CRISPR Drapes Invisibility Cloak over Stem Cells
“An international research team has used CRISPR-Cas9 gene editing to render induced pluripotent stem cells (iPSCs) invisible to the immune system, a bioengineering sleight of hand that initial in vivo tests suggest could open the door to generating stem cells for universal transplantation. The new approach, developed by scientists at the University of California, San Francisco (UCSF), involves disabling two histocompatibility complex genes, and overexpressing the transmembrane protein CD47 on iPSCs. In vivo tests suggested that engineered human iPSC-derived cardiac cells were undetected by the immune system in mouse recipients, and showed evidence of rudimentary tissue differentiation.
““This is the first time anyone has engineered cells that can be universally transplanted and can survive in immunocompetent recipients without eliciting an immune response,” said Tobias Deuse, MD, the Julien I.E. Hoffman, MD, endowed chair in cardiac surgery at UCSF, who led the research, and is lead author of the team’s published paper in Nature Biotechnology. “Our technique solves the problem of rejection of stem cells and stem cell-derived tissues, and represents a major advance for the stem cell therapy field. The researchers’ paper is titled, Hypoimmunogenic derivatives of induced pluripotent stem cells evade immune rejection in fully immunocompetent allogeneic recipients.”