Susumu Tonegawa

Susumu Tonegawa
(1939)

Japanese molecular biologist and immunologist who was awarded the Nobel Prize for Physiology or Medicine in 1987 for his fundamental discoveries concerning the body's production of antibodies.
Tonegawa received a B.S. degree from Kyoto University in 1963 and earned a Ph.D. in biology from the University of California, San Diego in 1969. He was a member of the Basel Institute for Immunology in Switzerland from 1971 to 1981 and taught biology at the Massachusetts Institute of Technology from 1981.

Tonegawa's research explained how the immune system can produce a vast diversity of antibodies, each of which reacts with and counteracts the effects of a separate antigen (a foreign molecule or microbe). Prior to Tonegawa's work it was not known how the B lymphocytes (the cells that produce antibodies) could with their limited number of genes produce the millions of differently structured antibodies that are specific to a comparable diversity of antigens. In the 1970s Tonegawa proved in a series of experiments that approximately 1,000 pieces of genetic material in the antibody-manufacturing portion of the B lymphocyte can be shuffled or recombined into different sequences, the resulting variations enabling the production of as many as one billion different types of antibodies, each specific to a different antigen. A fundamental mechanism in the immune system was thus revealed.