Donor lungs genetically treated

Donor lungs can be genetically modified so that they are no longer recognized as foreign and rejected by the immune system, an Austrian-German research team discovered in mini pigs. With this type of donor organ treatment, rejection reactions can also be avoided in human lung recipients. This would enable them to live without the need for medication to suppress the immune system, the researchers wrote in the journal “Science Translational Medicine”.

After lung transplants, the new organs only survive for more than five years in half of the patients, reports the team led by Rainer Blasczyk from the Hannover Medical School. But even here, this is only possible by suppressing the body’s own immune system (immunosuppression), which makes those affected very susceptible to infectious diseases, among other things.

During a transplant, the organs inevitably have to go through an “ex vivo” phase in which they are neither in the donor nor the recipient’s body, say the researchers. During this time, they can be specifically modified.

The scientists did this with a line of experimental animals called “Göttingen mini pigs”. They used genetic engineering to suppress the display of surface features in the donor lungs. In most cases (five out of seven) the genetically modified organs remained unaffected by the immune system in the new animal. They survived the entire observation period of two years, although possible immune reactions were only suppressed with medication for a few weeks after the operation. In the transplant of “normal” lungs, however, the foreign organs were all rejected within three months.