‘About a year ago, scientists grafted genetically modified pigs’ hearts into baboons. And now, the team reports that the baboons and their pig hearts are doing just fine. The engineering grafts haven’t been rejected, and ones like it may be ready for humans with end stage heart failure one day soon.
The biggest challenge with transplants using animal organs (or xenotransplantation) is preventing the hosts from seeing their donor parts as foreign. In the past, organs that haven’t been genetically tweaked last no more than six months in primates before they’re rejected. One of the reasons pigs were chosen for this study is because their anatomy is already compatible with humans; pig valves are already being swapped for human heart valves.
To further help pig parts evade our immune systems, a team from the National Heart, Lung, and Blood Institute (NHLBI) of the U.S. National Institutes of Health added several human genes to the pig genome — while removing (or knocking out) genes that would trigger immune responses in humans…’ (I Fucking Love Science).