I took physics for my PhD because I thought that physical laws—constant across the whole Universe—had to be the most exciting, the most fundamental, stuff to study. As I got older, I became interested in life. I sort of stumbled into studying the immune system when I worked with a well-known immunologist, Jack Strominger, at Harvard University, after my PhD I’ve been studying the human immune system for over 15 years now.
What excites me about the immune system is that it’s an area of biology where a lot is not fully understood. It’s easy to hit the frontier. Why do some people get cancer or autoimmune diseases, and not others? In a database of 18 million people, there are four with compatibility genes similar to mine. And 6 percent of people in the 18 million are completely unique. However you view your place in the universe, some part of your individuality—your uniqueness—comes from the versions of these genes that you have inherited. So, studying immunology is, at this level, also a study of genetic differences between people.
What evidence do you have to support your idea?
This story has unraveled in a global adventure spanning 60 years, working out the science behind medical transplants and immunology, leading to our eventual understanding of how and why compatibility genes are crucial to our health. This is a revolution in our understanding of the human body, but not one that came in a single Eureka moment; this knowledge has come from experiments happening in different places across the globe over decades.
Every big thinker has predecessors to whom he is indebted. Who laid the foundation for you to build your idea? Who is your hero?
My book begins with Peter Medawar who, working in Oxford in the early 1950s, carried out several groundbreaking experiments, which won him a Nobel Prize, alongside Australian [Sir Frank] Macfarlane Burnet.
Seeing the agony of airmen suffering from drastic skin burns at a War Wounds Hospital in Oxford in 1940 focused Medawar’s mind on solving the difficulties that surgeons had in getting skin transplantation to work. His research went on to establish that the difficulties in medical transplantation were caused by a reaction from the recipient’s immune cells. This, together with theoretical ideas developed by Burnet, helped establish basic principles about how our immune system works.
In essence, they realized that the immune system recognizes and destroys substances that are not part of you—germs or transplanted organs. This implied that transplantation was not just about getting the surgery right. Up until this time, most surgeons thought if they could perform a technically perfect graft, the transplantation would work. But this was wrong; there was a fundamental barrier of an immune reaction to be overcome in order for skin grafts between genetically different people to work, because transplanted cells or tissues are detected as not being part of you. Genetic matching between people and the use of immune suppressive drugs make clinical transplantation work today, and both directly build upon Medawar and Burnet’s insights.
What is new about your thinking?