Tonegawa, Susumu (1939– )

Japanese molecular biologist who was awarded a Nobel Prize for Physiology or Medicine in 1987 for his work on the process by which genes alter to produce a range of different antibodies. He discovered that around 1,000 genes are used by the human body to generate billions of different antibodies. Antibodies are molecules that defend the body against infection. When a foreign substance, called an antigen, enters the body, it is attacked and destroyed by antibodies.

When Tonegawa began his work, scientists knew that antibody molecules were produced by genes in white blood cells called B lymphocytes or B cells. However, there were a limited number of genes in the B cells and scientists could not explain how a huge number of different antibodies were produced from so few genes. Tonegawa discovered that the genes were shuffled and recombined in a random manner as a cell grows, producing billions of different gene combinations which could then produce billions of different antibodies.

Tonegawa was born in Nagoya. He was educated at Kyotoa University and the University of California at San Diego, USA, receiving his doctorate in 1968. He moved to the Basel Institute of Immunology in Switzerland in 1971. In 1981 he was appointed professor at the Center for Cancer Research at the Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.