One potential solution to a persistent shortage of organ donors is to modify the DNA of pig organs in order to make them more of a match for human transplants. However, a significant issue is the potential for transmission of viruses, along with the possibility of rejection.
Now, the BBC reports, scientists have taken a major step toward addressing the problem.
Harvard University’s Professor George Church and colleagues have used a tool called Crispr to “edit” pig DNA and make organs more suitable for transplanting to people.
The team also edited genes in pig embryos in order to remove porcine endogenous retrovirus, which could be passed on during transplants. Although there was still a small amount of transmission, the modified pig cells did not easily pass the retrovirus on to human cells anymore.
Church, who partially-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 (human to animal transplants) 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.”
The bad news
Despite the major steps forward, real-world use of the transplant method is still many years down the line. And of course, there are issues beyond the pure science.
Dr. Sarah Chan, an expert from the University of Edinburgh, told the BBC: “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, she added, “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.”