What the immune system of man has in its advanced development is what we call immunological memory, so that once it sees something for the first time, when it sees it the second or the third time, it can respond against it in a way that's much more accelerated than when it sees it for the first time.
The slow rejection of the foreign skin grafts fascinated me. How could the host distinguish another person's skin from his own?
The immune system's goal is to protect the body against invaders either from without, such as microbes, or from within, such as cancers and different types of neoplastic transformation.
You can put a kidney in your body - and somewhere down the line, your body might reject it.
The production of antibody is not the only, nor I believe the most important, manifestation of immunity, but for reasons both historical and of experimental convenience, antibody is likely to remain the touchstone of immunological theory.
The immune system constantly creates genes on the fly that are specific to the things that show up in the body. It's amazing.
Although we often discussed the idea of research on the nature of antigen recognition by T cells in the laboratory in the late Seventies while I was still in Basel, the real work did not start until the early Eighties in my new laboratory at M.I.T.
I like to think that when Medawar and his colleagues showed that immunological tolerance could be produced experimentally, the new immunology was born.
The immune system has evolved the capacity to react specifically with a very large number of foreign molecules with which it had no previous contact while avoiding reactivity for autologous molecules, naturally antigenic in other species or in other individuals of the same species.
When an animal is infected, either naturally or by experimental injection, with a bacterium, virus, or other foreign body, the animal recognises this as an invader and acts in such a way as to remove or destroy it.
What attracted me to immunology was that the whole thing seemed to revolve around a very simple experiment: take two different antibody molecules and compare their primary sequences.
