Scientists have used the powerful CRISPR system to make a major breakthrough in adapting pig organs for human use, and are working to overcome other obstacles. If successful, organs harvested from pigs could potentially save tens of thousands of lives per year.
Most organisms are relatively similar once you get under the hood, so to speak. Hearts, lungs, kidneys, and other major organs are found in nearly every animal. Genetically, however, while many of these organs are very similar, they are largely incompatible.
By tweaking the genetic material inside the pig’s cells, researchers may be able to make their organs more compatible for human use. Pigs make prime candidates for such editing because their organs are similar in size to human organs.
Before pig organs can be used, however, researchers will have to overcome two major obstacles. First, at least 62 DNA sequences in pigs are actually the remnants of the porcine endogenous retrovirus, otherwise known as PERV. This virus has demonstrated the potential to infect humans, thus any organs with the DNA remnants could pose a threat to people.
Second, human immune systems have demonstrated to respond very aggressively to pig cells. Unfortunately, the body cannot really distinguish between friendly and unfriendly cells, but instead usually focuses on finding and destroying foreign cells and organisms.
When a transplant is made, including with human organs, the body will often respond by trying to destroy the organ in question. Organs from genetically similar people, such as close relatives, is usually accepted more willingly.
Scientists have long known about these challenges, and now they have the tool needed to potentially overcome them. The CRISPR system allows researchers to use the Cas9 protein to insert RNA into cells, and thus modify genetic codes.
Using CRISPR, researchers have been able to decrease PERV transmissions 1000-fold using gene editing. Now the question is if they can make the organs more compatible with the immune system. Researchers are working on this second part, but results haven’t been published.
Pigs for organs will raise questions, but is needed
Undoubtedly, even if scientists are able to create pig-human compatible organs, it would raise some ethical questions. The use of animals in research, and even for consumption, has drawn quite a bit of heat from groups like PETA.
Still, for the loved ones of people in need of organs, the life of a pig won’t seem like much in exchange for the life of a person. As many as 30 people die per day due to a lack of an organ donor. This should come as no surprise given that the wait list for organs is roughly 125,000 people long.
Given that the United States is home to only about 5 percent of th world’s population, the global demand for organs is much, much higher.