CRISPR-startup transplant pig organs of monkeys to understand how safe it is for people

The company eGenesis involved in the editing of genes, and conducts experimentsto resolve the critical shortage of human organs available for transplantation. In 2017, Harvard geneticist George Church predicted that pork organs with edited genes will be transplantirovannam people after a couple of years — maybe even a year.

“I was wrong”, now recognized Church.

His startup eGenesis announced their ambitious plans to use technology for editing genes CRISPR to modify pigs so that their organs can be safely transplanted into people without rejection. Thus it would be possible to solve the critical shortage of human organs available for transplant.

However, people such tests have not been conducted. Instead, the company is currently testing pig organs in monkeys in Boston. The experiments held by the chief surgeon of the General hospital James Markmann.

Is it possible to transplant human organs pigs?

“What we do is a necessary step,” says Markmann. “It would be difficult to put the modified body of a person without experiencing it on the big animal”.

No Markman or eGenesis does not describe in detail which bodies are studied or what types of monkeys involved in the experiments, which are said to include the most high-tech pig organs ever created surgeons.

For decades, doctors wanted to use a pigs to solve the shortage of organs, when their kidneys, heart and even lungs to patients-to people for replacement organs that have stopped working. Now more than 100,000 people in the United States are on the transplant list.

Over the past few years, scientists have reached important turning points in “xenotransplantation”. Scientists from the National Institute of health has managed to keep beating pig hearts in baboons (along with heart monkey) for about two years. At the end of last year, German surgeons reported that several baboons have survived for about six months after their heart had been replaced by pork.

These experiments were conducted using pigs, genetically modified Rivivicor, a subsidiary of United Therapeutics. Animals have genetic changes that are supposed to prevent immediate rejection by the human body stop the formation of blood clots and to compensate for other types of immune attacks.

Thanks to scientific advances, transplant surgeons are now discussing when we can take a risk and conduct the operation on a human being.

“We already have a Chevy. Perhaps even BMW. Do we need to wait for a Ferrari? There will come a time when you just want to ride,” says Devin Eckhoff, Director of the Department of transplantation medical school University of Alabama at Birmingham.

However, before the pig organs could be tested on humans, should solve some key problems. The results with monkeys were not very consistent. Regulators have not publicly stated under which conditions they will agree to testing on humans, and there is a debate about how much needs to be modified pigs.

Company Church — eGenesis — became notorious, boosting the role of CRISP in the creation of pigs with multiple genetic modifications. In 2015, the co-founder and chief scientist Lujan Yang has demonstrated that it can make changes from 62 to deactivate viruses that naturally lurk in the genome of pigs.

In addition, Yang said that her company currently had a “double digit” number of editing genes (through cutting and adding), to reduce the chance of organ rejection by the immune system. These changes are probably similar to changes created by Revivicor. Yang calls his pigs “most advanced” of genetically modified animals on Earth.

In 2017, speaking before the Carnegie institution, the Church declared that “we hope to start the transplant on humans within a year”.

But these terms are unrealistic. Yang believes that the biggest remaining obstacle for the whole region to achieve consistent results of transplantation from pigs to monkeys. Although some baboons lived for months with the bodies of pigs, other animals soon died. Scientists do not yet fully understand why. “We feel that there is some biological reason for it,” says Yang. “We understand and try to fix it”.

This requires a huge amount of pig organs. Yang said that eGenesis has produced more than 100 pigs in the United States, and its Chinese partner Qihan Biotech, based in Hangzhou, have raised hundreds, experimenting with various genetic changes. The rules do not allow you to move the pigs and their organs between countries.

“I think we will learn much more when I transplant several organs with the same mods and see how they behave,” says Markmann.

When it comes to the use of animals, such as pigs and baboons, the company tried to be as careful as possible. They don’t say where pigs. In an interview with Markman I would not say the word “monkey”, he would say “large animal”. Animal rights activists from PETA are against the research because “the pig is individuals, not spare parts”.

There are also disputes about how many genetic changes do we need to really. Muhammad Mohiuddin, program Director of cardiac xenotransplantation in the School of medicine of the University of Maryland, believes that the elimination of the viral genes is redundant and could harm an animal, will lead to undesirable consequences. Instead, ideally, it would edit the eight or nine genes and raise a pig with lots of usable organs, instead of to raise one pig for a heart transplant, and the other for kidney. Other organs should not be discarded.

Markmann says that previously published experiments on monkeys and his own work gives him optimism: genetically modified pigs will indeed become a valuable source of organs for humans.

“The fact that the organs of pigs live for six to twelve months or a few years, this is extremely good and suggests that it is possible. Everyone understands that we are at a critical moment.”

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