Genetically Modified Pigs May Be A New Source Of Transplantable Organs
Organ Transplantation is one of the most complex medical procedures that currently exist. A particular reason for this complexity is because the human immune system can distinguish self from non-self. As a result, it can reject transplanted organs from a donor if the antigens in the organ's cells don't match to that of the patient's cells. This hurdle is the primary reason for the long waiting list of patients desperately waiting for an organ transplant because finding a close match is very hard. According to the U.S. Department of Health and Human Services, the disparity between supply and demand for organs has been widening since 2003 as shown in the graph below.
By looking at the current situation, we can deduce that depending solely on humans as a source for transplantable organs is not sustainable. These were the exact thoughts that ran through the employees at eGenesis, a biotech startup founded in 2015 by two renowned geneticists Drs. George Church and Luhan Yang whose primary goal is to bridge the gap between supply and demand for transplantable organs by xenotransplantation (a process by which an animal's organ is used for an organ transplant procedure).
One of their primary genetic experiments that has caught media attention is their effort to make pig organs transplantable. Even though the organs of a pig are similar to human organs in terms of size and function, xenotransplantation using pigs hasn't been achieved because the antigens present in the pig's cells can cause organ rejection or disease in the patient. In order to make a pig's organs more suitable for transplantation, researchers sampled a few pig cells and used CRISPR gene editing technology to remove the specific genes that code for the antigens that make the organs untransplantable. Then, they cloned these genetically edited cells and brought them back to their earliest developmental stage to transplant their nucleuses into eggs to grow genetically modified piglets that may harbor transplantable organs. Because the epigenetic patterns in a real embryo cell's DNA can't be copied to a cloned embryo's DNA, most cloned animals die before or soon after birth but eGenesis somehow has 15 healthy cloned piglets of which the oldest one is 4 months old.
The research being done at eGenesis is a classic case where science has been used for the good of humanity. The company hopes that some day in the future they can try out the first xenotransplantation using a pig's organs. Even though that day may be a few years from now, all we can do is hope that it succeeds so that there won't be a long waiting list of organ transplant patients in the future.
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