit and deactivate these retroviruses in a pig cell line. This is carried out using the powerful genome-editing technology CRIPSPR-Cas9, the same technology being used to clone Dolly the sheep.

The “designer piglets” were successfully produced with inactivated and harmless PERVs, making it safer for cross-species transplantation. According to the scientists, the piglets are “growing and are still healthy.”

The latest findings offer promising results, bringing the research community a step closer towards safe transplantation of animal organs into human hosts.

Experts’ opinions on the pigs “designed” for xenotransplantation


Xenotransplantation carries risks, particularly of transmission of known or as yet unrecognised xenogeneic infectious agents, from animals to humans. There is also a risk of transmission from recipients of such transplants to their contacts and the public at large.

For sure, pig organs are still not yet safe for transplant to humans.

Firstly, experts highlight major concerns like the danger of organ rejection. Pig organs still need to be edited further to be made more compatible for human hosts.

More time is also needed to monitor the “designer piglets” to ensure that they stay healthy. Furthermore, the CRISPR technology was known to sometimes cuts piece of DNA that it was not programmed to do. This in turn could have negative outcomes.

Nevertheless, the latest research serves as a form of “safety check” and removes the potential risk for cross-species transmission of these retroviruses.

Scientists also agreed that the research brings pig organs a step closer to safe transplantation. The use of the CRISPR technology has proven valuable in deactivating the PERVs – eliminating the known potential risks.

Nevertheless, the study researchers themselves anticipate that clinical trials using engineered pig organs could kick off in 10 years’ time. This could open up a brand-new chapter in making pig organs viable and compatible for transfer into humans.

While more research still needs to be done, the “PERV-inactivated pigs” could serve as a strong foundation for further genetic engineering research.

On the ground, transplantation has always been a sensitive issue with many challenges. With a growing waiting list for transplantation, the ongoing intense research offers a huge potential of saving lives for the generations to come. MIMS

Read more:
5 unusual genes that create real-life superheroes
American scientists use CRISPR to modify human embryos
World’s first human-pig hybrid: Medical breakthrough or ethical dilemma?

Sources:
https://www.navs.org/what-we-do/keep-you-informed/science-corner/animals-used-in-research/pigs-in-research/#.WY-eBlEjHIU
http://www.who.int/transplantation/xeno/en/
http://science.sciencemag.org/content/early/2017/08/09/science.aan4187
https://www.theatlantic.com/science/archive/2017/08/pig-organs-for-humans/536307/
https://www.theverge.com/2017/8/10/16121104/pig-organs-xenotransplantation-retroviruses-gene-editing-crisspr
http://edition.cnn.com/2017/08/10/health/crispr-pig-retrovirus-organ-transplant-study/index.html