Genetically modified pigs as next human transplant donors

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A group of U.S. researchers from Harvard Medical School have found a way to make pig organs more suitable organ donors for humans.

In a paper published in the Science journal, geneticist George Church and a group of researchers used the CRISPR method to genetically modify the pig's DNA.

According to the United Press International, the CRISPR tool uses the protein Cas9 to direct the RNA into the pig's cell.

BBC reveals that the new CRISPR tool essentially allows scientists to remove and play around with DNA. With this recent study, the researchers used the tool to deactivate a retrovirus that can be passed on from pigs to humans and causing foreign organs to be rejected by the human body.

The Science paper describes how the tool was used to destroy elements of the porcine endogenous retrovirus or PERV in 62 areas in the pig's DNA. Inside the lab, the modified cells were found to be 1000 times less likely to infect human cells with PERV.

Prof George Church explains what makes this discovery monumental. In an interview with BBC he states, "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," Church says.

Although the results of the study will be beneficial for patients, Dr. Sarah Chan from the University of Edinburg also acknowledges that several issues may also arise from using pig organs on humans. She said in her statement to 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."

A recent report by Reuters mentions some of these ethical issues. In China, biologists have sparked a debate after conducting an experiment that involved modifying the genetic makeup of human embryos.

Church is already trying to take the study a step further. Science reveals that Church is one of the co-founders of eGenesis, a biotechnology company.

The company has successfully produced genetically modified pig embryos with the PERV sequences deactivated. Church's group hopes to have PERV-inactivated embryos ready for injecting in a mother pig by 2016.