Obtaining ‘spare’ organs, developed in animals and available for transplantation in humans, is an objective pursued by different research groups around the world.
Although in 2022 several xenotrasplantes experimental, such as implanting a genetically modified pig heart into a Baltimore patient suffering from serious heart disease; This type of approach is still far from reaching the clinic. First, important biotechnological challenges posed by the ‘jump’ between species must be resolved, such as hyperacute rejection after grafting or the risk of zoonoses.
Research led by scientists from Harvard University and the company eGenesis paves this path by having managed to implant genetically edited pig kidneys in macaques and achieving notable survival figures. One of the transplanted specimens lived more than two years with the kidney graft. Details of the research are published in the journal Nature.
To minimize the risk of rejection and the possibility of transmission of porcine viruses with the transplant, the researchers made 69 genetic modifications in the donor animal, a Yucatan pig.
These modifications can be grouped into three blocks: first, they eliminated three glycan antigens, ‘markers’ present on the surface of cells that induce immediate rejection. In addition, they introduced changes so that the animal cells expressed seven human genes with the aim of improving tolerance and neutralizing other phenomena associated with hyperacute rejection. And finally, they inactivated all copies of the genetics related to porcine retroviruses.