Using sugar-coated proteins to trick the immune system in heart transplants

Targeting recipient antigen-presenting cells with sialic acid-modified alloantigen to promote transplantation tolerance

The success of heart transplants in people with heart failure is limited because of late-stage organ rejection and the side effects of giving people immunosuppressive drugs. Scientists are therefore looking for ways to adapt the immune system to tolerate a donor heart without the need for current immunosuppressive drugs. Professor Giovanna Lombardi is investigating the way cancer cells and infectious agents escape the immune system. Some bacteria and cancer cells have special ‘sugar-coated’ molecules on their surface, which fools the immune system into allowing these cells to grow and spread. The sugar coating works to increases the number of regulatory cells in the immune system, which to dampen down the immune response. Previous research shows that switching these regulatory cells on is an important step in making the immune system more tolerant of a donor heart. Using this trick of nature, Professor Lombardi aims to use sugar-coated molecules from the transplanted heart to fool the immune system, preventing it from attacking the transplant. In this project she will test whether these molecules can prolong survival of skin and heart transplants in mice, and will also study which immune cells contribute to the effects. This work will help us to better understand how the immune system develops tolerance for a transplanted organ.