Scientists have grown universal stem cells using CRISPR engineering

Human heart muscle cells derived from new universal stem cells

Scientists from the University of California San Francisco first grew universal stem cells using CRISPR gene editing technology to produce pluripotent stem cells that can be transplanted to any patient without causing an immune response.

Pluripotent stem cells are cells that can become cells of any type that the body needs. A little more than ten years ago, revolutionary progress showed how fully formed adult cells can effectively transform into pluripotent stem cells. These induced pluripotent stem cells (iPSC) promised to change regenerative medicine, but clinical applications were not very successful.

“There are many problems with iPSC technology, but the biggest obstacles are quality control and reproducibility,” explains Tobias Diez, lead author of the new study. “We do not know why some cells reprogram more easily than others, but most scientists agree that we are not yet sure about their clinical use. Because of this, most of the tests on individualized iPSC therapy have been suspended. ”
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When growing iPSC, scientists need to begin a complex and time-consuming process, including the collection of adult cells from each independent patient, in order to avoid an immune response during subsequent cell transplantation. New research is aimed at developing a new process for growing universal iPSC, which can be used by any patient.

To do this, scientists used CRISPR to turn off two specific genes that produce proteins that signal that they are targets of the immune system. However, scientists have found that these disabled proteins still trigger natural killer (NK) immune cells in order to attack. Another piece of the puzzle was obtained from the CD47 gene. The researchers found that NK activity can be inhibited by overexpression of the CD47 gene in iPSC.

In various animal tests, researchers found that these new, universal iPSCs could be transplanted into mice with different immune profiles, without any immune response. Taking another step forward, the researchers used new iPSCs to grow human heart cells, which they transplanted into humanized chimeric mice. Not only did they not have any immune response, cells began to form the earliest buds of the heart muscle.

“This is the first time that we have grown engineering cells that can be transplanted and that can survive in any immunocompetent recipient without causing an immune response,” says Deese.

Although there is still a lot of work to be done to develop specific safe therapies, this progress lays the foundation for these therapies to be much cheaper and, I hope, much more effective. If these new cells prove to be safe and beneficial for patients, they will eliminate the costly and burdensome process of personalizing future stem cell therapies.

“Our technology can benefit a wider range of people, and the cost of it is much lower than with any personalized approach,” says Deese. "We need to make our cells only once, and we get a line that can be applied universally."

University of California San Francisco