Our innate defence against disease is based on the ability of our cells to distinguish themselves from those of others. While critical to our integrity, our immune system hampers organ transplant procedures, since the body naturally rejects foreign tissue. Proteins on the surface of our body cells send ‘safe’ signals to our immune system. Cells from different individuals exhibit different proteins on their surface, which immune cells interpret as ‘danger’ signals. This prompts an immune response that specifically targets and eradicates ‘invaders’. Sir Peter Medawar, born on this day in 1915, paved the way for the success of organ transplants today. He described how immune reactions led to rejection, and suggested that immunosuppressive drugs be used to prevent failure, which later won him a Nobel Prize. Thousands of lives are saved or dramatically improved each year courtesy of organ transplants in the UK.
Written by Brona McVittie
BPoD stands for Biomedical Picture of the Day. Managed by the MRC Clinical Sciences Centre the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.